International Convention for the Safety of Life at Sea (SOLAS), 1974

Chapter II-1Construction – Structure, subdivision and stability, machinery and electrical installations

Contents

Part 8-2 Subdivision, watertight and weathertight integrity

Regulation 9 Double bottoms in passenger ships and cargo ships other than tankers

Regulation 10 Construction of watertight bulkheads

Regulation 11 Initial testing of watertight bulkheads, etc

Regulation 12 Peak and machinery space bulkheads, shaft tunnels, etc

Regulation 13 Openings in watertight boundaries below the bulkhead deck in passenger ships 75 Regulation 13-1 Openings in watertight bulkheads and internal decks in cargo ships

Regulation 14 Passenger ships carrying goods vehicles and accompanying personnel

Regulation 15 Openings in the shell plating below the bulkhead deck of passenger ships and the freeboard deck of cargo ships

Regulation 15-1 External openings in cargo ships

Regulation 16 Construction and initial tests of watertight closures

Regulation 16-1 Construction and initial tests of watertight decks, trunks, etc

Regulation 17 Internal watertight integrity of passenger ships above the bulkhead deck

Regulation 17-1 Integrity of the hull and superstructure, damage prevention and control on ro-ro passenger ships

Part 8-3 Subdivision load line assignment for passenger ships

Regulation 18 Assigning, marking and recording of subdivision load lines for passenger ships … 85

Part 8-4 Stability management

Regulation 19 Damage control information

Regulation 19-1 Damage control drills for passenger ships

Regulation 20 Loading of ships

Regulation 21 Periodical operation and inspection of watertight doors, etc., in passenger ships

Regulation 22 Prevention and control of water ingress, etc

Regulation 22-1 Flooding detection systems for passenger ships carrying 36 or more persons .. . 89 Regulation 23 Special requirements for ro-ro passenger ships

Regulation 24 Additional requirements for prevention and control of water ingress, etc., in cargo ships

Regulation 25 Water level detectors on single hold cargo ships other than bulk carriers

Regulation 25-1 Water level detectors on multiple hold cargo ships other than bulk carriers and tankers

Part C Machinery installations

Regulation 26 General

Regulation 27 Machinery

Regulation 28 Means of going astern

Regulation 29 Steering gear

Regulation 30 Additional requirements for electric and electrohydraulic steering gear

Regulation 31 Machinery controls

Regulation 32 Steam boilers and boiler feed systems

Contents

Regulation 33 Steam pipe systems

Regulation 34 Air pressure systems

Regulation 35 Ventilating systems in machinery spaces

Regulation 35-1 Bilge pumping arrangements

Regulation 36 [Blank]

Regulation 37 Communication between navigation bridge and machinery space

Regulation 38 Engineers' alarm

Regulation 39 Location of emergency installations in passenger ships

Part D Electrical installations

Regulation 40 General

Regulation 41 Main source of electrical power and lighting systems

Regulation 42 Emergency source of electrical power in passenger ships

Regulation 42-1 Supplementary emergency lighting for ro-ro passenger ships

Regulation 43 Emergency source of electrical power in cargo ships

Regulation 44 Starting arrangements for emergency generating sets

Regulation 45 Precautions against shock, fire and other hazards of electrical origin

Part E Additional requirements for periodically unattended machinery spaces

Regulation 46 General

Regulation 47 Fire precautions

Regulation 48 Protection against flooding

Regulation 49 Control of propulsion machinery from the navigation bridge

Regulation 50 Communication

Regulation 51 Alarm system

Regulation 52 Safety systems

Regulation 53 Special requirements for machinery, boiler and electrical installations

Regulation 54 Special consideration in respect of passenger ships

Part F Alternative design and arrangements

Regulation 55 Alternative design and arrangements … 123

Part G Ships using low-flashpoint fuels

Regulation 56 Application

Regulation 57 Requirements for ships using low-flashpoint fuels

Unified interpretations for chapter 11-1 … 127

Appendices to unified interpretations of chapter 11-1 … 157

General

Regulation 1

Application*

1.1 Unless expressly provided otherwise, this chapter shall apply to ships the keels of which are laid or which are at a similar stage of construction on or after 1 January 2009.

1.1.1 Unless expressly provided otherwise, parts B, B-1, B-2 and B-4 of this chapter shall only apply to ships:

.1 for which the building contract is placed on or after 1 January 2020; or

.2 in the absence of a building contract, the keel of which is laid or which are at a similar stage of construction on or after 1 July 2020; or

.3 the delivery of which is on or after 1 January 2024.

SEE INTERPRETATION 1

1.1.2 Unless expressly provided otherwise, for ships not subject to the provisions of paragraph 1.1.1 but constructed on or after 1 January 2009, the Administration shall:

.1 ensure that the requirements for parts B, 8-1, B-2 and B-4 which are applicable under chapter 11-1 of the International Convention for the Safety of Life at Sea, 1974, as amended by resolutions MSC.216(82), MSC.269(85) and MSC.325(90) are complied with; and

.2 ensure that the requirements of regulations 8-1.3 and 19-1 are complied with.

SEE INTERPRETATION 1

1.2 For the purpose of this chapter, the term a similar stage of construction means the stage at which:

.1 construction identifiable with a specific ship begins; and

.2 assembly of that ship has commenced comprising at least 50 tonnes or 1% of the estimated mass of all structural material, whichever is less.

1.3 For the purpose of this chapter:

.1 the expression ships constructed means ships the keels of which are laid or which are at a similar stage of construction;

.2 the expression ships constructed on or after 1 January 2024 means ships:

.1 for which the building contract is placed on or after 1 January 2024; or

.2 in the absence of a building contract, the keel of which is laid or which are at a similar stage of construction on or after 1 July 2024; or

.3 the delivery of which is on or after 1 January 2028 .

.3 the expression all ships means ships constructed before, on or after 1 January 2009;

* Refer to Unified interpretation of the application of regulations governed by the building contract date, the keel laying date and the delivery date for the requirements of the SOLAS and MARPOL Conventions (MSC-MEPC.5/Circ.8).

.4 a cargo ship, whenever built, which is converted to a passenger ship shall be treated as a passenger ship constructed on the date on which such a conversion commences.

SEE INTERPRETATION 1

2 Unless expressly provided otherwise, for ships constructed before 1 January 2009, the Administration shall:

.1 ensure that the requirements which are applicable under chapter 11-1 of the International Convention for the Safety of Life at Sea, 1974, as amended by resolutions MSC.1(XLV), MSC.6(48), MSC.11(55), MSC.12(56), MSC.13(57), MSC.19(58), MSC.26(60), MSC.27(61), resolution 1 of the 1995 SOLAS Conference, MSC.47(66), MSC.57(67), MSC.65(68), MSC.69(69), MSC.99(73), MSC.134(76), MSC.151(78) and MSC.170(79) are complied with; and

.2 ensure that the requirements of regulations 8-1.3 and 19-1 are complied with.

3 All ships which undergo repairs, alterations, modifications and outfitting related thereto shall continue to comply with at least the requirements previously applicable to these ships. Such ships, if constructed before the date on which any relevant amendments enter into force, shall, as a rule, comply with the requirements for ships constructed on or after that date to at least the same extent as they did before undergoing such repairs, alterations, modifications or outfitting. Repairs, alterations and modifications of a major character and outfitting related thereto shall meet the requirements for ships constructed on or after the date on which any relevant amendments enter into force, insofar as the Administration deems reasonable and practicable.* SEE INTERPRETATION 2

4 The Administration of a State may, if it considers that the sheltered nature and conditions of the voyage are such as to render the application of any specific requirements of this chapter unreasonable or unnecessary, exempt from those requirements individual ships or classes of ships entitled to fly the flag of that State which, in the course of their voyage, do not proceed more than 20 miles from the nearest land.

5 In the case of passenger ships which are employed in special trades for the carriage of large numbers of special trade passengers, such as the pilgrim trade, the Administration of the State whose flag such ships are entitled to fly, if satisfied that it is impracticable to enforce compliance with the requirements of this chapter, may exempt such ships from those requirements, provided that they comply fully with the provisions of:

.1 the rules annexed to the Special Trade Passenger Ships Agreement, 1971; and

.2 the rules annexed to the Protocol on Space Requirements for Special Trade Passenger Ships, 1973.

Regulation 2

Definitions For the purpose of this chapter, unless expressly provided otherwise:

1 Subdivision length (L 5 ) of the ship is the greatest projected moulded length of that part of the ship at or below deck or decks limiting the vertical extent of flooding with the ship at the deepest subdivision draught.

2 Amidships is at the middle of the length (L).

3 Aft terminal is the aft limit of the subdivision length.

4 Forward terminal is the forward limit of the subdivision length.

5 Length (L) is the length as defined in the International Convention on Load Lines in force.

6 Freeboard deck is the deck as defined in the International Convention on Load Lines in force.

7 Forward perpendicular is the forward perpendicular as defined in the International Convention on Load Lines in force.

* Refer to Interpretation of alterations and modifications of a major character (MSC.1/Circ.1246).

Part A General

8 Breadth (B) is the greatest moulded breadth of the ship at or below the deepest subdivision draught.

9 Draught (d) is the vertical distance from the keel line at:

.1 amidships, for ships subject to the provisions of regulation 11-1/1.1.1.1; and

.2 the mid-point of the subdivision length (Ls), for ships not subject to the provIsIons of regulation 11-1/1.1.1.1 but constructed on or after 1 January 2009, to the waterline in question.

10 Deepest subdivision draught (ds) is the summer load line draught of the ship.

11 Light service draught (d1) is the service draught corresponding to the lightest anticipated loading and associated tankage, including, however, such ballast as may be necessary for stability and/or immersion. Passenger ships should include the full complement of passengers and crew on board.

12 Partial subdivision draught (dp) is the light service draught plus 60% of the difference between the light service draught and the deepest subdivision draught.

13 Trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft:

.1 perpendiculars respectively, as defined in the International Convention on Load Lines in force, for ships subject to the provisions of regulation 11-1/1.1.1.1; and

.2 terminals respectively, for ships not subject to the provisions of regulation 11-1 / 1.1.1.1 but constructed on or after 1 January 2009, disregarding any rake of keel.

14 Permeability (µ) of a space is the proportion of the immersed volume of that space which can be occupied by water.

SEE INTERPRETATION 3

15 Machinery spaces are spaces between the watertight boundaries of a space containing the main and auxiliary propulsion machinery, including boilers, generators and electric motors primarily intended for propulsion. In the case of unusual arrangements, the Administration may define the limits of the machinery spaces.

16 Weathertight means that in any sea conditions water will not penetrate into the ship.

17 Watertight means having scantlings and arrangements capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions. In the damaged condition, the head of water is to be considered in the worst situation at equilibrium, including intermediate stages of flooding.

18 Design pressure means the hydrostatic pressure for which each structure or appliance assumed watertight in the intact and damage stability calculations is designed to withstand.

19 Bulkhead deck in a passenger ship means the uppermost deck:

.1 to which the main bulkheads and the ship's shell are carried watertight, for ships subject to the provisions of regulation 11-1/1.1.1.1; and

.2 at any point in the subdivision length (Ls) to which the main bulkheads and the ship's shell are carried watertight and the lowermost deck from which passenger and crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter, for ships not subject to the provisions of regulation 11-1/1.1.1.1 but constructed on or after 1 January 2009. The bulkhead deck may be a stepped deck. In a cargo ship not subject to the provisions of regulation 11-1/1.1.1.1 but constructed on or after 1 January 2009, the freeboard deck may be taken as the bulkhead deck.

20 Deadweight is the difference in tonnes between the displacement of a ship in water of a specific gravity of 1.025 at the draught corresponding to the assigned summer freeboard and the lightweight of the ship.

SEE INTERPRETATION 4

21 Lightweight is the displacement of a ship in tonnes without cargo, fuel, lubricating oil, ballast water, fresh water and feedwater in tanks, consumable stores, and passengers and crew and their effects.

SEE INTERPRETATION 5

22 Oil tanker is the oil tanker defined in regulation 1 of Annex I of the Protocol of 1978 relating to the International Convention for the Prevention of Pollution from Ships, 1973.

23 Ro-ro passenger ship means a passenger ship with ro-ro spaces or special category spaces as defined in regulation 11-2/3.42.

24 Bulk carrier means a bulk carrier as defined in regulation Xll/1.1.

25 Keel line is a line parallel to the slope of the keel passing amidships through:

.1 the top of the keel at centreline or line of intersection of the inside of shell plating with the keel if a bar keel extends below that line, on a ship with a metal shell; or

.2 in wood and composite ships, the distance is measured from the lower edge of the keel rabbet.

When the form at the lower part of the midship section is of a hollow character, or where thick garboards are fitted, the distance is measured from the point where the line of the flat of the bottom continued inward intersects the centreline amidships.

26 2008 IS Code means the International Code on Intact Stability, 2008, consisting of an introduction, part A (the provisions of which shall be treated as mandatory) and part B (the provisions of which shall be treated as recommendatory), as adopted by resolution MSC.267(85), provided that:

.1 amendments to the introduction and part A of the Code are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I thereof; and

.2 amendments to part B of the Code are adopted by the Maritime Safety Committee in accordance with its Rules of Procedure.

27 Coal-based Ship Construction Standards for Bulk Carriers and Oil Tankers means the International Goal- based Ship Construction Standards for Bulk Carriers and Oil Tankers, adopted by the Maritime Safety Committee by resolution MSC.287(87), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I thereof.

28 /CF Code means the International Code of Safety for Ships using Gases or other Low-Flashpoint Fuels as adopted by the Maritime Safety Committee of the Organization by resolution MSC.391(95), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I.

29 Low-flashpoint fuel means gaseous or liquid fuel having a flashpoint lower than otherwise permitted under regulation 11-2/4.2.1.1.

Regulation 3

Definitions relating to parts C, D and E For the purpose of parts C, D and E, unless expressly provided otherwise:

1 Steering gear control system is the equipment by which orders are transmitted from the navigating bridge to the steering gear power units.

Steering gear control systems comprise transmitters, receivers, hydraulic control pumps and their associated motors, motor controllers, piping and cables.

2 Main steering gear is the machinery, rudder actuators, steering gear, power units, if any, and ancillary equipment and the means of applying torque to the rudder stock (e.g. tiller or quadrant) necessary for effecting movement of the rudder for the purpose of steering the ship under normal service conditions.

3 Steering gear power unit is:

.1 in the case of electric steering gear, an electric motor and its associated electrical equipment;

.2 in the case of electrohydraulic steering gear, an electric motor and its associated electrical equipment and connected pump; or

.3 in the case of other hydraulic steering gear, a driving engine and connected pump.

4 Auxiliary steering gear is the equipment other than any part of the main steering gear necessary to steer the ship in the event of failure of the main steering gear but not including the tiller, quadrant or components serving the same purpose.

5 Normal operational and habitable condition is a condition under which the ship as a whole, the machinery, services, means and aids ensuring propulsion, ability to steer, safe navigation, fire and flooding safety, internal and external communications and signals, means of escape, and emergency boat winches, as well as the designed comfortable conditions of habitability, are in working order and functioning normally.

6 Emergency condition is a condition under which any services needed for normal operational and habitable conditions are not in working order due to failure of the main source of electrical power.

7 Main source of electrical power is a source intended to supply electrical power to the main switchboard for distribution to all services necessary for maintaining the ship in normal operational and habitable conditions.

8 Dead ship condition is the condition under which the main propulsion plant, boilers and auxiliaries are not in operation due to the absence of power.

9 Main generating station is the space in which the main source of electrical power is situated.

10 Main switchboard is a switchboard which is directly supplied by the main source of electrical power and is intended to distribute electrical energy to the ship's services.

11 Emergency switchboard is a switchboard which in the event of failure of the main electrical power supply system is directly supplied by the emergency source of electrical power or the transitional source of emergency power and is intended to distribute electrical energy to the emergency services.

12 Emergency source of electrical power is a source of electrical power, intended to supply the emergency switchboard in the event of a failure of the supply from the main source of electrical power.

13 Power actuating system is the hydraulic equipment provided for supplying power to turn the rudder stock, comprising a steering gear power unit or units, together with the associated pipes and fittings, and a rudder actuator. The power actuating systems may share common mechanical components (i.e. tiller, quadrant and rudder stock) or components serving the same purpose.

14 Maximum ahead service speed is the greatest speed which the ship is designed to maintain in service at sea at the deepest seagoing draught.

15 Maximum astern speed is the speed which it is estimated the ship can attain at the designed maximum astern power at the deepest seagoing draught.

16 Machinery spaces are all machinery spaces of category A and all other spaces containing propelling machinery, boilers, oil fuel units, steam and internal combustion engines, generators and major electrical machinery, oil filling stations, refrigerating, stabilizing, ventilation and air conditioning machinery, and similar spaces, and trunks to such spaces.

17 Machinery spaces of category A are those spaces and trunks to such spaces which contain:

.1 internal combustion machinery used for main propulsion;

.2 internal combustion machinery used for purposes other than main propulsion where such machinery has in the aggregate a total power output of not less than 375 kW; or

.3 any oil-fired boiler or oil fuel unit.

18 Control stations are those spaces in which the ship's radio or main navigating equipment or the emergency source of power is located or where the fire recording or fire control equipment is centralized.

19 Chemical tanker is a cargo ship constructed or adapted and used for the carriage in bulk of any liquid product listed in either:

.1 chapter 17 of the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk adopted by the Maritime Safety Committee by resolution MSC.4(48), hereinafter referred to as "the International Bulk Chemical Code", as may be amended by the Organization; or

.2 chapter VI of the Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk adopted by the Assembly of the Organization by resolution A.212(VII), hereinafter referred to as "the Bulk Chemical Code", as has been or may be amended by the Organization, whichever is applicable.

20 Gas carrier is a cargo ship constructed or adapted and used for the carriage in bulk of any liquefied gas or other products listed in either:

.1 chapter 19 of the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk adopted by the Maritime Safety Committee by resolution MSC.5(48), hereinafter referred to as "the International Gas Carrier Code", as may be amended by the Organization; or

.2 chapter XIX of the Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk adopted by the Organization by resolution A.328(IX), hereinafter referred to as "the Gas Carrier Code", as has been or may be amended by the Organization, whichever is applicable.

Structure of ships

Regulation 3-1

Structural, mechanical and electrical requirements for ships In addition to the requirements contained elsewhere in the present regulations, ships shall be designed, constructed and maintained in compliance with the structural, mechanical and electrical requirements of a classification society which is recognized by the Administration in accordance with the provisions of regulation Xl-1/1, or with applicable national standards of the Administration which provide an equivalent level of safety.

Regulation 3-2

Protective coatings of dedicated seawater ballast tanks in all types of ships and double-side skin spaces of bulk carriers*

SEE INTERPRETATION 6

1 Paragraphs 2 and 4 of this regulation shall apply to ships of not less than 500 gross tonnage:

.1 for which the building contract is placed on or after 1 July 2008; or

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 January 2009; or

.3 the delivery of which is on or after 1 July 2012.t

2 All dedicated seawater ballast tanks arranged in ships and double-side skin spaces arranged in bulk carriers of 150 m in length and upwards shall be coated during construction in accordance with the Performance standard for protective coatings for dedicated seawater ballast tanks in all types of ships and double-side skin spaces of bulk carriers, adopted by the Maritime Safety Committee by resolution MSC.215(82), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I.

SEE INTERPRETATION 7

3 All dedicated seawater ballast tanks arranged in oil tankers and bulk carriers constructed on or after

1 July 1998, for which paragraph 2 is not applicable, shall comply with the requirements of regulation 11-1/3-2 adopted by resolution MSC.47(66).

4 Maintenance of the protective coating system shall be included in the overall ship's maintenance scheme. The effectiveness of the protective coating system shall be verified during the life of a ship by the

• Refer to Guidelines for the selection, application and maintenance of corrosion prevention systems of dedicated seawater ballast tanks (resolution A.798(19)). t Refer to Unified interpretation of "unforeseen delay in delivery of ships" (MSC.1/Circ.1247).

Administration or an organization recognized by the Administration, based on the guidelines developed by the Organization.*

SEE INTERPRETATION 7

Regulation 3-3

Safe access to tanker bows

1 For the purpose of this regulation and regulation 3-4, tankers include oil tankers as defined in regulation 2.22, chemical tankers as defined in regulation Vll/8.2 and gas carriers as defined in regulation Vll/11.2.

2 Every tanker shall be provided with the means to enable the crew to gain safe access to the bow even in severe weather conditions. Such means of access shall be approved by the Administration based on the guidelines developed by the Organization.t

Regulation 3-4

Emergency towing arrangements and procedures

1 Emergency towing arrangements on tankers

1.1 Emergency towing arrangements shall be fitted at both ends on board every tanker of not less than 20,000 tonnes deadweight.

1.2 For tankers constructed on or after 1 July 2002 :

.1 the arrangements shall, at all times, be capable of rapid deployment in the absence of main power on the ship to be towed and easy connection to the towing ship. At least one of the emergency towing arrangements shall be pre-rigged ready for rapid deployment; and

.2 emergency towing arrangements at both ends shall be of adequate strength taking into account the size and deadweight of the ship, and the expected forces during bad weather conditions. The design and construction and prototype testing of emergency towing arrangements shall be approved by the Administration, based on the guidelines developed by the Organization.:J:

1.3 For tankers constructed before 1 July 2002, the design and construction of emergency towing arrangements shall be approved by the Administration, based on the guidelines developed by the Organization.:J:

2 Emergency towing procedures on ships

2.1 This paragraph applies to:

.1 all passenger ships, not later than 1 January 2010;

.2 cargo ships constructed on or after 1 January 201 O; and

.3 cargo ships constructed before 1 January 2010, not later than 1 January 2012.

2.2 Ships shall be provided with a ship-specific emergency towing procedure. Such a procedure shall be carried aboard the ship for use in emergency situations and shall be based on existing arrangements and equipment available on board the ship.

* Refer to Revised guidelines for maintenance and repair of protective coatings (MSC.1/Circ.1330/Rev.1). t Refer to Revised guidelines for safe access to tanker bows (resolution MSC.62(67)/Rev.1). * Refer to Guidelines on emergency towing arrangements for tankers (resolution MSC.35(63), as amended) and LL.3/Circ.130, section 5.

Part A-1 Structure of ships

2.3 The procedure* shall include:

.1 drawings of fore and aft deck showing possible emergency towing arrangements;

.2 inventory of equipment on board that can be used for emergency towing;

.3 means and methods of communication; and

.4 sample procedures to facilitate the preparation for and conducting of emergency towing operations.

Regulation 3-5

New installation of materials containing asbestost SEE INTERPRETATION 8

1 This regulation shall apply to materials used for the structure, machinery, electrical installations and equipment covered by the present Convention.

2 From 1 January 2011, for all ships, new installation of materials which contain asbestos shall be prohibited.

Regulation 3-6

Access to and within spaces in, and forward of, the cargo area of oil tankers and bulk carriers SEE INTERPRETATION 9

1 Application SEE INTERPRETATION 10

1.1 Except as provided for in paragraph 1.2, this regulation applies to oil tankers of 500 gross tonnage and over and bulk carriers, as defined in regulation IX/ 1, of 20,000 gross tonnage and over, constructed on or after

1 January 2006.

1.2 Oil tankers of 500 gross tonnage and over constructed on or after 1 October 1994 but before 1 January

2005 shall comply with the provisions of regulation 11-1 / 12-2 adopted by resolution MSC.27(61).

2 Means of access to cargo and other spaces

2.1 Each space shall be provided with means of access to enable, throughout the life of a ship, overall and close-up inspections and thickness measurements of the ship's structures to be carried out by the Administration, the Company, as defined in regulation IX/1, and the ship's personnel and others as necessary. Such means of access shall comply with the requirements of paragraph 5 and with the Technical provisions for means of access for inspections, adopted by the Maritime Safety Committee by resolution MSC.133(76)+, as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I.

SEE INTERPRETATION 11

2.2 Where a permanent means of access may be susceptible to damage during normal cargo loading and unloading operations or where it is impracticable to fit permanent means of access, the Administration may

• Refer to Guidelines for owners/operators on preparing emergency towing procedures (MSC.1/Circ.1255). t Refer to Information on prohibiting the use of asbestos on board ships (MSC.1/Circ.1374/Rev.1). t Amended by resolution MSC.158(78).

allow, in lieu thereof, the provision of movable or portable means of access, as specified in the Technical provisions, provided that the means of attaching, rigging, suspending or supporting the portable means of access forms a permanent part of the ship's structure. All portable equipment shall be capable of being readily erected or deployed by the ship's personnel.

SEE INTERPRETATION 12

2.3 The construction and materials of all means of access and their attachment to the ship's structure shall be to the satisfaction of the Administration. The means of access shall be subject to survey prior to, or in conjunction with, its use in carrying out surveys in accordance with regulation 1/10.

SEE INTERPRETATION 13

3 Safe access to cargo holds, cargo tanks, ballast tanks and other spaces

3.1 Safe access* to cargo holds, cofferdams, ballast tanks, cargo tanks and other spaces in the cargo area shall be direct from the open deck and such as to ensure their complete inspection. Safe access to double- bottom spaces or to forward ballast tanks may be from a pump-room, deep cofferdam, pipe tunnel, cargo hold, double-hull space or similar compartment not intended for the carriage of oil or hazardous cargoes.

SEE INTERPRETATION 14

3.2 Tanks, and subdivisions of tanks, having a length of 35 m or more, shall be fitted with at least two access hatchways and ladders, as far apart as practicable. Tanks less than 35 m in length shall be served by at least one access hatchway and ladder. When a tank is subdivided by one or more swash bulkheads or similar obstructions which do not allow ready means of access to the other parts of the tank, at least two hatchways and ladders shall be fitted.

SEE INTERPRETATION 15

3.3 Each cargo hold shall be provided with at least two means of access as far apart as practicable. In general, these accesses should be arranged diagonally, for example one access near the forward bulkhead on the port side, the other one near the aft bulkhead on the starboard side.

4 Ship Structure Access Manual

4.1 A ship's means of access to carry out overall and close-up inspections and thickness measurements shall be described in a Ship Structure Access Manual approved by the Administration, an updated copy of which shall be kept on board. The Ship Structure Access Manual shall include the following for each space:

.1 plans showing the means of access to the space, with appropriate technical specifications and dimensions;

.2 plans showing the means of access within each space to enable an overall inspection to be carried out, with appropriate technical specifications and dimensions. The plans shall indicate from where each area in the space can be inspected;

.3 plans showing the means of access within the space to enable close-up inspections to be carried out, with appropriate technical specifications and dimensions. The plans shall indicate the positions of critical structural areas, whether the means of access is permanent or portable and from where each area can be inspected;

.4 instructions for inspecting and maintaining the structural strength of all means of access and means of attachment, taking into account any corrosive atmosphere that may be within the space;

.5 instructions for safety guidance when rafting is used for close-up inspections and thickness measurements;

* Refer to Revised recommendations for entering enclosed spaces aboard ships (resolution A.1050(27)).

.6 instructions for the rigging and use of any portable means of access in a safe manner;

.7 an inventory of all portable means of access; and

.8 records of periodical inspections and maintenance of the ship's means of access.

SEE INTERPRETATION 16

4.2 For the purpose of this regulation "critical structural areas" are locations which have been identified from calculations to require monitoring or from the service history of similar or sister ships to be sensitive to cracking, buckling, deformation or corrosion which would impair the structural integrity of the ship.

SEE INTERPRETATION 17

5 General technical specifications

5.1 For access through horizontal openings, hatches or manholes, the dimensions shall be sufficient to allow a person wearing a self-contained air-breathing apparatus and protective equipment to ascend or descend any ladder without obstruction and also provide a clear opening to facilitate the hoisting of an injured person from the bottom of the space. The minimum clear opening shall not be less than 600 mm x 600 mm. When access to a cargo hold is arranged through the cargo hatch, the top of the ladder shall be placed as close as possible to the hatch coaming. Access hatch coamings having a height greater than 900 mm shall also have steps on the outside in conjunction with the ladder.

SEE INTERPRETATION 18

5.2 For access through vertical openings, or manholes, in swash bulkheads, floors, girders and web frames providing passage through the length and breadth of the space, the minimum opening shall be not less than

600 mm x 800 mm at a height of not more than 600 mm from the bottom shell plating unless gratings or other footholds are provided.

SEE INTERPRETATION 19

5.3 For oil tankers of less than 5,000 tonnes deadweight, the Administration may approve, in special circumstances, smaller dimensions for the openings referred to in paragraphs 5.1 and 5.2, if the ability to traverse such openings or to remove an injured person can be proved to the satisfaction of the Administration.

Regulation 3-7

Construction drawings maintained on board and ashore

1 A set of as-built construction drawings* and other plans showing any subsequent structural alterations shall be kept on board a ship constructed on or after 1 January 2007.

2 An additional set of such drawings shall be kept ashore by the Company, as defined in regulation IX/1.2.

Regulation 3-8

Towing and mooring equipment SEE INTERPRETATION 20

1 Paragraphs 4 to 6 of this regulation apply to ships constructed on or after 1 January 2007.

2 Paragraphs 7 and 8 of this regulation only apply to ships:

.1 for which the building contract is placed on or after 1 January 2024; or

* Refer to As-built construction drawings to be maintained on board the ship and ashore (MSC/Circ.1135).

.2 in the absence of a building contract, the keel of which is laid or which is at a similar stage of construction on or after 1 July 2024; or

.3 the delivery of which is on or after 1 January 2027.

3 This regulation does not apply to towing arrangements provided in accordance with regulation 3-4.

4 Ships shall be provided with arrangements, equipment and fittings of sufficient safe working load to enable the safe conduct of all towing and mooring operations associated with the normal operation of the ship.

5 Arrangements, equipment and fittings provided in accordance with paragraph 4 above shall meet the appropriate requirements of the Administration or an organization recognized by the Administration under regulation 1/6.*

6 Each fitting or item of equipment provided under this regulation shall be clearly marked with any limitations associated with its safe operation, taking into account the strength of the supporting ship's structure and its attachment to it.

7 For ships of 3,000 gross tonnage and above, the mooring arrangement shall be designed, and the mooring equipment including lines shall be selected, in order to ensure occupational safety and safe mooring of the ship, based on the guidelines developed by the Organization.t Ship-specific information shall be provided and kept on board.+

8 Ships of less than 3,000 gross tonnage should comply with the requirement in paragraph 7 above as far as reasonably practicable, or with applicable national standards of the Administration.

9 For all ships, mooring equipment, including lines, shall be inspected and maintained in a suitable condition for their intended purposes.§

Regulation 3-9

Means of embarkation on and disembarkation from ships

1 Ships constructed on or after 1 January 2010 shall be provided with means of embarkation on and disembarkation from ships for use in port and in port-related operations, such as gangways and accommodation ladders, in accordance with paragraph 2, unless the Administration deems that compliance with a particular provision is unreasonable or impractical.'![

2 The means of embarkation and disembarkation required in paragraph 1 shall be constructed and installed based on the guidelines developed by the Organization.**

3 For all ships the means of embarkation and disembarkation shall be inspected and maintained'![ in suitable condition for their intended purpose, taking into account any restrictions related to safe loading. All wires used to support the means of embarkation and disembarkation shall be maintained as specified in regulation 111/20.4.

* Refer to the Guidance on shipboard towing and mooring equipment (MSC.1/Circ.1175) for ships constructed on or after 1 January

2007 but before 1 January 2024 and the Revised guidance on shipboard towing and mooring equipment (MSC.1/Circ.1175/Rev.1) for ships constructed on or after 1 January 2024. t Refer to the Guidelines on the design of mooring arrangements and the selection of appropriate mooring equipment and fittings for safe mooring (MSC.1/Circ.1619). * Refer to towing and mooring arrangement plan in the Guidelines on the design of mooring arrangements and the selection of appropriate mooring equipment and fittings for safe mooring (MSC.1/Circ.1619). § Refer to the Guidelines for inspection and maintenance of mooring equipment including lines (MSC.1/Circ.1620).

'II Circumstances where compliance may be deemed unreasonable or impractical may include where the ship:

.1 has small freeboards and is provided with boarding ramps; or

.2 is engaged in voyages between designated ports where appropriate shore accommodation/embarkation ladders (platforms) are provided. ** Refer to Guidelines for construction, installation, maintenance and inspection/survey of means of embarkation and disembarkation (MSC.1/Circ.1331).

Regulation 3-10

Goal-based ship construction standards for bulk carriers and oil tankers

SEE INTERPRETATION 21

1 This regulation shall apply to oil tankers of 150 m in length and above and to bulk carriers of 150 m in length and above, constructed with single deck, top-side tanks and hopper side tanks in cargo spaces, excluding ore carriers and combination carriers:

.1 for which the building contract is placed on or after 1 July 2016; or

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 July 2017; or

.3 the delivery of which is on or after 1 July 2020.

2 Ships shall be designed and constructed for a specified design life to be safe and environmentally friendly, when properly operated and maintained under the specified operating and environmental conditions, in intact and specified damage conditions, throughout their life.

2.1 Safe and environmentally friendly means the ship shall have adequate strength, integrity and stability to minimize the risk of loss of the ship or pollution to the marine environment due to structural failure, including collapse, resulting in flooding or loss of watertight integrity.

2.2 Environmentally friendly also includes the ship being constructed of materials for environmentally acceptable recycling.

2.3 Safety also includes the ship's structure, fittings and arrangements providing for safe access, escape, inspection and proper maintenance and facilitating safe operation.

2.4 Specified operating and environmental conditions are defined by the intended operating area for the ship throughout its life and cover the conditions, including intermediate conditions, arising from cargo and ballast operations in port, waterways and at sea.

2.5 Specified design life is the nominal period that the ship is assumed to be exposed to operating and/or environmental conditions and/or the corrosive environment and is used for selecting appropriate ship design parameters. However, the ship's actual service life may be longer or shorter depending on the actual operating conditions and maintenance of the ship throughout its life cycle.

3 The requirements of paragraphs 2 to 2.5 shall be achieved through satisfying applicable structural requirements of an organization which is recognized by the Administration in accordance with the provisions of regulation Xl-1/1, or national standards of the Administration, conforming to the functional requirements of the Goal-based Ship Construction Standards for Bulk Carriers and Oil Tankers.*

4 A Ship Construction File with specific information on how the functional requirements of the Goal- based Ship Construction Standards for Bulk Carriers and Oil Tankers have been applied in the ship design and construction shall be provided upon delivery of a new ship, and kept on board the ship and/or ashore and updated as appropriate throughout the ship's service. The contents of the Ship Construction File shall, at least, conform to the guidelines developed by the Organization.t

• The International goal-based ship construction standards for bulk carriers and oil tankers were adopted by resolution MSC.287(87) and their verification should be carried out in accordance with the Revised guidelines for verification of conformity with goal-based ship construction standards for bulk carriers and oil tankers (resolution MSC.454(100)). t Refer to Guidelines for the information to be included in a Ship Construction File (MSC.1/Circ.1343).

Regulation 3-11

Corrosion protection of cargo oil tanks of crude oil tankers

1 Paragraph 3 shall apply to crude oil tankers,* as defined in regulation 1 of Annex I to the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto, of 5,000 tonnes deadweight and above:

.1 for which the building contract is placed on or after 1 January 2013; or

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 July 2013; or

.3 the delivery of which is on or after 1 January 2016.

2 Paragraph 3 shall not apply to combination carriers or chemical tankers as defined in regulations 1 of Annexes I and II, respectively, to the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto. For the purpose of this regulation, chemical tankers also include chemical tankers certified to carry oil.

3 All cargo oil tanks of crude oil tankers shall be:

.1 coated during the construction of the ship in accordance with the Performance standard for protective coatings for cargo oil tanks of crude oil tankers, adopted by the Maritime Safety Committee by resolution MSC.288(87), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I; or

.2 protected by alternative means of corrosion protection or utilization of corrosion resistance material to maintain required structural integrity for 25 years in accordance with the Performance standard for alternative means of corrosion protection for cargo oil tanks of crude oil tankers, adopted by the Maritime Safety Committee by resolution MSC.289(87), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I.

4 The Administration may exempt a crude oil tanker from the requirements of paragraph 3 to allow the use of novel prototype alternatives to the coating system specified in paragraph 3.1, for testing, provided they are subject to suitable controls, regular assessment and acknowledgement of the need for immediate remedial action if the system fails or is shown to be failing. Such exemption shall be recorded on an exemption certificate.

5 The Administration may exempt a crude oil tanker from the requirements of paragraph 3 if the ship is built to be engaged solely in the carriage of cargoes and cargo handling operations not causing corrosion.t Such exemption and conditions for which it is granted shall be recorded on an exemption certificate.

Regulation 3-12

Protection against noise

1 This regulation shall apply to ships of 1,600 gross tonnage and above:

.1 for which the building contract is placed on or after 1 July 2014; or

* Refer to items 1.11.1 or 1.11.4 of the Supplement to the International Oil Pollution Prevention Certificate (Form B). t Refer to Revised guidelines on procedures for in-service maintenance and repair of coating systems for cargo oil tanks of crude oil tankers (MSC.1/Circ.1399/Rev.1) and Guidelines on exemptions for crude oil tankers solely engaged in the carriage of cargoes and cargo-handling operations not causing corrosion (MSC.1/Circ.1421).

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 January 2015; or

.3 the delivery of which is on or after 1 July 2018, unless the Administration deems that compliance with a particular provision is unreasonable or impractical.

2 On ships delivered before 1 July 2018 and:

.1 contracted for construction before 1 July 2014 and the keels of which are laid or which are at a similar stage of construction on or after 1 January 2009; or

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 January 2009 but before 1 January 2015, measures* shall be taken to reduce machinery noise in machinery spaces to acceptable levels as determined by the Administrationt. If this noise cannot be sufficiently reduced the source of excessive noise shall be suitably insulated or isolated or a refuge from noise shall be provided if the space is required to be manned. Ear protectors shall be provided for personnel required to enter such spaces, if necessary.

3 Ships shall be constructed to reduce onboard noise and to protect personnel from the noise in accordance with the Code on Noise Levels on Board Ships, adopted by the Maritime Safety Committee by resolution MSC.337(91), as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I. For the purpose of this regulation, although the Code on Noise Levels on Board Ships is treated as a mandatory instrument, recommendatory parts as specified in chapter I of the Code shall be treated as non-mandatory, provided that amendments to such recommendatory parts are adopted by the Maritime Safety Committee in accordance with its Rules of Procedure.

4 Notwithstanding the requirements of paragraph 1, this regulation does not apply to types of ships listed in paragraph 1.3.4 of the Code on Noise Levels on Board Ships.

• Refer to the Code on Noise Levels on Board Ships (resolution A.468(XII)). t Refer to Revised guidelines for the reduction of underwater radiated noise from shipping to address adverse impacts on marine life (MEPC.1/Circ.906).

Subdivision and stability

SEE INTERPRETATION 22

Regulation 4

General

1 Unless expressly provided otherwise, the requirements in parts B-1 to B-4 shall apply to passenger ships.

2 For cargo ships, the requirements in parts B-1 to B-4 shall apply as follows:

.1 In part B-1:

.1 unless expressly provided otherwise, regulation 5 shall apply to cargo ships and regulation 5-1 shall apply to cargo ships other than tankers, as defined in regulation I/2(h);

.2 regulation 6 to regulation 7-3 shall apply to cargo ships having a length (L) of 80 m and upwards, but may exclude those ships subject to the following instruments and shown to comply with the subdivision and damage stability requirements of that instrument:

.1 Annex I to MARPOL, except that combination carriers (as defined in SOLAS regulation 11-2/3.14) with type B freeboards shall be in compliance with regulation 6 to regulation 7-3;* or

.2 the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code);* or

.3 the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code);* or

.4 the damage stability requirements of regulation 27 of the 1966 Load Lines Convention as applied in compliance with resolutions A.320(IX) and A.514(13), provided that in the case of cargo ships to which regulation 27(9) applies, main transverse watertight bulkheads, to be considered effective, are spaced according to paragraph (12)(f) of resolution A.320(1X), except that ships intended for the carriage of deck cargo shall be in compliance with regulation 6 to regulation 7-3; or

.5 the damage stability requirements of regulation 27 of the 1988 Load Lines Protocol, except that ships intended for the carriage of deck cargo shall be in compliance with regulation 6 to regulation 7-3; or

.6 the subdivision and damage stability standards in other instrumentst developed by the Organization .

.2 Unless expressly provided otherwise, the requirements in parts B-2 and B-4 shall apply to cargo ships.

3 The Administration may, for a particular ship or group of ships, accept alternative methodologies if it is satisfied that at least the same degree of safety as represented by these regulations is achieved.

• Refer to Guidelines for verification of damage stability requirements for tankers (MSC.1/Circ.1461). t .1 For offshore supply vessels of not more than 100 m in length (L), the Guidelines for the design and construction of offshore supply vessels, 2006 (resolution MSC.235(82), as amended by resolution MSC.335(90)); or

.2 For special purpose ships, the Code of Safety for Special Purpose Ships, 2008 (resolution MSC.266(84) and Corr.1), as amended (2008 SPS Code).

Part B Subdivision and stability

Any Administration which allows such alternative methodologies shall communicate to the Organization particulars thereof.

4 Ships shall be as efficiently subdivided as is possible having regard to the nature of the service for which they are intended. The degree of subdivision shall vary with the subdivision length (Ls) of the ship and with the service, in such manner that the highest degree of subdivision corresponds with the ships of greatest subdivision length (Ls), primarily engaged in the carriage of passengers.

5 Where it is proposed to fit decks, inner skins or longitudinal bulkheads of sufficient tightness to seriously restrict the flow of water, the Administration shall be satisfied that proper consideration is given to beneficial or adverse effects of such structures in the calculations.

Stability

Regulation 5

Intact stability

1 Every passenger ship, regardless of size, and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion. The lightship displacement and the longitudinal, transverse and vertical position of its centre of gravity shall be determined. In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards shall as a minimum comply with the requirements of part A of the 2008 IS Code.

2 The Administration may allow the inclining test of an individual cargo ship to be dispensed with, provided basic stability data are available from the inclining test of a sister ship and it is shown to the satisfaction of the Administration that reliable stability information for the exempted ship can be obtained from such basic data, as required by regulation 5-1. A lightweight survey shall be carried out upon completion and the ship shall be inclined whenever, in comparison with the data derived from the sister ship, a deviation from the lightship displacement exceeding 1% for ships of 160 m or more in length and 2% for ships of 50 m or less in length and as determined by linear interpolation for intermediate lengths or a deviation from the lightship longitudinal centre of gravity exceeding 0.5% of L is found.

3 The Administration may also allow the inclining test of an individual ship or class of ships especially designed for the carriage of liquids or ore in bulk to be dispensed with when reference to existing data for similar ships clearly indicates that, due to the ship's proportions and arrangements, more than sufficient metacentric height will be available in all probable loading conditions.

4 Where any alterations are made to a ship so as to materially affect the stability information supplied to the master, amended stability information shall be provided. If necessary, the ship shall be re-inclined. The ship shall be re-inclined if anticipated deviations exceed one of the values specified in paragraph 5.* SEE INTERPRETATION 23

5 At periodical intervals not exceeding 5 years, a lightweight survey shall be carried out on all passenger ships to verify any changes in lightship displacement and longitudinal centre of gravity. The ship shall be re-inclined whenever, in comparison with the approved stability information, a deviation from the lightship displacement exceeding 2% or a deviation of the longitudinal centre of gravity exceeding 1% of Lis found or anticipated.

SEE INTERPRETATION 23

6 Every ship shall have scales of draughts marked clearly at the bow and stern. In the case where the draught marks are not located where they are easily readable, or operational constraints for a particular trade make it difficult to read the draught marks, then the ship shall also be fitted with a reliable draught indicating system by which the bow and stern draughts can be determined.

* Refer to Revised explanatory notes to the SOLAS chapter /1-1 subdivision and damage stability regulations (resolution MSC.429(98)/Rev.2).

Part B-1 Stability

Regulation 5-1

Stability information to be supplied to the master* SEE INTERPRETATION 24

1 The master shall be supplied with such information to the satisfaction of the Administration as is necessary to enable him by rapid and simple processes to obtain accurate guidance as to the stability of the ship under varying conditions of service. A copy of the stability information shall be furnished to the Administration.

2 The information should include:

.1 curves or tables of minimum operational metacentric height (GM) and maximum permissible trim versus draught which assures compliance with the intact and damage stability requirements where applicable, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) and maximum permissible trim versus draught, or with the equivalents of either of these curves or tables;

.2 instructions concerning the operation of cross-flooding arrangements; and

.3 all other data and aids which might be necessary to maintain the required intact stability and stability after damage.

3 The intact and damage stability information required by regulation 5-1.2 shall be presented as consolidated data and encompass the full operating range of draught and trim.t Applied trim values shall coincide in all stability information intended for use on board. Information not required for determination of stability and trim limits should be excluded from this information.

4 If the damage stability is calculated in accordance with regulation 6 to regulation 7-3 and, if applicable, with regulations 8 and 9.8, a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts d 5, dP and d 1. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. When it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM.

5 As an alternative to a single envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed at each subdivision draught. The lowest values of each partial index A 5, AP and A 1 across these trims shall then be used in the summation of the attained subdivision index A according to regulation 7.1. This will result in one GM limit curve based on the GM used at each draught. A trim limit diagram showing the assumed trim range shall be developed.

6 When curves or tables of minimum operational metacentric height (GM) or maximum allowable KG versus draught are not provided, the master shall ensure that the operating condition does not deviate from approved loading conditions, or verify by calculation that the stability requirements are satisfied for this loading condition.

Regulation 6

Required subdivision index R+

1 The subdivision of a ship is considered sufficient if the attained subdivision index A, determined in accordance with regulation 7, is not less than the required subdivision index R calculated in accordance with

• Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456) and the Revised guidance to the master for avoiding dangerous situations in adverse weather and sea conditions (MSC.1/Circ.1228). t Refer to Guidelines for verification of damage stability requirements for tankers (MSC.1/Circ.1461). *The Maritime Safety Committee, in adopting the regulations contained in parts B to B-4, invited Administrations to note that the regulations should be applied in conjunction with the explanatory notes developed by the Organization in order to ensure their uniform application.

this regulation and if, in addition, the partial indices As, AP and A1 are not less than 0.9R for passenger ships and O.SR for cargo ships.

2 For ships to which the damage stability requirements of this part apply, the degree of subdivision to be provided shall be determined by the required subdivision index R, as follows:

.1 In the case of cargo ships greater than 100 m in length (Ls):

128 R = 1 - Ls+ 152

.2 In the case of cargo ships not less than 80 m in length (Ls) and not greater than 100 m in length (Ls):

1 R=1- L R

1 + 1do x 1 - 0 R where R0 is the value Ras calculated in accordance with the formula in sub-paragraph .1 .

.3 In the case of passenger ships:

Persons on board R N < 400 R = 0.722

400 ::::; N :::; 1,350 N + 0.66923 R = 7 580 ' 1,350 < N:::; 6,000 R = 0.0369 x In (N + 89.048) + 0.579 N > 6,000 R=1- 852 .5 + 0.03875 x N N + 5,000 where: N = total number of persons on board.

Regulation 7

Attained subdivision index A

1 An attained subdivision index A is obtained by the summation of the partial indices As, Ap and A1, weighted as shown and calculated for the draughts ds, dP and d 1 defined in regulation 2 in accordance with the following formula:

A = 0.4As + 0.4AP + 0.2A1

Each partial index is a summation of contributions from all damage cases taken in consideration, using the following formula:

A=~ Pi Sj Where: i represents each compartment or group of compartments under consideration, Pi accounts for the probability that only the compartment or group of compartments under consideration may be flooded, disregarding any horizontal subdivision, as defined in regulation 7-1, si accounts for the probability of survivalafter flooding the compartment or group of compartments under consideration, and includes the effect of any horizontal subdivision, as defined in regulation 7-2.

2 As a minimum, the calculation of A shall be carried out at the level trim for the deepest subdivision draught ds and the partial subdivision draught dP. The estimated service trim may be used for the light service draught dI. If, in any anticipated service condition within the draught range from ds to dI, the trim variation in comparison with the calculated trims is greater than 0.5% of L, one or more additional calculations of A are to be performed for the same draughts but including sufficient trims to ensure that, for all intended service conditions, the difference in trim in comparison with the reference trim used for one calculation will be not more than 0.5% of L. Each additional calculation of A shall comply with regulation 6.1.

3 When determining the positive righting lever (GZ) of the residual stability curve in the intermediate and final equilibrium stages of flooding, the displacement used should be that of the intact loading condition. All calculations should be done with the ship freely trimming.

4 The summation indicated by the above formula shall be taken over the ship's subdivision length (Ls) for all cases of flooding in which a single compartment or two or more adjacent compartments are involved. In the case of unsymmetrical arrangements, the calculated A value should be the mean value obtained from calculations involving both sides. Alternatively, it should be taken as that corresponding to the side which evidently gives the least favourable result.

5 Wherever wing compartments are fitted, contribution to the summation indicated by the formula shall be taken for all cases of flooding in which wing compartments are involved. Additionally, cases of simultaneous flooding of a wing compartment or group of compartments and the adjacent inboard compartment or group of compartments, but excluding damage of transverse extent greater than one half of the ship breadth B, may be added. For the purpose of this regulation, transverse extent is measured inboard from ship's side, at right angle to the centreline at the level of the deepest subdivision draught.

6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.

7 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed flooded. However, the Administration may permit minor progressive flooding if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.

Regulation 7-1

Calculation of the factor Pi

1 The factor Pi for a compartment or group of compartments shall be calculated in accordance with paragraphs 1.1 and 1.2 using the following notations:

j the aftmost damage zone number involved in the damage starting with No. 1 at the stern;

n the number of adjacent damage zones involved in the damage;

k the number of a particular longitudinal bulkhead as barrier for transverse penetration in a damage zone counted from shell towards the centreline. The shell has k = O;

x1 the distance from the aft terminal of Ls to the aft end of the zone in question;

x2 the distance from the aft terminal of Ls to the forward end of the zone in question;

b the mean transverse distance in metres measured at right angles to the centreline at the deepest subdivision draught between the shell and an assumed vertical plane extended between the longitudinal limits used in calculating the factor Pi and which is a tangent to, or common with, all or part of the outermost portion of the longitudinal bulkhead under consideration. This vertical plane shall be so orientated that the mean transverse distance to the shell is a maximum, but not more than twice the least distance between the plane and the shell. If the upper part of a longitudinal bulkhead is below the deepest subdivision draught the vertical plane used for determination of b is assumed to extend upwards to the deepest subdivision waterline. In any case, b is not to be taken as greater than B/2.

If the damage involves a single zone only: Pi = p(x\, x2) • [r(xlj, x2j, bk) - r(xli' x2i1 bk_1)]

If the damage involves two adjacent zones: Pi= p(x\, x2j+1) • [r(x\, x2j+1, bk) - r(xlj, x2j+1, bk-1)1 - p(xlj, x2) • [r(xlj, x2j, bk) - r(xlj, x2j, bk-1)1 - p(x1j+1, x2j+1) • [r(x1j+1, x2j+1, bk) - r(xlj+l, x2j+1, bk-1)]

If the damage involves three or more adjacent zones: Pi= p(x\, x2j+n-1) • [r(x\, x2j+n-1, bk) - r(x\, x2j+n-1, bk-1)1 - p(x\, x2j+n-2) • [r(x\, x2j+n-2, bk) - r(xlj, x2j+n-2, bk_1)] - p(xlj+l, x2j+n-1) • [r(xlj+l, x2j+n-l, bk) - r(xlj+l, x2j+n-l, bk_1)] + p(x\+1, x2j+n-2) • [r(x\+1, x2j+n-2, bk) - r(x\+1, x2j+n-2, bk-1)1 and where r(xl, x2, b 0 ) = 0.

1.1 The factor p(xl, x2) is to be calculated according to the following formulae:

Overall normalized max damage length: lmax = 10/33 Knuckle point in the distribution: /kn = 5/33 Cumulative probability at lkn: Pk= 11 / 12 Maximum absolute damage length: lm ax = 60 m Length where normalized distribution ends: L* = 260 m Probability density at/ = 0:

bo = 2 (pk - 1 - Pk ) /kn /max - /kn

When Ls::; L*:

Jm = m•1n(jmax, T /max )

/m 1 - ✓ 1 + (1 - 2pk)bol m + ~ ba2Jm2 Jk= T+ b 0 b12 =bo

When Ls> L*: • (JmaXly Jm * = mln fm ax )

The non-dimensional damage length: I= (x2 - x1) Ls The normalized length of a compartment or group of compartments: In is to be taken as the lesser of I and Im

1.1.1 Where neither limit of the compartment or group of compartments under consideration coincides with the aft or forward terminals:

I::; lk: p(x1, x2) = p 1 = t; J2(b 11 1 + 3h 12 ) I> lk: p(x1, x2) = P2 = - fb 11I/ + ½(b 11I - b 12 )1/ + b 12J/k - fb 21 Un 3 - I/) + ½(b2,J - b 22 )Un2 - J/) + b22IUn -lk)

1.1.2 Where the aft limit of the compartment or group of compartments under consideration coincides with the aft terminal or the forward limit of the compartment or group of compartments under consideration coincides with the forward terminal:

1::;lk: p(x1, x2) = ½(p 1 + /)

l>k p(x1, x2) = ½(p 2 + I)

1.1.3 Where the compartment or groups of compartments considered extends over the entire subdivision length (Ls): p(x1, x2) = 1

1.2 The factor r(x1, x2, b) shall be determined by the following formulae:

r(x1, x2, b) = 1 - (1 - C) • ( 1 - p(xf x2))

where:

C = 12 • lb • (-45 ·lb+ 4), where b lb= 15 · B

1.2.1 Where the compartment or groups of compartments considered extends over the entire subdivision length (L 5):

G = G1 = ½ b11lb2 + b1)b

1.2.2 Where neither limit of the compartment or group of compartments under consideration coincides with the aft or forward terminals:

G = G2 = -fb11lo3 + ½(b11 I - b12l 102 + b12J/o, where

10 = min(/, lb)

1.2.3 Where the aft limit of the compartment or group of compartments under consideration coincides with the aft terminal or the forward limit of the compartment or group of compartments under consideration coincides with the forward terminal: 1 G = 2 (G2 + G1 • I)

Regulation 7-2

Calculation of the factor si SEE INTERPRETATION 25

1 The factors; shall be determined for each case of assumed flooding, involving a compartment or group of compartments, in accordance with the following notations and the provisions in this regulation. 0e is the equilibrium heel angle in any stage of flooding, in degrees; 0v is the angle, in any stage of flooding, where the righting lever becomes negative, or the angle at which an opening incapable of being closed weathertight becomes submerged; GZmax is the maximum positive righting lever, in metres, up to the angle 0v; Range is the range of positive righting levers, in degrees, measured from the angle 0e. The positive range is to be taken up to the angle 0v; Flooding stage is any discrete step during the flooding process, including the stage before equalization (if any), until final equilibrium has been reached.

1.1 The factors;, for any damage case at any initial loading condition, d;, shall be obtained from the formula:

S; = minimum (sintermediate,i or Sfinal,i . Smom,;) where:

sintermediate,i is the probability to survive all intermediate flooding stages until the final equilibrium stage, and is calculated in accordance with paragraph 2;

Sfinal,i is the probability to survive in the final equilibrium stage of flooding. It is calculated in accordance with paragraph 3; Smom,i is the probability to survive heeling moments, and is calculated in accordance with paragraph 4.

2 For passenger ships, and cargo ships fitted with cross-flooding devices, the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows: GZmax Range )¼ Sintermediate,i = ( 0.05 • - 7 - where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15° for passenger ships and 30° for cargo ships.

For cargo ships not fitted with cross-flooding devices the factor sintermediate,i is taken as unity, except if the Administration considers that the stability in intermediate stages of flooding may be insufficient, it should require further investigation thereof. For passenger and cargo ships, where cross-flooding devices are fitted, the time for equalization shall not exceed 10 min.

3 1. shall be obtained from the formula:

The factor sf.ma,,

5 = K . ( GZmax . Range )¼ final,i TGZmax TRange where: GZmax is not to be taken as more than TGZmax; Range is not to be taken as more than TRange; TGZmax 0.20 m, for ro-ro passenger ships each damage case that involves a ro-ro space, TGZmax = 0.12 m, otherwise;

TRange = 20°, for ro-ro passenger ships each damage case that involves a ro-ro space, TRange = 16°, otherwise; K = 1 if 0e ::::; 0min, K = 0 if 0e 2: 0max,

0 -0 K= max e otherwise emax - emin ' where: 0min is 7° for passenger ships and 25° for cargo ships; and 0max is 15° for passenger ships and 30° for cargo ships.

4 The factor Smom,i is applicable only to passenger ships (for cargo ships Smom,i shall be taken as unity) and shall be calculated at the final equilibrium from the formula: (GZmax - 0.04) • Displacement where: Displacement is the intact displacement at the respective draught (d 5 , dp or d 1); Mheel is the maximum assumed heeling moment as calculated in accordance with paragraph 4.1; and 5mom,i ::::; l

4.1 The heeling moment Mheel is to be calculated as follows:

Mheel = maximum ( Mpassenger or M wind or M surviva lcraft )

4.1.1 Mpassenger is the maximum assumed heeling moment resulting from movement of passengers, and is to be obtained as follows: Mpassenger = (0.075 • Np) • (0.45 • B) (t • m)

where: NP is the maximum number of passengers permitted to be on board in the service condition corresponding to the deepest subdivision draught under consideration; and B is the breadth of the ship as defined in regulation 2.8. Alternatively, the heeling moment may be calculated assuming the passengers are distributed with 4 persons per square metre on available deck areas towards one side of the ship on the decks where muster stations are located and in such a way that they produce the most adverse heeling moment. In doing so, a weight of 75 kg per passenger is to be assumed.

4.1.2 Mwind is the maximum assumed wind moment acting in a damage situation:

(P ·A· Z) Mwind = g 806 (t • m) I

where: P = 120 N/m 2 ; A = projected lateral area above waterline; Z = distance from centre of lateral projected area above waterline to T/2; and T = respective draught (d5, dp or d1).

4.1.3 Msurvivalcraft is the maximum assumed heeling moment due to the launching of all fully loaded davit- launched survival craft on one side of the ship. It shall be calculated using the following assumptions:

.1 all lifeboats and rescue boats fitted on the side to which the ship has heeled after having sustained damage shall be assumed to be swung out fully loaded and ready for lowering;

.2 for lifeboats which are arranged to be launched fully loaded from the stowed position, the maximum heeling moment during launching shall be taken;

.3 a fully loaded davit-launched liferaft attached to each davit on the side to which the ship has heeled after having sustained damage shall be assumed to be swung out ready for lowering;

.4 persons not in the life-saving appliances which are swung out shall not provide either additional heeling or righting moment; and

.5 life-saving appliances on the side of the ship opposite to the side to which the ship has heeled shall be assumed to be in a stowed position.

5 Unsymmetrical flooding is to be kept to a minimum consistent with the efficient arrangements. Where it is necessary to correct large angles of heel, the means adopted shall, where practicable, be self-acting, but in any case where controls to equalization devices are provided they shall be operable from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. These fittings together with their controls shall be acceptable to the Administration.* Suitable information concerning the use of equalization devices shall be supplied to the master of the ship.

5.1 Tanks and compartments taking part in such equalization shall be fitted with air pipes or equivalent means of sufficient cross-section to ensure that the flow of water into the equalization compartments is not delayed.

5.2 The factors; is to be taken as zero in those cases where the final waterline, taking into account sinkage, heel and trim, immerses:

.1 for cargo ships, the lower edge of openings through which progressive flooding may take place and such flooding is not accounted for in the calcu lation of factor s;. Such openings shall include air pipes, ventilators and openings which are closed by means of weathertight doors or hatch covers;

.2 any part of the bulkhead deck in passenger ships considered a horizontal evacuation route for compliance with chapter 11-2; and

.3 for passenger ships subject to the provIsIons of regulation 1.1.1.1 and constructed before

1 January 2024, the lower edge of openings through which progressive flooding may take place and such flooding is not accounted for in the calculation of factors;. Such openings shall include air pipes, ventilators and openings which are closed by means of weathertight doors or hatch covers.

5.3 The factor S; is to be taken as zero if, taking into account sinkage, heel and trim, any of the following occur in any intermediate stage or in the final stage of flooding:

.1 immersion of any vertical escape hatch in the bulkhead deck of passenger ships and the freeboard deck of cargo ships intended for compliance with chapter 11-2;

.2 any controls intended for the operation of watertight doors, equalization devices, valves on piping or on ventilation ducts intended to maintain the integrity of watertight bulkheads from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships become inaccessible or inoperable;

.3 immersion of any part of piping or ventilation ducts located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded; and

.4 for passenger ships constructed on or after 1 January 2024, immersion of the lower edge of openings through which progressive flooding may take place and such flooding is not accounted for in the calculation of factor S;. Such openings shall include air pipes, ventilators and openings which are closed by means of weathertight doors or hatch covers.

* Reference is made to the Revised recommendation on a standard method for evaluating cross-flooding arrangements (resolution MSC.362(92), as may be amended).

5.4 However, where compartments assumed flooded due to progressive flooding are taken into account in the damage stability calculations, multiple values of sintermediate,i may be calculated, assuming equalization in additional flooding phases.

5.5 Except as provided in paragraph 5.3.1, openings closed by means of watertight manhole covers and flush scuttles, remotely operated sliding watertight doors, side scuttles of the non-opening type as well as watertight access doors and watertight hatch covers required to be kept closed during navigation in accordance with regulations 22 to 24 need not be considered.

6 Where horizontal watertight boundaries are fitted above the waterline under consideration, the s-value calculated for the lower compartment or group of compartments shall be obtained by multiplying the value as determined in paragraph 1.1 by the reduction factor Vm according to paragraph 6.1, which represents the probability that the spaces above the horizontal subdivision will not be flooded.

6.1 The factor vm shall be obtained from the formula:

Vm = v(Hj,n,m, d) - v(Hj,n,m-1, d)

where:

Hj,n,m is the least height above the baseline, in metres, within the longitudinal range of x 1(jl ... x2(j+n-,l of the m th horizontal boundary which is assumed to limit the vertical extent of flooding for the damaged compartments under consideration;

Hj,n,m-l is the least height above the baseline, in metres, within the longitudinal range of x 1(jl ... x2(j+n-,) of the (m-1) th horizontal boundary which is assumed to limit the vertical extent of flooding for the damaged compartments under consideration;

j signifies the aft terminal of the damaged compartments under consideration; m represents each horizontal boundary counted upwards from the waterline under consideration; dis the draught in question as defined in regulation 2; and

x1 and x2 represent the terminals of the compartment or group of compartments considered in regulation 7-1.

6.1.1 The factors v(Hj,n,m, d) and v(Hj,n,m-l, d) shall be obtained from the formulae:

v(H, d) = 0.8 (H7~ d), if (Hm- d) is less than, or equal to, 7.8 m;

v(H, d) = 0.8 + 0.2( (H - :.~- 7•8 ) in all other cases,

where

v(Hj,n,m, d) is to be taken as 1, if Hm coincides with the uppermost watertight boundary of the ship within the range (x1vi ... x2(j+n-1i), and

v(Hj,n,o, d) is to be taken as 0.

In no case is Vm to be taken as less than zero or more than 1.

6.2 In general, each contribution dA to the index A in the case of horizontal subdivisions is obtained from the formula:

dA = P; • [v1 • 5min1 + (v2 - V1) • 5min2 + .. • + (1 - Vm-1) • Sminml where:

vm = the v-value calculated in accordance with paragraph 6.1;

smin = the least s-factor for all combinations of damages obtained when the assumed damage extends from the assumed damage height Hm downwards.

Regulation 7-3

Permeability

1 For the purpose of the subdivision and damage stability calculations of the regulations, the permeability of each general compartment or part of a compartment shall be as follows:

Spaces Permeability Appropriated to stores 0.60 Occupied by accommodation 0.95 Occupied by machinery 0.85 Void spaces 0.95 Intended for liquids 0 or 0_95a

a Whichever results in the more severe requirement.

2 For the purpose of the subdivision and damage stability calculations of the regulations, the permeability of each cargo compartment or part of a compartment shall be as follows:

Permeability Permeability Permeability Spaces at draught d, at draught dp at draught d1 Dry cargo spaces 0.70 0.80 0.95 Container spaces 0.70 0.80 0.95 - ,,. ,, Ro-ro spaces 0.90 0.90 0.95 ·- Cargo liquids 0.70 0.80 0.95

3 Other figures for permeability may be used if substantiated by calculations.

Regulation 8

Special requirements concerning passenger ship stability

1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that s; = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions used to calculate the attained subdivision index A. If the attained subdivision index A is calculated for different trims, this requirement shall also be satisfied for those loading conditions.

2 A passenger ship intended to carry 36 or more persons is to be capable of withstanding damage along the side shell to an extent specified in paragraph 3. Compliance with this regulation is to be achieved by demonstrating that s;, as defined in regulation 7-2, is not less than 0.9 for the three loading conditions used to calculate the attained subdivision index A. If the attained subdivision index A is calculated for different trims, this requirement shall also be satisfied for those loading conditions.

3 The damage extent* to be assumed when demonstrating compliance with paragraph 2 is to be dependent on the total number of persons carried, and L, such that:

.1 the vertical extent of damage is to extend from the ship's moulded baseline to a position up to

12.5 m above the position of the deepest subdivision draught as defined in regulation 2, unless a lesser vertical extent of damage were to give a lower value of s;, in which case this reduced extent is to be used;

* Refer to the appendix of the Revised guidance for watertight doors on passenger ships which may be opened during navigation (MSC.1/Circ.1564).

.2 where 400 or more persons are to be carried, a damage length of 0.03L, but not less than 3 m is to be assumed at any position along the side shell, in conjunction with a penetration inboard of 0.18 but not less than 0.75 m measured inboard from the ship side, at right angles to the centreline at the level of the deepest subdivision draught;

.3 where fewer than 400 persons are carried, damage length is to be assumed at any position along the shell side between transverse watertight bulkheads provided that the distance between two adjacent transverse watertight bulkheads is not less than the assumed damage length. If the distance between adjacent transverse watertight bulkheads is less than the assumed damage length, only one of these bulkheads shall be considered effective for the purpose of demonstrating compliance with paragraph 2;

.4 where 36 persons are carried, a damage length of 0.015L but not less than 3 m is to be assumed, in conjunction with a penetration inboard of 0.05B but not less than 0.75 m; and

.5 where more than 36, but fewer than 400, persons are carried, the values of damage length and penetration inboard, used in the determination of the assumed extent of damage, are to be obtained by linear interpolation between the values of damage length and penetration which apply for ships carrying 36 persons and 400 persons as specified in sub-paragraphs .4 and .2.

Regulation 8-1

System capabilities and operational information after a flooding casualty on passenger ships

1 Application Passenger ships having length, as defined in regulation 11-1/2.5, of 120 m or more or having three or more main vertical zones shall comply with the provisions of this regulation.

2 Availability of essential systems in case of flooding damage* A passenger ship shall be designed so that the systems specified in regulation 11-2/21.4 remain operational when the ship is subject to flooding of any single watertight compartment.

3 Operational information after a flooding casualty

3.1 For the purpose of providing operational information to the master for safe return to port after a flooding casualty, passenger ships, as specified in paragraph 1, shall have:

.1 an onboard stability computer; or

.2 shore-based support, based on the guidelines developed by the Organization.t

3.2 Passenger ships constructed before 1 January 2014 shall comply with the provisions in paragraph 3.1 not later than the first renewal survey after 1 January 2025.

• Refer to the Interim Explanatory Notes for the assessment of passenger ship systems' capabilities after a fire or flooding casualty (MSC.1/Circ.1369 and MSC.1/Circ.1369/Add.1). t Refer to the Guidelines on operational information for masters of passenger ships for safe return to port by own power or under tow (MSC.1/Circ.1400) for ships constructed on or after 1 January 2014 but before 13 May 2016, or the Revised guidelines on operational information for masters of passenger ships for safe return to port (MSC.1/Circ.1532/Rev.1) for ships constructed on or after 13 May 2016, or the Guidelines on operational information for masters in case of flooding for passenger ships constructed before 1 January 2014 (MSC.1/Circ.1589).

Subdivision, watertight and weathertight integrity

Regulation 9

Double bottoms in passenger ships and cargo ships other than tankers

1 A double bottom shall be fitted extending from the collision bulkhead to the afterpeak bulkhead, as far as this is practicable and compatible with the design and proper working of the ship.

2 Where a double bottom is required to be fitted, the inner bottom shall be continued out to the ship's sides in such a manner as to protect the bottom to the turn of the bilge. Such protection will be deemed satisfactory if the inner bottom is not lower at any part than a plane parallel with the keel line and which is located not less than a vertical distance h measured from the keel line, as calculated by the formula: h = B/20 However, in no case is the value of h to be less than 760 mm, and need not be taken as more than 2,000 mm.

3.1 Small wells constructed in the double bottom in connection with drainage arrangements shall not extend downward more than necessary. The vertical distance from the bottom of such a well to a plane coinciding with the keel line shall not be less than h/2 or 500 mm, whi chever is greater, or compliance with paragraph 8 of this regulation shall be shown for that part of the ship.

3.2 Other wells (e.g. for lubricating oil under main engines) may be permitted by the Administration if satisfied that the arrangements give protection equivalent to that afforded by a double bottom complying with this regulation.

3.2.1 For a cargo ship of 80 m in length and upwards or for a passenger ship, proof of equivalent protection is to be shown by demonstrating that the ship is capable of withstanding bottom damages as specified in paragraph 8. Alternatively, wells for lubricating oil below main engines may protrude into the double bottom below the boundary line defined by the distance h provided that the vertical distance between the well bottom and a plane coinciding with the keel line is not less than h/2 or 500 mm, whichever is greater.

3.2.2 For cargo ships of less than 80 m in length the arrangements shall provide a level of safety to the satisfaction of the Administration.

4 A double bottom need not be fitted in way of watertight tanks, including dry tanks of moderate size, provided the safety of the ship is not impaired in the event of bottom or side damage.

5 In the case of passenger ships to which the provisions of regulation 1.5 apply and which are engaged on regular service within the limits of a short international voyage as defined in regulation 111/3.22, the Administration may permit a double bottom to be dispensed with if satisfied that the fitting of a double bottom in that part would not be compatible with the design and proper working of the ship.

6 Any part of a cargo ship of 80 m in length and upwards or of a passenger ship that is not fitted with a double bottom in accordance with paragraphs 1, 4 or 5, as specified in paragraph 2, shall be capable of withstanding bottom damages, as specified in paragraph 8, in that part of the ship. For cargo ships of less than 80 m in length the alternative arrangements shall provide a level of safety to the satisfaction of the Administration.

Part 8-2 Subdivision, watertight and weathertight integrity

7 In the case of unusual bottom arrangements in a cargo ship of 80 m in length and upwards or a passenger ship, it shall be demonstrated that the ship is capable of withstanding bottom damages as specified in paragraph 8. For cargo ships of less than 80 m in length the alternative arrangements shall provide a level of safety to the satisfaction of the Administration.

8 Compliance with paragraphs 3.1, 3.2.1, 6 or 7 is to be achieved by demonstrating that si, when calculated in accordance with regulation 7-2, is not less than 1 for all service conditions when subject to bottom damage with an extent specified in sub-paragraph .2 below for any position in the affected part of the ship:

.1 Flooding of such spaces shall not render emergency power and lighting, internal communication, signals or other emergency devices inoperable in other parts of the ship .

.2 Assumed extent of damage shall be as follows:

For 0.3L from the forward Any other part of the ship perpendicular of the ship Longitudinal extent 1/3L 213 or 14.5 m, whichever is less 1/3L213 or 14.5 m, whichever is less Transverse extent B/6 or 10 m, whichever is less B/6 or 5 m, whichever is less Vertical extent, measured B/20, to be taken as not less than 0.76 m B/20, to be taken as not less than 0.76 m from the keel line and not more than 2 m and not more than 2 m

.3 If any damage of a lesser extent than the maximum damage specified in .2 would result in a more severe condition, such damage should be considered.

9 In case of large lower holds in passenger ships, the Administration may require an increased double- bottom height of not more than B/10 or 3 m, whichever is less, measured from the keel line. Alternatively, bottom damages may be calculated for these areas, in accordance with paragraph 8, but assuming an increased vertical extent.

Regulation 10

Construction of watertight bulkheads

1 Each watertight subdivision bulkhead, whether transverse or longitudinal, shall be constructed having scantlings as specified in regulation 2.17. In all cases, watertight subdivision bulkheads shall be capable of supporting at least the pressure due to a head of water up to the bulkhead deck of passenger ships and the freeboard deck of cargo ships.

2 Steps and recesses in watertight bulkheads shall be as strong as the bulkhead at the place where each occurs.

Regulation 11

Initial testing of watertight bulkheads, etc.

1 Testing watertight spaces not intended to hold liquids and cargo holds intended to hold ballast by filling them with water is not compulsory. When testing by filling with water is not carried out, a hose test shall be carried out where practicable. This test shall be carried out in the most advanced stage of the fitting out of the ship. Where a hose test is not practicable because of possible damage to machinery, electrical equipment insulation or outfitting items, it may be replaced by a careful visual examination of welded connections, supported where deemed necessary by means such as a dye penetrant test or an ultrasonic leak test or an equivalent test. In any case a thorough inspection of the watertight bulkheads shall be carried out.

2 The forepeak, double bottom (including duct keels) and inner skins shall be tested with water to a head corresponding to the requirements of regulation 10.1.

3 Tanks which are intended to hold liquids, and which form part of the watertight subdivision of the ship, shall be tested for tightness and structural strength with water to a head corresponding to its design pressure.

The water head is in no case to be less than the top of the air pipes or to a level of 2.4 m above the top of the tank, whichever is the greater.

4 The tests referred to in paragraphs 2 and 3 are for the purpose of ensuring that the subdivision structural arrangements are watertight and are not to be regarded as a test of the fitness of any compartment for the storage of oil fuel or for other special purposes for which a test of a superior character may be required, depending on the height to which the liquid has access in the tank or its connections.

Regulation 12

Peak and machinery space bulkheads, shaft tunnels, etc.

1 A collision bulkhead shall be fitted which shall be watertight up to the bulkhead deck of passenger ships and the freeboard deck of cargo ships. This bulkhead shall be located at a distance from the forward perpendicular of not less than 0.0SL or 10 m, whichever is less, and, except as may be permitted by the Administration, not more than 0.08L or 0.0SL + 3 m, whichever is the greater.

2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 at the deepest subdivision draught loading condition, level trim or any forward trim loading conditions, if any part of the ship forward of the collision bulkhead is flooded without vertical limits.

3 Where any part of the ship below the waterline extends forward of the forward perpendicular, e.g. a bulbous bow, the distances stipulated in paragraph 1 shall be measured from a point either:

.1 at the mid-length of such extension;

.2 at a distance 0.015L forward of the forward perpendicular; or

.3 at a distance 3 m forward of the forward perpendicular, whichever gives the smallest measurement.

4 The bulkhead may have steps or recesses provided they are within the limits prescribed in paragraph 1 or 3.

5 No doors, manholes, access openings, ventilation ducts or any other openings shall be fitted in the collision bulkhead below the bulkhead deck of passenger ships and the freeboard deck of cargo ships.

6.1 For ships subject to the provisions of regulation 1.1.1.1 and constructed before 1 January 2024, except as provided in paragraph 6.3, the collision bulkhead may be pierced below the bulkhead deck of passenger ships and the freeboard deck of cargo ships by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a screw-down valve capable of being operated from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships, the valve being located inside the forepeak at the collision bulkhead. The Administration may, however, authorize the fitting of this valve on the after side of the collision bulkhead provided that the valve is readily accessible under all service conditions and the space in which it is located is not a cargo space. Alternatively, for cargo ships, the pipe may be fitted with a butterfly valve suitably supported by a seat or flanges and capable of being operated from above the freeboard deck. All valves shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable.

6.2 For ships constructed on or after 1 January 2024, except as provided in paragraph 6.3, the collision bulkhead may be pierced below the bulkhead deck of passenger ships and the freeboard deck of cargo ships by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a remotely controlled valve capable of being operated from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. The valve shall be normally closed. If the remote control system should fail during operation of the valve, the valve shall close automatically or be capable of being closed manually from a position above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. The valve shall be located at the collision bulkhead on either the forward or aft side, provided the space on the aft side is not a cargo space. The valve shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable.

6.3 If the forepeak is divided to hold two different kinds of liquids, the Administration may allow the collision bulkhead to be pierced below the bulkhead deck of passenger ships and the freeboard deck of cargo ships by two pipes, each of which is fitted as required by paragraph 6.1 or 6.2, provided the Administration is satisfied that there is no practical alternative to the fitting of such a second pipe and that, having regard to the additional subdivision provided in the forepeak, the safety of the ship is maintained.

7 Where a long forward superstructure is fitted, the collision bulkhead shall be extended weathertight to the deck next above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. The extension need not be fitted directly above the bulkhead below provided that all parts of the extension, including any part of the ramp attached to it, are located within the limits prescribed in paragraph 1 or 3, with the exception permitted by paragraph 8, and that the part of the deck which forms the step is made effectively weathertight. The extension shall be so arranged as to preclude the possibility of the bow door or ramp, where fitted, causing damage to it in the case of damage to, or detachment of, a bow door or any part of the ramp.

8 Where bow doors are fitted and a sloping loading ramp forms part of the extension of the collision bulkhead above the bulkhead deck of passenger ships and the freeboard deck of cargo ships, the ramp shall be weathertight over its complete length. In cargo ships, the part of the ramp which is more than 2.3 m above the freeboard deck may extend forward of the limit specified in paragraph 1 or 3. Ramps not meeting the above requirements shall be disregarded as an extension of the collision bulkhead.

9 The number of openings in the extension of the collision bulkhead above the freeboard deck shall be restricted to the minimum compatible with the design and normal operation of the ship. All such openings shall be capable of being closed weathertight.

10 Bulkheads shall be fitted separating the machinery space from cargo and accommodation spaces forward and aft and made watertight up to the bulkhead deck of passenger ships and the freeboard deck of cargo ships. An afterpeak bulkhead shall also be fitted and made watertight up to the bulkhead deck or the freeboard deck. The afterpeak bulkhead may, however, be stepped below the bulkhead deck or the freeboard deck, provided the degree of safety of the ship as regards subdivision is not thereby diminished.

11 In all cases stern tubes shall be enclosed in watertight spaces of moderate volume. In passenger ships the stern gland shall be situated in a watertight shaft tunnel or other watertight space separate from the stern tube compartment and of such volume that, if flooded by leakage through the stern gland, the bulkhead deck will not be immersed. In cargo ships other measures to minimize the danger of water penetrating into the ship in case of damage to stern tube arrangements may be taken at the discretion of the Administration.

Regulation 13

Openings in watertight boundaries below the bulkhead deck in passenger ships SEE INTERPRETATION 26

1 The number of openings in watertight boundaries shall be reduced to the minimum compatible with the design and proper working of the ship; satisfactory means shall be provided for closing these openings.

2.1 Where pipes, scuppers, electric cables, etc., are carried through watertight boundaries, arrangements shall be made to ensure the watertight integrity of the boundaries.

2.2 Valves not forming part of a piping system shall not be permitted in watertight boundaries.

2.3 Lead or other heat-sensitive materials shall not be used in systems which penetrate watertight boundaries, where deterioration of such systems in the event of fire would impair the watertight integrity of the boundaries.

SEE INTERPRETATION 27

3 No doors, manholes or access openings are permitted in watertight transverse bulkheads dividing a cargo space from an adjoining cargo space, except as provided in paragraph 8.1 and in regulation 14.

4 Subject to paragraph 9, not more than one door, apart from the doors to shaft tunnels, may be fitted in each watertight bulkhead within spaces containing the main and auxiliary propulsion machinery, including boilers serving the needs of propulsion. Where two or more shafts are fitted, the tunnels shall be connected by an intercommunicating passage. There shall be only one door between the machinery space and the tunnel spaces where two shafts are fitted and only two doors where there are more than two shafts. All these doors shall be of the sliding type and shall be so located as to have their sills as high as practicable. The hand gear for operating these doors from above the bulkhead deck shall be situated outside the spaces containing the machinery.

5.1 Watertight doors, except as provided in paragraph 8.1 or regulation 14, shall be power-operated sliding doors complying with the requirements of paragraph 6.

5.2 The means of operation, whether by power or by hand, of any power-operated sliding watertight door shall be capable of closing the door with the ship listed to 15° either way. Consideration shall also be given to the forces which may act on either side of the door as may be experienced when water is flowing through the opening, applying a static head equivalent to a water height of at least 1 m above the sill on the centreline of the door.

5.3 Watertight door controls, including hydraulic piping and electric cables, shall be kept as close as practicable to the bulkhead in which the doors are fitted, in order to minimize the likelihood of them being involved in any damage which the ship may sustain. The positioning of watertight doors and their controls shall be such that if the ship sustains damage within one fifth of the breadth of the ship, as defined in regulation 2, such distance being measured at right angles to the centreline at the level of the deepest subdivision draught, the operation of the watertight doors clear of the damaged portion of the ship is not impaired.

6.1 Each power-operated sliding watertight door:

.1 shall have a vertical or horizontal motion;

.2 shall, subject to paragraph 9, be normally limited to a maximum clear opening width of 1.2 m. The Administration may permit larger doors only to the extent considered necessary for the effective operation of the ship provided that other safety measures, including the following, are taken into consideration:

.1 special consideration shall be given to the strength of the door and its closing appliances in order to prevent leakages; and

.2 the door shall be located inboard the damage zone B/5;

.3 shall be fitted with the necessary equipment to open and close the door using electric power, hydraulic power or any other form of power that is acceptable to the Administration;

.4 shall be provided with an individual hand-operated mechanism. It shall be possible to open and close the door by hand at the door itself from either side, and in addition, close the door from an accessible position above the bulkhead deck with an all-round crank motion or some other movement providing the same degree of safety acceptable to the Administration. Direction of rotation or other movement is to be clearly indicated at all operating positions. The time necessary for the complete closure of the door, when operating by hand gear, shall not exceed 90 s with the ship in the upright position. Visual indicators to show whether the door is open or closed shall be provided at the accessible position above the bulkhead deck;

.5 shall be provided with controls for opening and closing the door by power from both sides of the door and also for closing the door by power from the central operating console(s) required by paragraph 7.1;

.6 shall be provided with an audible alarm, distinct from any other alarm in the area, which will sound whenever the door is closed remotely by power and which shall sound for at least 5 s but no more than 10 s before the door begins to move and shall continue sounding until the door is completely closed. In the case of remote hand operation it is sufficient for the audible alarm to sound only when the door is moving. Additionally, in passenger areas and areas of high ambient noise the Administration may require the audible alarm to be supplemented by an intermittent visual signal at the door; and

.7 shall have an approximately uniform rate of closure under power. The closure time, from the time the door begins to move to the time it reaches the completely closed position, shall in no case be less than 20 s or more than 40 s with the ship in the upright position.

6.2 The electrical power required for power-operated sliding watertight doors shall be supplied from the emergency switchboard either directly or by a dedicated distribution board situated above the bulkhead deck. The associated control, indication and alarm circuits shall be supplied from the emergency switchboard either directly or by a dedicated distribution board situated above the bulkhead deck and be capable of being automatically supplied by the transitional source of emergency electrical power required by regulation 42.3.1.3 in the event of failure of either the main or emergency source of electrical power.

6.3 Power-operated sliding watertight doors shall have either:

.1 a centralized hydraulic system with two independent power sources each consisting of a motor and pump capable of simultaneously closing all doors. In addition, there shall be for the whole installation hydraulic accumulators of sufficient capacity to operate all the doors at least three times, i.e. closed-open-closed, against an adverse list of 15°. This operating cycle shall be capable of being carried out when the accumulator is at the pump cut-in pressure. The fluid used shall be chosen considering the temperatures liable to be encountered by the installation during its service. The power-operating system shall be designed to minimize the possibility of having a single failure in the hydraulic piping adversely affect the operation of more than one door. The hydraulic system shall be provided with a low-level alarm for hydraulic fluid reservoirs serving the power-operated system and a low gas pressure alarm or other effective means of monitoring loss of stored energy in hydraulic accumulators. These alarms are to be audible and visual and shall be situated on the central operating console(s) required by paragraph 7.1; or

.2 an independent hydraulic system for each door with each power source consisting of a motor and pump capable of opening and closing the door. In addition, there shall be a hydraulic accumulator of sufficient capacity to operate the door at least three times, i.e. closed-open-closed, against an adverse list of 15°. This operating cycle shall be capable of being carried out when the accumulator is at the pump cut-in pressure. The fluid used shall be chosen considering the temperatures liable to be encountered by the installation during its service. A low gas pressure group alarm or other effective means of monitoring loss of stored energy in hydraulic accumulators shall be provided at the central operating console(s) required by paragraph 7.1. Loss of stored energy indication at each local operating position shall also be provided; or

.3 an independent electrical system and motor for each door with each power source consisting of a motor capable of opening and closing the door. The power source shall be capable of being automatically supplied by the transitional source of emergency electrical power as required by regulation 42.4.2 in the event of failure of either the main or emergency source of electrical power and with sufficient capacity to operate the door at least three times, i.e. closed-open-closed, against an adverse list of 15°.

For the systems specified in paragraphs 6.3.1, 6.3.2 and 6.3.3, provision should be made as follows: Power systems for power-operated sliding watertight doors shall be separate from any other power system. A single failure in the electric or hydraulic power-operated systems excluding the hydraulic actuator shall not prevent the hand operation of any door.

6.4 Control handles shall be provided at each side of the bulkhead at a minimum height of 1.6 m above the floor and shall be so arranged as to enable persons passing through the doorway to hold both handles in the open position without being able to set the power closing mechanism in operation accidentally. The direction of movement of the handles in opening and closing the door shall be in the direction of door movement and shall be clearly indicated.

6.5 As far as practicable, electrical equipment and components for watertight doors shall be situated above the bulkhead deck and outside hazardous areas and spaces.

6.6 The enclosures of electrical components necessarily situated below the bulkhead deck shall provide suitable protection against the ingress of water.*

6.7 Electric power, control, indication and alarm circuits shall be protected against fault in such a way that a failure in one door circuit will not cause a failure in any other door circuit. Short circuits or other faults in the alarm or indicator circuits of a door shall not result in a loss of power operation of that door. Arrangements shall be such that leakage of water into the electrical equipment located below the bulkhead deck will not cause the door to open.

6.8 A single electrical failure in the power operating or control system of a power-operated sliding watertight door shall not result in a closed door opening. Availability of the power supply should be continuously monitored at a point in the electrical circuit as near as practicable to each of the motors required by paragraph 6.3. Loss of any such power supply should activate an audible and visual alarm at the central operating console(s) required by paragraph 7.1.

7.1 A central operating console for all power-operated sliding watertight doors shall be located in the safety centre in accordance with regulation 11-2/23. If the safety centre is located in a separate space adjacent to the navigation bridge, a central operating console shall also be located on the navigation bridge. The central operating console(s) shall have a "master mode" switch with two modes of control: a "local control" mode, which shall allow any door to be locally opened and locally closed after use without automatic closure, and a "doors closed" mode, which shall automatically close any door that is open in not more than 60 s with the ship in an upright position. The "doors closed" mode shall permit doors to be opened locally and shall automatically re-close the doors upon release of the local control mechanism. The "master mode" switch shall normally be in the "local control" mode. The "doors closed" mode shall only be used in an emergency or for testing purposes.

7.2 For ships subject to the provisions of regulation 1.1.1.1 and constructed before 1 January 2024, the central operating console at the navigation bridge shall be provided with a diagram showing the location of each door, with visual indicators to show whether each door is open or closed. A red light shall indicate a door is fully open and a green light shall indicate a door is fully closed. When the door is closed remotely the red light shall indicate the intermediate position by flashing. The indicating circuit shall be independent of the control circuit for each door.

7.3 For ships constructed on or after 1 January 2024, the central operating console(s) shall be provided with a diagram showing the location of each power-operated sliding watertight door, with visual indicators to show whether each door is open or closed. A red light shall indicate a door is fully open and a green light shall indicate a door is fully closed. When the door is closed remotely the red light shall indicate the intermediate position by flashing. The indicating circuit shall be independent of the control circuit for each door. Indication shall also be provided to the onboard stability computer, if installed in accordance with regulation 11-1/8-1.3.1.

7.4 It shall not be possible to remotely open any door from the central operating console.

8.1 If the Administration is satisfied that such doors are essential, watertight doors of satisfactory construction may be fitted in watertight bulkheads dividing cargo spaces on 'tween-decks. Such doors may be hinged, rolling or sliding doors but shall not be remotely controlled. They shall be fitted at the highest level and as far from the shell plating as practicable, but in no case shall the outboard vertical edges be situated at a distance

* Refer to the following publication IEC 60529:2003:

.1 electrical motors, associated circuits and control components; protected to IPX 7 standard;

.2 door position indicators and associated circuit components; protected to IPX 8 standard; and

.3 door movement warning signals; protected to IPX 6 standard.

Other arrangements for the enclosures of electrical components may be fitted provided the Administration is satisfied that an equivalent protection is achieved. The water pressure IPX 8 shall be based on the pressure that may occur at the location of the component during flooding for a period of 36 h.

from the shell plating which is less than one fifth of the breadth of the ship, as defined in regulation 2, such distance being measured at right angles to the centreline at the level of the deepest subdivision draught.

8.2 Should any such doors be accessible during the voyage, they shall be fitted with a device which prevents unauthorized opening. When it is proposed to fit such doors, the number and arrangements shall receive the special consideration of the Administration.

9 Portable plates on bulkheads shall not be permitted except in machinery spaces. The Administration may permit not more than one power-operated sliding watertight door larger than those specified in paragraph

6.1.2 to be substituted for these portable plates in each watertight bulkhead, provided these doors are intended to remain closed during navigation except in case of urgent necessity at the discretion of the master. These doors need not meet the requirements of paragraph 6.1 .4 regarding complete closure by hand-operated gear in 90 s.

10.1 Where trunkways or tunnels for access from crew accommodation to the machinery spaces, for piping or for any other purpose, are carried through watertight bulkheads, they shall be watertight and in accordance with the requirements of regulation 16-1. The access to at least one end of each such tunnel or trunkway, if used as a passage at sea, shall be through a trunk extending watertight to a height sufficient to permit access above the bulkhead deck. The access to the other end of the trunkway or tunnel may be through a watertight door. Such trunkways or tunnels shall not extend through the first subdivision bulkhead abaft the collision bulkhead.

10.2 Where it is proposed to fit tunnels piercing watertight bulkheads, these shall receive the special consideration of the Administration.

10.3 Where trunkways in connection with refrigerated cargo and ventilation or forced draught trunks are carried through more than one watertight bulkhead, the means of closure at such openings shall be operated by power and be capable of being closed from a central position situated above the bulkhead deck.

Regulation 13-1

Openings in watertight bulkheads and internal decks in cargo ships SEE INTERPRETATION 26

1 The number of openings in watertight subdivisions is to be kept to a minimum compatible with the design and proper working of the ship. Where penetrations of watertight bulkheads and internal decks are necessary for access, piping, ventilation, electrical cables, etc., arrangements are to be made to maintain the watertight integrity. The Administration may permit relaxation in the watertightness of openings above the freeboard deck, provided that it is demonstrated that any progressive flooding can be easily controlled and that the safety of the ship is not impaired.

2 Doors provided to ensure the watertight integrity of internal openings which are used while at sea are to be sliding watertight doors capable of being remotely closed from the bridge and are also to be operable locally from each side of the bulkhead. Indicators are to be provided at the control position showing whether the doors are open or closed, and an audible alarm is to be provided at the door closure. The power, control and indicators are to be operable in the event of main power failure. Particular attention is to be paid to minimizing the effect of control system failure. Each power-operated sliding watertight door shall be provided with an individual hand-operated mechanism. It shall be possible to open and close the door by hand at the door itself from both sides.

3 Access doors and access hatch covers normally closed at sea, intended to ensure the watertight integrity of internal openings, shall be provided with means of indication locally and on the bridge showing whether these doors or hatch covers are open or closed. A notice is to be affixed to each such door or hatch cover to the effect that it is not to be left open.

4 Watertight doors or ramps of satisfactory construction may be fitted to internally subdivide large cargo spaces, provided that the Administration is satisfied that such doors or ramps are essential. These doors or ramps may be hinged, rolling or sliding doors or ramps, but shall not be remotely controlled. Should any of the doors or ramps be accessible during the voyage, they shall be fitted with a device which prevents unauthorized opening.

5 Other closing appliances which are kept permanently closed at sea to ensure the watertight integrity of internal openings shall be provided with a notice which is to be affixed to each such closing appliance to the effect that it is to be kept closed. Manholes fitted with closely bolted covers need not be so marked.

Regulation 14

Passenger ships carrying goods vehicles and accompanying personnel

1 This regulation applies to passenger ships designed or adapted for the carriage of goods vehicles and accompanying personnel.

2 If in such a ship the total number of passengers, which includes personnel accompanying vehicles, does not exceed 12 + Ai25, where Ad= total deck area (square metres) of spaces available for the stowage of goods vehicles and where the clear height at the stowage position and at the entrance to such spaces is not less than

4 m, the provisions of regulations 13.8.1 and 13.8.2 in respect of watertight doors apply except that the doors may be fitted at any level in watertight bulkheads dividing cargo spaces. Additionally, indicators are required on the navigation bridge to show automatically when each door is closed and all door fastenings are secured.

3 The ship may not be certified for a higher number of passengers than assumed in paragraph 2, if a watertight door has been fitted in accordance with this regulation.

Regulation 15

Openings in the shell plating below the bulkhead deck of passenger ships and the freeboard deck of cargo ships

1 The number of openings in the shell plating shall be reduced to the minimum compatible with the design and proper working of the ship.

2 The arrangement and efficiency of the means for closing any opening in the shell plating shall be consistent with its intended purpose and the position in which it is fitted and generally to the satisfaction of the Administration.

3.1 Subject to the requirements of the International Convention on Load Lines in force, no sidescuttle shall be fitted in such a position that its sill is below a line drawn parallel to the bulkhead deck at side and having its lowest point 2.5% of the breadth of the ship above the deepest subdivision draught, or 500 mm, whichever is the greater.

3.2 All sidescuttles the sills of which are below the bulkhead deck of passenger ships and the freeboard deck of cargo ships, as permitted by paragraph 3.1, shall be of such construction as will effectively prevent any person opening them without the consent of the master of the ship.

4 Efficient hinged inside deadlights, so arranged that they can be easily and effectively closed and secured watertight, shall be fitted to all sidescuttles except that, abaft one eighth of the ship's length from the forward perpendicular and above a line drawn parallel to the bulkhead deck at side and having its lowest point at a height of 3.7 m plus 2.5% of the breadth of the ship above the deepest subdivision draught, the deadlights may be portable in passenger accommodation, unless the deadlights are required by the International Convention on Load Lines in force to be permanently attached in their proper positions. Such portable deadlights shall be stowed adjacent to the sidescuttles they serve.

5.1 No sidescuttles shall be fitted in any spaces which are appropriated exclusively to the carriage of cargo.

5.2 Sidescuttles may, however, be fitted in spaces appropriated alternatively to the carriage of cargo or passengers, but they shall be of such construction as will effectively prevent any person opening them or their dead lights without the consent of the master.

6 Automatic ventilating sidescuttles shall not be fitted in the shell plating below the bulkhead deck of passenger ships and the freeboard deck of cargo ships without the special sanction of the Administration.

7 The number of scuppers, sanitary discharges and other similar openings in the shell plating shall be reduced to the minimum either by making each discharge serve for as many as possible of the sanitary and other pipes or in any other satisfactory manner.

8.1 All inlets and discharges in the shell plating shall be fitted with efficient and accessible arrangements for preventing the accidental admission of water into the ship.

8.2.1 Subject to the requirements of the International Convention on Load Lines in force, and except as provided in paragraph 8.3, each separate discharge led through the shell plating from spaces below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be provided with either one automatic non-return valve fitted with a positive means of closing it from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships or with two automatic non-return valves without positive means of closing, provided that the inboard valve is situated above the deepest subdivision draught and is always accessible for examination under service conditions. Where a valve with positive means of closing is fitted, the operating position above the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall always be readily accessible and means shall be provided for indicating whether the valve is open or closed.

8.2.2 The requirements of the International Convention on Load Lines in force shall apply to discharges led through the shell plating from spaces above the bulkhead deck of passenger ships and the freeboard deck of cargo ships.

8.3 Machinery space, main and auxiliary sea inlets and discharges in connection with the operation of machinery shall be fitted with readily accessible valves between the pipes and the shell plating or between the pipes and fabricated boxes attached to the shell plating. In manned machinery spaces the valves may be controlled locally and shall be provided with indicators showing whether they are open or closed.

8.4 Moving parts penetrating the shell plating below the deepest subdivision draught shall be fitted with a watertight sealing arrangement acceptable to the Administration. The inboard gland shall be located within a watertight space of such volume that, if flooded, the bulkhead deck of passenger ships and the freeboard deck of cargo ships will not be submerged. The Administration may require that if such compartment is flooded, essential or emergency power and lighting, internal communication, signals or other emergency devices must remain available in other parts of the ship.

8.5 All shell fittings and valves required by this regulation shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable. All pipes to which this regulation refers shall be of steel or other equivalent material to the satisfaction of the Administration.

9 For ships subject to the provisions of regulation 1.1.1.1 and constructed before 1 January 2024, gangway, cargo and fuelling ports fitted below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be watertight and in no case be so fitted as to have their lowest point below the deepest subdivision draught.

10 For ships constructed on or after 1 January 2024, cargo ports and other similar openings (e.g. gangway and fuelling ports) in the side of ships below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be fitted with doors so designed as to ensure the same watertightness and structural integrity as the surrounding shell plating. Unless otherwise granted by the Administration, these openings shall open outwards. The number of such openings shall be the minimum compatible with the design and proper working of the ship. In no case shall these openings be so fitted as to have their lowest point below the deepest subdivision draught.

Regulation 15-1

External openings in cargo ships SEE INTERPRETATION 26

1 All external openings leading to compartments assumed intact in the damage analysis, which are below the final damage waterline, are required to be watertight.

2 External openings required to be watertight in accordance with paragraph 1 shall, except for cargo hatch covers, be fitted with indicators on the bridge.

3 Openings in the shell plating below the deck limiting the vertical extent of damage shall be fitted with a device that prevents unauthorized opening if they are accessible during the voyage.

4 Other closing appliances which are kept permanently closed at sea to ensure the watertight integrity of external openings shall be provided with a notice affixed to each appliance to the effect that it is to be kept closed. Manholes fitted with closely bolted covers need not be so marked.

Regulation 16

Construction and initial tests of watertight closures

1.1 The design, materials and construction of all watertight closures such as doors, hatches, sidescuttles, gangway and cargo ports, valves and pipes referred to in these regulations shall be to the satisfaction of the Administration.

1.2 Such valves, doors, hatches and mechanisms shall be su itably marked to ensure that they may be properly used to provide maximum safety.

1.3 The frames of vertical watertight doors shall have no groove at the bottom in which dirt might lodge and prevent the door closing properly.

2 Watertight doors and hatches shall be tested by water pressure to the maximum head of water they might sustain in a final or intermediate stage of flooding. For cargo ships not covered by damage stability requirements, watertight doors and hatches shall be tested by water pressure to a head of water measured from the lower edge of the opening to 1 m above the freeboard deck. Where testing of individual doors and hatches is not carried out because of possible damage to insulation or outfitting items, testing of individual doors and hatches may be replaced by a prototype pressure test of each type and size of door or hatch with a test pressure corresponding at least to the head required for the individual location. The prototype test shall be carried out before the door or hatch is fitted. The installation method and procedure for fitting the door or hatch on board shall correspond to that of the prototype test. When fitted on board, each door or hatch shall be checked for proper seating between the bulkhead, the frame and the door or between deck, the coaming and the hatch.

Regulation 16-1

Construction and initial tests of watertight decks, trunks, etc.

1 Watertight decks, trunks, tunnels, duct keels and ventilators shall be of the same strength as watertight bulkheads at corresponding levels. The means used for making them watertight, and the arrangements adopted for closing openings in them, shall be to the satisfaction of the Administration. Watertight ventilators and trunks shall be carried at least up to the bulkhead deck in passenger ships and up to the freeboard deck in cargo ships.

2 In passenger ships, where a ventilation trunk passing through a structure penetrates a watertight area of the bulkhead deck, the trunk shall be capable of withstanding the water pressure that may be present within the trunk, after having taken into account the maximum heel angle during flooding, in accordance with regulation 7-2.

3 In ro-ro passenger ships, where all or part of the penetration of the bulkhead deck is on the main ro-ro deck, the trunk shall be capable of withstanding impact pressure due to internal water motions (sloshing) of water trapped on the ro-ro deck.

4 After completion, a hose or flooding test shall be applied to watertight decks and a hose test to watertight trunks, tunnels and ventilators.

Regulation 17

Internal watertight integrity of passenger ships above the bulkhead deck SEE INTERPRETATION 26

1 For passenger ships subject to the provisions of regulation 1.1.1.1 and constructed before 1 January 2024, the Administration may require that all reasonable and practicable measures shall be taken to limit the entry and spread of water above the bulkhead deck. Such measures may include partial bulkheads or webs. When partial watertight bulkheads and webs are fitted on the bulkhead deck, above or in the immediate vicinity of watertight bulkheads, they shall have watertight shell and bulkhead deck connections so as to restrict the flow of water along the deck when the ship is in a heeled damaged condition. Where the partial watertight bulkhead does not line up with the bulkhead below, the bulkhead deck between shall be made effectively watertight. Where openings, pipes, scuppers, electric cables, etc. are carried through the partial watertight bulkheads or decks within the immersed part of the bulkhead deck, arrangements shall be made to ensure the watertight integrity of the structure above the bulkhead deck.*

2 For ships constructed on or after 1 January 2024, the internal watertight subdivision arrangements to limit the entry and spread of water above the bulkhead deck shall be in accordance with the design arrangements necessary for compliance with the stability requirements in part B-1 , and part B-2 if applicable. Where pipes, scuppers, electric cables, etc. are carried through internal watertight boundaries that are immersed at any intermediate or final stage of flooding in damage cases that contribute to the attained subdivision index A, arrangements shall be made to ensure their watertight integrity.

3 For ships constructed on or after 1 January 2024, doors in internal watertight subdivision arrangements above the bulkhead deck, and also above the worst intermediate or final stage of flooding waterlines, shall be capable of preventing the passage of water when immersed in the required range of positive stability for any damage cases contributing to the attained subdivision index A. These doors may remain open provided they can be remotely closed from the navigation bridge. They shall always be ready to be immediately closed.

4 All openings in the exposed weather deck shall have coamings of ample height and strength and shall be provided with efficient means for expeditiously closing them weathertight. Freeing ports, open rails and scuppers shall be fitted as necessary for rapidly clearing the weather deck of water under all weather conditions.

5 Air pipes terminating within a superstructure which are not fitted with watertight means of closure shall be considered as unprotected openings when applying regulation 7-2.6.1.1.

6 Sidescuttles, gangway, cargo and fuelling ports and other means for closing openings in the shell plating above the bulkhead deck shall be of efficient design and construction and of sufficient strength having regard to the spaces in which they are fitted and their positions relative to the deepest subdivision draught.t

7 Efficient inside deadlights, so arranged that they can be easily and effectively closed and secured watertight, shall be provided for all sidescuttles to spaces below the first deck above the bulkhead deck.

• Refer to Guidance notes on the integrity of flooding boundaries above the bulkhead deck of passenger ships for proper application of regulations /1-1/8 and 20, paragraph 1, of SOLAS 1974, as amended (MSC/Circ.541, as may be amended). t Refer to Strength and securing and locking arrangements of shell doors on ro-ro passenger ships (resolution A.793(19)).

Regulation 17-1

Integrity of the hull and superstructure, damage prevention and control on ro-ro passenger ships SEE INTERPRETATION 26

1.1 All access from the ro-ro deck that leads to spaces below the bulkhead deck shall have a lowest point which is not less than 2.5 m above the bulkhead deck, unless the access is covered by the provisions of paragraphs 1.2 or 1.3.

SEE INTERPRETATION 28

1.2 Where vehicle ramps are installed to give access to spaces below the bulkhead deck, their openings shall be able to be closed weathertight to prevent ingress of water below and fitted with alarms and open/ close indicators on the navigation bridge. The means of closure shall be watertight if the deck is intended as a watertight horizontal boundary under regulation 7-2.6.

1.3 Subject to regulations 23.3 and 23.6, the Administration may permit the fitting of particular accesses to spaces below the bulkhead deck provided they are necessary for the essential working of the ship, e.g. the movement of machinery and stores, and subject to such accesses being made watertight, fitted with alarms and open/close indicators on the navigation bridge.

2 Indicators shall be provided on the navigation bridge for all shell doors, loading doors and other closing appliances which, if left open or not properly secured, could, in the opinion of the Administration, lead to flooding of a special category space or ro-ro space. The indicator system shall be designed on the fail-safe principle and shall show by visual alarms if the door is not fully closed or if any of the securing arrangements are not in place and fully locked and by audible alarms if such door or closing appliances become open or the securing arrangements become unsecured. The indicator panel on the navigation bridge shall be equipped with a mode selection function " harbour/sea voyage" so arranged that an audible alarm is given on the navigation bridge if the ship leaves harbour with the bow doors, inner doors, stern ramp or any other side shell doors not closed or any closing device not in the correct position. The power supply for the indicator system shall be independent of the power supply for operating and securing the doors.

3 Television surveillance and a water leakage detection system shall be arranged to provide an indication to the navigation bridge and to the engine control station of any leakage through inner and outer bow doors, stern doors or any other shell doors which could lead to flooding of special category spaces or ro-ro spaces.

Subdivision load line assignment for passenger ships

Regulation 18

Assigning, marking and recording of subdivision load lines for passenger ships

1 In order that the required degree of subdivision shall be maintained, a load line corresponding to the approved subdivision draught shall be assigned and marked on the ship's sides. A ship intended for alternating modes of operation may, if the owners desire, have one or more additional load lines assigned and marked to correspond with the subdivision draughts which the Administration may approve for the alternative service configurations. Each service configuration so approved shall comply with part B-1 of this chapter independently of the results obtained for other modes of operation.

2 The subdivision load lines assigned and marked shall be recorded in the Passenger Ship Safety Certificate, and shall be distinguished by the notation P1 for the principal passenger service configuration, and P2, P3, etc., for the alternative configurations. The principal passenger configuration shall be taken as the mode of operation in which the required subdivision index R will have the highest value.

3 The freeboard corresponding to each of these load lines shall be measured at the same position and from the same deck line as the freeboards determined in accordance with the International Convention on Load Lines in force.

4 The freeboard corresponding to each approved subdivision load line and the service configuration for which it is approved shall be clearly indicated on the Passenger Ship Safety Certificate.

5 In no case shall any subdivision load line mark be placed above the deepest load line in salt water as determined by the strength of the ship or the International Convention on Load Lines in force.

6 Whatever may be the position of the subdivision load line marks, a ship shall in no case be loaded so as to submerge the load line mark appropriate to the season and locality as determined in accordance with the International Convention on Load Lines in force.

7 A ship shall in no case be so loaded that when it is in salt water the subdivision load line mark appropriate to the particular voyage and service configuration is submerged.

Stability management

Regulation 19

Damage control information*

1 There shall be permanently exhibited, or readily available on the navigation bridge, for the guidance of the officer in charge of the ship, plans showing clearly for each deck and hold the boundaries of the watertight compartments, the openings therein with the means of closure and position of any controls thereof, and the arrangements for the correction of any list due to flooding. In addition, booklets containing the aforementioned information shall be made avai lable to the officers of the ship.

2 General precautions to be included shall consist of a listing of equipment, conditions and operational procedures considered by the Administration to be necessary to maintain watertight integrity under normal ship operations.

3 Specific precautions to be included shall consist of a listing of elements (i.e. closures, security of cargo, sounding of alarms, etc.) considered by the Administration to be vital to the survival of the ship, passengers and crew.

4 In case of ships to which damage stability requirements of part B-1 apply, damage stability information shall provide the master with a simple and easily understandable way of assessing the ship's survivability in all damage cases involving a compartment or group of compartments.

5 For passenger ships constructed on or after 1 January 2024, and to which regulation 8-1.3 applies, the damage control information shall include a reference to activation of damage stability support from the onboard stability computer, if installed, and to shore-based support when provided.

Regulation 19-1

Damage control drills for passenger ships

1 This regulation applies to passenger ships constructed before, on or after 1 January 2020.

2 A damage control drill shall take place at least every three months. The entire crew need not participate in every drill, but only those crew members with damage control responsibilities.

3 The damage control drill scenarios shall vary each drill so that emergency conditions are simulated for different damage conditions and shall, as far as practicable, be conducted as if there were an actual emergency.

4 Each damage control drill shall include:

.1 for crew members with damage control responsibilities, reporting to stations and preparing for the duties described in the muster list required by regulation 111/8;

.2 use of the damage control information and the onboard damage stability computer, if fitted, to conduct stability assessments for the simulated damage conditions;

* Refer to Guidelines for damage control plans and information to the master (MSC.1/Circ.1245, as amended by MSC.1/Circ.1570) and to the Guidelines for verification of damage stability requirements for tankers (MSC.1/Circ.1461).

Part B-4 Stability management

.3 establishment of the communications link between the ship and shore-based support, if provided;

.4 operation of watertight doors and other watertight closures;

.5 demonstrating proficiency in the use of the flooding detection system, if fitted, in accordance with muster list duties;

.6 demonstrating proficiency in the use of cross-flooding and equalization systems, if fitted, in accordance with muster list duties;

.7 operation of bilge pumps and checking of bilge alarms and automatic bilge pump starting systems;

and

.8 instruction in damage survey and use of the ship's damage control systems.

5 At least one damage control drill each year shall include activation of the shore-based support, if provided in compliance with regulation 11-1/8-1.3, to conduct stability assessments for the simulated damage conditions.

6 Every crew member with assigned damage control responsibilities shall be familiarized with their duties and about the damage control information before the voyage begins.

7 A record of each damage control drill shall be maintained in the same manner as prescribed for the other drills in regulation 111/ 19.5.

Regulation 20

Loading of ships

1 On completion of loading of the ship and prior to its departure, the master shall determine the ship's trim and stability and also ascertain and record that the ship is upright and in compliance with stability criteria in relevant regulations. The determination of the ship's stability shall always be made by calculation or by ensuring that the ship is loaded according to one of the precalculated loading conditions within the approved stability information. The Administration may accept the use of an electronic loading and stability computer or equivalent means for this purpose.

2 Water ballast should not in general be carried in tanks intended for oil fuel. In ships in which it is not practicable to avoid putting water in oil fuel tanks, oily-water separating equipment to the satisfaction of the Administration shall be fitted, or other alternative means, such as discharge to shore facilities, acceptable to the Administration shall be provided for disposing of the oily-water ballast.

3 The provisions of this regulation are without prejudice to the provisions of the International Convention for the Prevention of Pollution from Ships in force.

Regulation 21

Periodical operation and inspection of watertight doors, etc., in passenger ships

1 Operational tests of watertight doors, sidescuttles, valves and closing mechanisms of scuppers shall take place weekly. In ships in which the voyage exceeds one week in duration, a complete set of operational tests shall be held before the voyage commences, and others thereafter at least once a week during the voyage.

2 All watertight doors, both hinged and power-operated, in watertight bulkheads, in use at sea, shall be operated daily.

3 The watertight doors and all mechanisms and indicators connected therewith, all valves the closing of which is necessary to make a compartment watertight, and all valves the operation of which is necessary for damage control cross-connections shall be periodically inspected at sea at least once a week.

4 A record of all operational tests and inspections required by this regulation shall be recorded in the logbook with an explicit record of any defects which may be disclosed.

Regulation 22

Prevention and control of water ingress, etc. SEE INTERPRETATION 26

1 All watertight doors shall be kept closed during navigation except that they may be opened during navigation as specified in paragraph 3. Watertight doors of a width of more than 1.2 m in machinery spaces as permitted by regulation 13.9 may only be opened in the circumstances detailed in that regulation. Any door which is opened in accordance with this paragraph shall be ready to be immediately closed.

2 Watertight doors located below the bulkhead deck of passenger ships and the freeboard deck of cargo ships having a maximum clear opening width of more than 1.2 m shall be kept closed during navigation, except for limited periods when absolutely necessary as determined by the Administration.

3 A watertight door may be opened during navigation to permit the passage of passengers or crew, or when work in the immediate vicinity of the door necessitates it being opened. The door must be immediately closed when transit through the door is complete or when the task which necessitated it being open is finished. The Administration shall authorize that such a watertight door may be opened during navigation only after careful consideration of the impact on ship operations and survivability taking into account guidance issued by the Organization.* A watertight door permitted to be opened during navigation shall be clearly indicated in the ship's stability information and shall always be ready to be immediately closed.

4 Portable plates on bulkheads shall always be in place before the voyage commences and shall not be removed during navigation except in case of urgent necessity at the discretion of the master. The necessary precautions shall be taken in replacing them to ensure that the joints are watertight. Power-operated sliding watertight doors permitted in machinery spaces in accordance with regulation 13.9 shall be closed before the voyage commences and shall remain closed during navigation except in case of urgent necessity at the discretion of the master.

5 Watertight doors fitted in watertight bulkheads dividing cargo spaces on 'tween-decks in accordance with regulation 13.8.1 shall be closed before the voyage commences and shall be kept closed during navigation. The time at which such doors are opened or closed shall be recorded in such logbook as may be prescribed by the Administration.

6 For ships subject to the provisions of regulation 1.1.1.1 and constructed before 1 January 2024, gangway, cargo and fuelling ports fitted below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be effectively closed and secured watertight before the voyage commences, and shall be kept closed during navigation.

7 For ships constructed on or after 1 January 2024, gangway, cargo and fuelling ports fitted below the bulkhead deck of passenger ships and the freeboard deck of cargo ships and all watertight hatches shall be effectively closed and secured watertight before the voyage commences, and shall be kept closed during navigation. However, the master may permit a watertight hatch to be opened during navigation for a limited period of time sufficient to permit passage or for access. It shall then be closed.

8 The following doors, located above the bulkhead deck of passenger ships and the freeboard deck of cargo ships, shall be closed and locked before the voyage commences and shall remain closed and locked until the ship is at its next berth:

.1 cargo loading doors in the shell or the boundaries of enclosed superstructures;

.2 bow visors fitted in positions as indicated in paragraph 8.1;

.3 cargo loading doors in the collision bulkhead; and

.4 ramps forming an alternative closure to those defined in paragraphs 8.1 to 8.3 inclusive.

* Refer to the Revised guidance for watertight doors on passenger ships which may be opened during navigation (MSC.1/Circ.1564).

9 Where a door cannot be opened or closed while the ship is at the berth, such a door may be opened or left open while the ship approaches or draws away from the berth, but only so far as may be necessary to enable the door to be immediately operated. In any case, the inner bow door must be kept closed.

10 Notwithstanding the requirements of paragraphs 8.1 and 8.4, the Administration may authorize that particular doors can be opened at the discretion of the master, if necessary for the operation of the ship or the embarking and disembarking of passengers when the ship is at safe anchorage and provided that the safety of the ship is not impaired.

11 The master shall ensure that an effective system of supervision and reporting of the closing and opening of the doors referred to in paragraph 8 is implemented.

12 The master shall ensure, before any voyage commences, that an entry in such logbook as may be prescribed by the Administration is made of the time the doors specified in paragraph 13 are closed and the time at which particular doors are opened in accordance with paragraph 14.

13 Hinged doors, portable plates, sidescuttles, gangway, cargo and bunkering ports and other openings, which are required by these regulations to be kept closed during navigation, shall be closed before the voyage commences. The time at which such doors are opened and closed (if permissible under these regulations) shall be recorded in such logbook as may be prescribed by the Administration.

14 Where in a between-deck, the sills of any of the sidescuttles referred to in regulation 15.3.2 are below a line drawn parallel to the bulkhead deck at side of passenger ships and the freeboard deck at side of cargo ships, and having its lowest point 1.4 m plus 2.5% of the breadth of the ship above the water when the voyage commences, all the sidescuttles in that between-deck shall be closed watertight and locked before the voyage commences, and they shall not be opened before the ship arrives at the next port. In the application of this paragraph the appropriate allowance for fresh water may be made when applicable .

.1 The time at which such sidescuttles are opened in port and closed and locked before the voyage commences shall be recorded in such logbook as may be prescribed by the Administration .

.2 For any ship that has one or more sidescuttles so placed that the requirements of paragraph 14 would apply when it was floating at its deepest subdivision draught, the Administration may indicate the limiting mean draught at which these sidescuttles will have their sills above the line drawn parallel to the bulkhead deck at side of passenger ships and the freeboard deck at side of cargo ships, and having its lowest point 1.4 m plus 2.5% of the breadth of the ship above the waterline corresponding to the limiting mean draught, and at which it will therefore be permissible for the voyage to commence without them being closed and locked and to be opened during navigation on the responsibility of the master. In tropical zones as defined in the International Convention on Load Lines, 1966, this limiting draught may be increased by 0.3 m.

15 Sidescuttles and their deadlights which will not be accessible during navigation shall be closed and secured before the voyage commences.

16 If cargo is carried in spaces referred to in regulation 15.5.2, the sidescuttles and their deadlights shall be closed watertight and locked before the cargo is shipped and the time at which such scuttles and deadlights are closed and locked shall be recorded in such logbook as may be prescribed by the Administration.

Regulation 22-1

Flooding detection systems for passenger ships carrying 36 or more persons SEE INTERPRETATION 29

A flooding detection system for watertight spaces below the bulkhead deck shall be provided based on the guidelines developed by the Organization.*

* Refer to Guidelines for flooding detection systems on passenger ships (MSC.1/Circ.1291).

Regulation 23

Special requirements for ro-ro passenger ships

1 Special category spaces and ro-ro spaces shall be continuously patrolled or monitored by effective means, such as television surveillance, so that any movement of vehicles in adverse weather conditions and unauthorized access by passengers thereto can be detected during navigation.

2 Documented operating procedures for closing and securing all shell doors, loading doors and other closing appliances which, if left open or not properly secured, could, in the opinion of the Administration, lead to flooding of a special category space or ro-ro space, shall be kept on board and posted at an appropriate place.

3 All accesses from the ro-ro deck and vehicle ramps that lead to spaces below the bulkhead deck shall be closed before the voyage commences and shall remain closed until the ship is at its next berth.

4 The master shall ensure that an effective system of supervision and reporting of the closing and opening of such accesses referred to in paragraph 3 is implemented.

5 The master shall ensure, before the voyage commences, that an entry in the logbook, as required by regulation 22.13, is made of the time of the last closing of the accesses referred to in paragraph 3.

6 Notwithstanding the requirements of paragraph 3, the Administration may permit some accesses to be opened during the voyage, but only for a period sufficient to permit through passage and, if required, for the essential working of the ship.

7 All transverse or longitudinal bulkheads which are taken into account as effective to confine the seawater accumulated on the ro-ro deck shall be in place and secured before the voyage commences and remain in place and secured until the ship is at its next berth.

8 Notwithstanding the requirements of paragraph 7, the Administration may permit some accesses within such bulkheads to be opened during the voyage but only for sufficient time to permit through passage and, if required, for the essential working of the ship.

9 In all ro-ro passenger ships, the master or the designated officer shall ensure that, without the express consent of the master or the designated officer, no passengers are allowed access to an enclosed ro-ro deck during navigation.

Regulation 24

Additional requirements for prevention and control of water ingress, etc., in cargo ships

1 Openings in the shell plating below the deck limiting the vertical extent of damage shall be kept permanently closed during navigation.

2 Notwithstanding the requirements of paragraph 3, the Administration may authorize that particular doors may be opened at the discretion of the master, if necessary for the operation of the ship and provided that the safety of the ship is not impaired.

3 Watertight doors or ramps fitted to internally subdivide large cargo spaces shall be closed before the voyage commences and shall be kept closed during navigation. The time at which such doors are opened or closed shall be recorded in such logbook as may be prescribed by the Administration.

4 The use of access doors and hatch covers intended to ensure the watertight integrity of internal openings shall be authorized by the officer of the watch.

Regulation 25

Water level detectors on single hold cargo ships other than bulk carriers

1 Single hold cargo ships other than bulk carriers constructed before 1 January 2007 shall comply with the requirements of this regulation not later than 31 December 2009.

2 Ships having a length (L) of less than 80 m, or 100 m if constructed before 1 July 1998, and a single cargo hold below the freeboard deck or cargo holds below the freeboard deck which are not separated by at least one bulkhead made watertight up to that deck shall be fitted in such space or spaces with water level detectors.*

3 The water level detectors required by paragraph 2 shall:

.1 give an audible and visual alarm at the navigation bridge when the water level above the inner bottom in the cargo hold reaches a height of not less than 0.3 m, and another when such level reaches not more than 15% of the mean depth of the cargo hold; and

.2 be fitted at the aft end of the hold, or above its lowest part where the inner bottom is not parallel to the designed waterline. Where webs or partial watertight bulkheads are fitted above the inner bottom, Administrations may require the fitting of additional detectors.

4 The water level detectors required by paragraph 2 need not be fitted in ships complying with regulation Xll/12, or in ships having watertight side compartments each side of the cargo hold length extending vertically at least from inner bottom to freeboard deck.

Regulation 25-1

Water level detectors on multiple hold cargo ships other than bulk carriers and tankers

1 Multiple hold cargo ships other than bulk carriers and tankers constructed on or after 1 January 2024 shall be fitted with water level detectors* in each cargo hold intended for dry cargoes. Water level detectors are not required for cargo holds located entirely above the freeboard deck.

SEE INTERPRETATION 1

2 The water level detectors required by paragraph 1 shall:

.1 give audible and visual alarms at the navigation bridge, one when the water level above the bottom of the cargo hold reaches a height of not less than 0.3 m, and another at a height not less than 15% of the depth of the cargo hold but not more than 2 m; and

.2 be fitted at the aft end of the cargo holds. For cargo holds which are occasionally used for water ballast, an alarm overriding device may be installed. The visual alarms shall clearly discriminate between the two different water levels detected in each hold.

3 As an alternative to the water level detector at a height of not less than 0.3 m as per sub-paragraph 2.1, a bilge level sensor* serving the bilge pumping arrangements required by regulation 35-1 and installed in the cargo hold bilge wells or other suitable location is considered acceptable, subject to:

.1 the fitting of the bilge level sensor at a height of not less than 0.3 m at the aft end of the cargo hold;

and

.2 the bilge level sensor giving audible and visual alarm at the navigation bridge which is clearly distinctive from the alarm given by the other water level detector fitted in the cargo hold.

* Refer to Revised performance standards for water /eve/ detectors on ships subject to SOLAS regulations 1/-1/25, 1/-1/25-1 and X/1/12 (resolution MSC.188(79)/Rev.2).

Machinery installations

(Except where expressly provided otherwise part C applies to passenger ships and cargo ships)

Regulation 26

General

1 The machinery, boilers and other pressure vessels, associated piping systems and fittings shall be of a design and construction adequate for the service for which they are intended and shall be so installed and protected as to reduce to a minimum any danger to persons on board, due regard being paid to moving parts, hot surfaces and other hazards. The design shall have regard to materials used in construction, the purpose for which the equipment is intended, the working conditions to which it will be subjected and the environmental conditions on board .*

2 The Administration shall give special consideration to the reliability of single essential propulsion components and may require a separate source of propulsion power sufficient to give the ship a navigable speed, especially in the case of unconventional arrangements.

3 Means shall be provided whereby normal operation of propulsion machinery can be sustained or restored even though one of the essential auxiliaries becomes inoperative. Special consideration shall be given to the malfunctioning of:

.1 a generating set which serves as a main source of electrical power;

.2 the sources of steam supply;

.3 the boiler feedwater systems;

.4 the fuel oil supply systems for boilers or engines;t SEE INTERPRETATION 30

.5 the sources of lubricating oil pressure;

.6 the sources of water pressure;

.7 a condensate pump and the arrangements to maintain vacuum in condensers;

.8 the mechanical air supply for boilers;

.9 an air compressor and receiver for starting or control purposes; and

.10 the hydraulic, pneumatic or electrical means for control in main propulsion machinery including controllable pitch propellers.

However, the Administration, having regard to overall safety considerations, may accept a partial reduction in propulsion capability from normal operation.

• Refer to Guidelines for engine-room layout, design and arrangement (MSC/Circ.834). t Refer to Guidelines to minimize leakages from flammable liquid systems (MSC/Circ.647) and Guidelines on engine-room oil fuel systems (MSC/Circ.851).

Part C Machinery installations

4 Means shall be provided to ensure that the machinery can be brought into operation from the dead ship condition without external aid.

SEE INTERPRETATION 31

5 All boilers, all parts of machinery, all steam, hydraulic, pneumatic and other systems and their associated fittings which are under internal pressure shall be subjected to appropriate tests including a pressure test before being put into service for the first time.

6 Main propulsion machinery and all auxiliary machinery essential to the propulsion and the safety of the ship shall, as fitted in the ship, be designed to operate when the ship is upright and when inclined at any angle of list up to and including 15° either way under static conditions and 22.5° under dynamic conditions (rolling) either way and simultaneously inclined dynamically (pitching) 7.5° by bow or stern. The Administration may permit deviation from these angles, taking into consideration the type, size and service conditions of the ship.

7 Provision shall be made to facilitate cleaning, inspection and maintenance of main propulsion and auxiliary machinery including boilers and pressure vessels.

8 Special consideration shall be given to the design, construction and installation of propulsion machinery systems so that any mode of their vibrations shall not cause undue stresses in this machinery in the normal operating ranges.

9 Non-metallic expansion joints in piping systems, if located in a system which penetrates the ship's side and both the penetration and the non-metallic expansion joint are located below the deepest load waterline, shall be inspected as part of the surveys prescribed in regulation 1/1 0(a) and replaced as necessary, or at an interval recommended by the manufacturer.

10 Operating and maintenance instructions and engineering drawings for ship machinery and equipment essential to the safe operation of the ship shall be written in a language understandable by those officers and crew members who are required to understand such information in the performance of their duties.

11 Location and arrangement of vent pipes for fuel oil service, settling and lubrication oil tanks shall be such that in the event of a broken vent pipe this shall not directly lead to the risk of ingress of seawater splashes or rainwater. Two fuel oil service tanks for each type of fuel used on board necessary for propulsion and vital systems or equivalent arrangements shall be provided on each new ship, with a capacity of at least 8 h at maximum continuous rating of the propulsion plant and normal operating load at sea of the generator plant.* This paragraph applies only to ships constructed on or after 1 July 1998.

SEE INTERPRETATION 32

Regulation 27

Machinery

1 Where risk from overspeeding of machinery exists, means shall be provided to ensure that the safe speed is not exceeded.

2 Where main or auxiliary machinery including pressure vessels or any parts of such machinery are subject to internal pressure and may be subject to dangerous overpressure, means shall be provided where practicable to protect against such excessive pressure.

3 All gearing and every shaft and coupling used for transmission of power to machinery essential for the propulsion and safety of the ship or for the safety of persons on board shall be so designed and constructed that they will withstand the maximum working stresses to which they may be subjected in all service conditions, and due consideration shall be given to the type of engines by which they are driven or of which they form part.

* Refer to regulation 11-2/4.2, Arrangements for oil fuel, lubrication oil and other flammable oils.

4 Internal combustion engines of a cylinder diameter of 200 mm or a crankcase volume of 0.6 m 3 and above shall be provided with crankcase explosion relief valves of a suitable type with sufficient relief area. The relief valves shall be arranged or provided with means to ensure that discharge from them is so directed as to minimize the possibility of injury to personnel.

5 Main turbine propulsion machinery and, where applicable, main internal combustion propulsion machinery and auxiliary machinery shall be provided with automatic shutoff arrangements in the case of failures such as lubricating oil supply failure which could lead rapidly to complete breakdown, serious damage or explosion. The Administration may permit provisions for overriding automatic shutoff devices.

Regulation 28

Means of going astern*

1 Sufficient power for going astern shall be provided to secure proper control of the ship in all normal circumstances.

2 The ability of the machinery to reverse the direction of thrust of the propeller in sufficient time, and so to bring the ship to rest within a reasonable distance from maximum ahead service speed, shall be demonstrated and recorded.

3 The stopping times, ship headings and distances recorded on trials, together with the results of trials to determine the ability of ships having multiple propellers to navigate and manoeuvre with one or more propellers inoperative, shall be available on board for the use of the master or designated personnel.

SEE INTERPRETATION 33

4 Where the ship is provided with supplementary means for manoeuvring or stopping, the effectiveness of such means shall be demonstrated and recorded as referred to in paragraphs 2 and 3.

Regulation 29

Steering geart SEE INTERPRETATION 34

1 Unless expressly provided otherwise, every ship shall be provided with a main steering gear and an auxiliary steering gear to the satisfaction of the Administration. The main steering gear and the auxiliary steering gear shall be so arranged that the failure of one of them will not render the other one inoperative.

SEE INTERPRETATION 35

2.1 All the steering gear components and the rudder stock shall be of sound and reliable construction to the satisfaction of the Administration. Special consideration shall be given to the suitability of any essential component which is not duplicated. Any such essential component shall, where appropriate, utilize antifriction bearings such as ball-bearings, roller-bearings or sleeve-bearings which shall be permanently lubricated or provided with lubrication fittings.

SEE INTERPRETATION 36

2.2 The design pressure for calculations to determine the scantlings of piping and other steering gear components subjected to internal hydraulic pressure shall be at least 1.25 times the maximum working

* Refer to Provision and the display of manoeuvring information on board ships (resolution A.601 (15)), Standards for ship manoeuvrability (resolution MSC.137(76)) and Explanatory notes to the Standards for ship manoeuvrability (MSC/Circ.1053). t Refer to Improved steering gear standards for passenger and cargo ships (resolution A.415(XI)) and Examination of steering gears on existing tankers (resolution A.416(XI)).

pressure to be expected under the operational conditions specified in paragraph 3.2, taking into account any pressure which may exist in the low-pressure side of the system. At the discretion of the Administration, fatigue criteria shall be applied for the design of piping and components, taking into account pulsating pressures due to dynamic loads.

2.3 Relief valves shall be fitted to any part of the hydraulic system which can be isolated and in which pressure can be generated from the power source or from external forces. The setting of the relief valves shall not exceed the design pressure. The valves shall be of adequate size and so arranged as to avoid an undue rise in pressure above the design pressure.

3 The main steering gear and rudder stock shall be:

.1 of adequate strength and capable of steering the ship at maximum ahead service speed which shall be demonstrated;

.2 capable of putting the rudder over from 35° on one side to 35° on the other side with the ship at its deepest seagoing draught and running ahead at maximum ahead service speed and, under the same conditions, from 35° on either side to 30° on the other side in not more than 28 s; where it is impractical to demonstrate compliance with this requirement during sea trials with the ship at its deepest seagoing draught and running ahead at the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch, ships regardless of date of construction may demonstrate compliance with this requirement by one of the following methods:

.1 during sea trials the ship is at even keel and the rudder fully submerged whilst running ahead at the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch; or

.2 where full rudder immersion during sea trials cannot be achieved, an appropriate ahead speed shall be calculated using the submerged rudder blade area in the proposed sea trial loading condition. The calculated ahead speed shall result in a force and torque applied to the main steering gear which is at least as great as if it was being tested with the ship at its deepest seagoing draught and running ahead at the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch; or

.3 the rudder force and torque at the sea trial loading condition have been reliably predicted and extrapolated to the full load condition. The speed of the ship shall correspond to the number of maximum continuous revolutions of the main engine and maximum design pitch of the propeller;

.3 operated by power where necessary to meet the requirements of paragraph 3.2 and in any case when the Administration requires a rudder stock of over 120 mm diameter in way of the tiller, excluding strengthening for navigation in ice; and

.4 so designed that they will not be damaged at maximum astern speed; however, this design requirement need not be proved by trials at maximum astern speed and maximum rudder angle.

SEE INTERPRETATIONS 37 AND 38

4 The auxiliary steering gear shall be:

.1 of adequate strength and capable of steering the ship at navigable speed and of being brought speedily into action in an emergency;

.2 capable of putting the rudder over from 15° on one side to 15° on the other side in not more than

60 s with the ship at its deepest seagoing draught and running ahead at one half of the maximum ahead service speed or 7 knots, whichever is the greater; where it is impractical to demonstrate compliance with this requirement during sea trials with the ship at its deepest seagoing draught and running ahead at one half of the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch or 7 knots, whichever is greater, ships regardless of date of construction, including those constructed before 1 January 2009, may demonstrate compliance with this requirement by one of the following methods:

.1 during sea trials the ship is at even keel and the rudder fully submerged whilst running ahead at one half of the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch or 7 knots, whichever is greater; or

.2 where full rudder immersion during sea trials cannot be achieved, an appropriate ahead speed shall be calculated using the submerged rudder blade area in the proposed sea trial loading condition. The calculated ahead speed shall result in a force and torque applied to the auxiliary steering gear which is at least as great as if it was being tested with the ship at its deepest seagoing draught and running ahead at one half of the speed corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch or 7 knots, whichever is greater; or

.3 the rudder force and torque at the sea trial loading condition have been reliably predicted and extrapolated to the full load condition; and

.3 operated by power where necessary to meet the requirements of paragraph 4.2 and in any case when the Administration requires a rudder stock of over 230 mm diameter in way of the tiller, excluding strengthening for navigation in ice.

SEE INTERPRETATIONS 37 AND 39

5 Main and auxiliary steering gear power units shall be:

.1 arranged to restart automatically when power is restored after a power failure; and

.2 capable of being brought into operation from a position on the navigation bridge. In the event of a power failure to any one of the steering gear power units, an audible and visual alarm shall be given on the navigation bridge.

6.1 Where the main steering gear comprises two or more identical power units, an auxiliary steering gear need not be fitted, provided that:

.1 in a passenger ship, the main steering gear is capable of operating the rudder as required by paragraph 3.2 while any one of the power units is out of operation;

.2 in a cargo ship, the main steering gear is capable of operating the rudder as required by paragraph 3.2 while operating with all power units;

.3 the main steering gear is so arranged that after a single failure in its piping system or in one of the power units the defect can be isolated so that steering capability can be maintained or speedily regained.

SEE INTERPRETATION 40

6.2 The Administration may, until 1 September 1986, accept the fitting of a steering gear which has a proven record of reliability but does not comply with the requirements of paragraph 6.1.3 for a hydraulic system.

6.3 Steering gears, other than of the hydraulic type, shall achieve standards equivalent to the requirements of this paragraph to the satisfaction of the Administration.

7 Steering gear control shall be provided:

.1 for the main steering gear, both on the navigation bridge and in the steering gear compartment;

.2 where the main steering gear is arranged in accordance with paragraph 6, by two independent control systems, both operable from the navigation bridge. This does not require duplication of the steering wheel or steering lever. Where the control system consists of a hydraulic telemotor, a second independent system need not be fitted, except in a tanker, chemical tanker or gas carrier of 10,000 gross tonnage and upwards;

.3 for the auxiliary steering gear, in the steering gear compartment and, if power-operated, it shall also be operable from the navigation bridge and shall be independent of the control system for the main steering gear.

8 Any main and auxiliary steering gear control system operable from the navigation bridge shall comply with the following:

.1 if electric, it shall be served by its own separate circuit supplied from a steering gear power circuit from a point within the steering gear compartment, or directly from switchboard busbars supplying that steering gear power circuit at a point on the switchboard adjacent to the supply to the steering gear power circuit;

.2 means shall be provided in the steering gear compartment for disconnecting any control system operable from the navigation bridge from the steering gear it serves;

.3 the system shall be capable of being brought into operation from a position on the navigation bridge;

.4 in the event of a failure of electrical power supply to the control system, an audible and visual alarm shall be given on the navigation bridge; and

.5 short circuit protection only shall be provided for steering gear control supply circuits.

9 The electrical power circuits and the steering gear control systems with their associated components, cables and pipes required by this regulation and by regulation 30 shall be separated as far as is practicable throughout their length.

10 A means of communication shall be provided between the navigation bridge and the steering gear compartment.

11 The angular position of the rudder shall:

.1 if the main steering gear is power-operated, be indicated on the navigation bridge. The rudder angle indication shall be independent of the steering gear control system;

.2 be recognizable in the steering gear compartment.

12 Hydraulic power-operated steering gear shall be provided with the following:

.1 arrangements to maintain the cleanliness of the hydraulic fluid taking into consideration the type and design of the hydraulic system;

.2 a low-level alarm for each hydraulic fluid reservoir to give the earliest practicable indication of hydraulic fluid leakage. Audible and visual alarms shall be given on the navigation bridge and in the machinery space where they can be readily observed; and

.3 a fixed storage tank having sufficient capacity to recharge at least one power actuating system including the reservoir, where the main steering gear is required to be power-operated. The storage tank shall be permanently connected by piping in such a manner that the hydraulic systems can be readily recharged from a position within the steering gear compartment and shall be provided with a contents gauge.

13 The steering gear compartments shall be:

.1 readily accessible and, as far as practicable, separated from machinery spaces; and

.2 provided with suitable arrangements to ensure working access to steering gear machinery and controls. These arrangements shall include handrails and gratings or other nonslip surfaces to ensure suitable working conditions in the event of hydraulic fluid leakage.

14 Where the rudder stock is required to be over 230 mm diameter in way of the tiller, excluding strengthening for navigation in ice, an alternative power supply, sufficient at least to supply the steering gear power unit which complies with the requirements of paragraph 4.2 and also its associated control system and the rudder angle indicator, shall be provided automatically, within 45 s, either from the emergency source of electrical power or from an independent source of power located in the steering gear compartment. This independent source of power shall be used only for this purpose. In every ship of 10,000 gross tonnage and upwards, the alternative power supply shall have a capacity for at least 30 min of continuous operation and in any other ship for at least 10 min.

SEE INTERPRETATION 41

15 In every tanker, chemical tanker or gas carrier of 10,000 gross tonnage and upwards and in every other ship of 70,000 gross tonnage and upwards, the main steering gear shall comprise two or more identical power units complying with the provisions of paragraph 6.

16 Every tanker, chemical tanker or gas carrier of 10,000 gross tonnage and upwards shall, subject to paragraph 17, comply with the following:

.1 the main steering gear shall be so arranged that in the event of loss of steering capability due to a single failure in any part of one of the power actuating systems of the main steering gear, excluding the tiller, quadrant or components serving the same purpose, or seizure of the rudder actuators, steering capability shall be regained in not more than 45 s after the loss of one power actuating system;

.2 the main steering gear shall comprise either:

.1 two independent and separate power actuating systems, each capable of meeting the requirements of paragraph 3.2; or

.2 at least two identical power actuating systems which, acting simultaneously in normal operation, shall be capable of meeting the requirements of paragraph 3.2. Where necessary to comply with this requirement, interconnection of hydraulic power actuating systems shall be provided. Loss of hydraulic fluid from one system shall be capable of being detected and the defective system automatically isolated so that the other actuating system or systems shall remain fully operational;

.3 steering gears other than of the hydraulic type shall achieve equivalent standards.

17 For tankers, chemical tankers or gas carriers of 10,000 gross tonnage and upwards, but of less than 100,000 tonnes deadweight, solutions other than those set out in paragraph 16, which need not apply the single failure criterion to the rudder actuator or actuators, may be permitted provided that an equivalent safety standard is achieved and that:

.1 following loss of steering capability due to a single failure of any part of the piping system or in one of the power units, steering capability shall be regained within 45 s; and

.2 where the steering gear includes only a single rudder actuator, special consideration is given to stress analysis for the design including fatigue analysis and fracture mechanics analysis, as appropriate, to the material used, to the installation of sealing arrangements and to testing and inspection and to the provision of effective maintenance. In consideration of the foregoing, the Administration shall adopt regulations which include the provisions of the Guidelines for acceptance of non-duplicated rudder actuators for tankers, chemical tankers and gas carriers of 10,000 gross tonnage and above but less than 100,000 tonnes deadweight, adopted by the Organization.*

18 For a tanker, chemical tanker or gas carrier of 10,000 gross tonnage and upwards, but less than 70,000 tonnes deadweight, the Administration may, until 1 September 1986, accept a steering gear system with a proven record of reliability which does not comply with the single failure criterion required for a hydraulic system in paragraph 16.

* Refer to Guidelines for acceptance of non-duplicated rudder actuators for tankers, chemical tankers and gas carriers of 10,000 tons gross tonnage and above but less than 100,000 tons deadweight (resolution A.467(XII) and Corr.1).

19 Every tanker, chemical tanker or gas carrier of 10,000 gross tonnage and upwards, constructed before

1 September 1984, shall comply, not later than 1 September 1986, with the following:

.1 the requirements of paragraphs 7.1, 8.2, 8.4, 10, 11, 12.2, 12.3 and 13.2;

.2 two independent steering gear control systems shall be provided each of which can be operated from the navigation bridge. This does not require duplication of the steering wheel or steering lever;

.3 if the steering gear control system in operation fails, the second system shall be capable of being brought into immediate operation from the navigation bridge; and

.4 each steering gear control system, if electric, shall be served by its own separate circuit supplied from the steering gear power circuit or directly from switchboard busbars supplying that steering gear power circuit at a point on the switchboard adjacent to the supply to the steering gear power circuit.

20 In addition to the requirements of paragraph 19, in every tanker, chemical tanker or gas carrier of 40,000 gross tonnage and upwards, constructed before 1 September 1984, the steering gear shall, not later than 1 September 1988, be so arranged that, in the event of a single failure of the piping or of one of the power units, steering capability can be maintained or the rudder movement can be limited so that steering capability can be speedily regained. This shall be achieved by:

.1 an independent means of restraining the rudder; or

.2 fast-acting valves which may be manually operated to isolate the actuator or actuators from the external hydraulic piping together with a means of directly refilling the actuators by a fixed independent power-operated pump and piping system; or

.3 an arrangement such that, where hydraulic power systems are interconnected, loss of hydraulic fluid from one system shall be detected and the defective system isolated either automatically or from the navigation bridge so that the other system remains fully operational.

Regulation 30

Additional requirements for electric and electrohydraulic steering gear

1 Means for indicating that the motors of electric and electrohydraulic steering gear are running shall be installed on the navigation bridge and at a suitable main machinery control position.

2 Each electric or electrohydraulic steering gear comprising one or more power units shall be served by at least two exclusive circuits fed directly from the main switchboard; however, one of the circuits may be supplied through the emergency switchboard. An auxiliary electric or electrohydraulic steering gear associated with a main electric or electrohydraulic steering gear may be connected to one of the circuits supplying this main steering gear. The circuits supplying an electric or electrohydraulic steering gear shall have adequate rating for supplying all motors which can be simultaneously connected to them and may be required to operate simultaneously.

SEE INTERPRETATION 42

3 Short circuit protection and an overload alarm shall be provided for such circuits and motors. Protection against excess current, including starting current, if provided, shall be for not less than twice the full load current of the motor or circuit so protected, and shall be arranged to permit the passage of the appropriate starting currents. Where a three-phase supply is used an alarm shall be provided that will indicate failure of any one of the supply phases. The alarms required in this paragraph shall be both audible and visual and shall be situated in a conspicuous position in the main machinery space or control room from which the main machinery is normally controlled and as may be required by regulation 51.

4 When in a ship of less than 1,600 gross tonnage an auxiliary steering gear which is required by regulation 29.4.3 to be operated by power is not electrically powered or is powered by an electric motor primarily intended for other services, the main steering gear may be fed by one circuit from the main switchboard. Where such an electric motor primarily intended for other services is arranged to power such an auxiliary steering gear, the requirement of paragraph 3 may be waived by the Administration if satisfied with the protection arrangement together with the requirements of regulation 29.5.1 and .2 and 29.7.3 applicable to auxiliary steering gear.

Regulation 31

Machinery controls

1 Main and auxiliary machinery essential for the propulsion and safety of the ship shall be provided with effective means for its operation and control.

2 Where remote control of propulsion machinery from the navigation bridge is provided and the machinery spaces are intended to be manned, the following shall apply:

.1 the speed, direction of thrust and, if applicable, the pitch of the propeller shall be fully controllable from the navigation bridge under all sailing conditions, including manoeuvring;

.2 the remote control shall be performed, for each independent propeller, by a control device so designed and constructed that its operation does not require particular attention to the operational details of the machinery. Where multiple propellers are designed to operate simultaneously, they may be controlled by one control device;

.3 the main propulsion machinery shall be provided with an emergency stopping device on the navigation bridge which shall be independent of the navigation bridge control system;

.4 propulsion machinery orders from the navigation bridge shall be indicated in the main machinery control room or at the manoeuvring platform as appropriate;

.5 remote control of the propulsion machinery shall be possible only from one location at a time;

at such locations interconnected control positions are permitted. At each location there shall be an indicator showing which location is in control of the propulsion machinery. The transfer of control between the navigation bridge and machinery spaces shall be possible only in the main machinery space or the main machinery control room. This system shall include means to prevent the propelling thrust from altering significantly when transferring control from one location to another;

.6 it shall be possible to control the propulsion machinery locally, even in the case of failure in any part of the remote control system;

.7 the design of the remote control system shall be such that in case of its failure an alarm will be given. Unless the Administration considers it impracticable the preset speed and direction of thrust of the propellers shall be maintained until local control is in operation;

.8 indicators shall be fitted on the navigation bridge for:

.1 propeller speed and direction of rotation in the case of fixed pitch propellers;

.2 propeller speed and pitch position in the case of controllable pitch propellers;

.9 an alarm shall be provided on the navigation bridge and in the machinery space to indicate low starting air pressure which shall be set at a level to permit further main engine starting operations. If the remote control system of the propulsion machinery is designed for automatic starting, the number of automatic consecutive attempts which fail to produce a start shall be limited in order to safeguard sufficient starting air pressure for starting locally.

3 Where the main propulsion and associated machinery, including sources of main electrical supply, are provided with various degrees of automatic or remote control and are under continuous manual supervision from a control room the arrangements and controls shall be so designed, equipped and installed that the machinery operation will be as safe and effective as if it were under direct supervision; for this purpose regulations 46 to 50 shall apply as appropriate. Particular consideration shall be given to protect such spaces against fire and flooding.

4 In general, automatic starting, operational and control systems shall include provisions for manually overriding the automatic controls. Failure of any part of such systems shall not prevent the use of the manual override.

5 Ships constructed on or after 1 July 1998 shall comply with the requirements of paragraphs 1 to 4, as amended, as follows:

.1 paragraph 1 is replaced by the following:

"1 Main and auxiliary machinery essential for the propulsion, control and safety of the ship shall be provided with effective means for its operation and control. All control systems essential for the propulsion, control and safety of the ship shall be independent or designed such that failure of one system does not degrade the performance of another system.";

.2 in the second and third lines of paragraph 2, the words "and the machinery spaces are intended to be manned" are deleted;

.3 the first sentence of paragraph 2.2 is replaced by the following:

".2 the control shall be performed by a single control device for each independent propeller, with automatic performance of all associated services, including, where necessary, means of preventing overload of the propulsion machinery.";

.4 paragraph 2.4 is replaced by the following:

".4 propulsion machinery orders from the navigation bridge shall be indicated in the main machinery control room and at the manoeuvring platform;";

.5 a new sentence is added at the end of paragraph 2.6 to read as follows:

" It shall also be possible to control the auxiliary machinery, essential for the propulsion and safety of the ship, at or near the machinery concerned;"; and

.6 paragraphs 2.8, 2.8.1 and 2.8.2 are replaced by the following:

".8 indicators shall be fitted on the navigation bridge, the main machinery control room and at the manoeuvring platform, for:

.1 propeller speed and direction of rotation in the case of fixed pitch propellers; and

.2 propeller speed and pitch position in the case of controllable pitch propellers;"

6 Ships constructed on or after 1 July 2004 shall comply with the requirements of paragraphs 1 to 5, as amended, as follows:

.1 a new sub-paragraph .10 is added to paragraph 2 to read as follows:

".10 automation systems shall be designed in a manner w hich ensures that threshold warning of impending or imminent slowdown or shutdown of the propulsion system is given to the officer in charge of the navigational watch in time to assess navigational circumstances in an emergency. In particular, the systems shall control, monitor, report, alert and take safety action to slow down or stop propulsion while providing the officer in charge of the navigational watch an opportunity to manually intervene, except for those cases where manual intervention will result in total failure of the engine and/or propulsion equipment within a short time, for example in the case of overspeed."

Regulation 32

Steam boilers and boiler feed systems

1 Every steam boiler and every unfired steam generator shall be provided with not less than two safety valves of adequate capacity. However, having regard to the output or any other features of any boiler or unfired steam generator, the Administration may permit only one safety valve to be fitted if it is satisfied that adequate protection against overpressure is thereby provided.

2 Each oil-fired boiler which is intended to operate without manual supervision shall have safety arrangements which shut off the fuel supply and give an alarm in the case of low water level, air supply failure or flame failure.

3 Water tube boilers serving turbine propulsion machinery shall be fitted with a high water level alarm.

4 Every steam generating system which provides services essential for the safety of the ship, or which could be rendered dangerous by the failure of its feedwater supply, shall be provided with not less than two separate feedwater systems from and including the feed pumps, noting that a single penetration of the steam drum is acceptable. Unless overpressure is prevented by the pump characteristics, means shall be provided which will prevent overpressure in any part of the systems.

5 Boilers shall be provided with means to supervise and control the quality of the feedwater. Suitable arrangements shall be provided to preclude, as far as practicable, the entry of oil or other contaminants which may adversely affect the boiler.

6 Every boiler essential for the safety of the ship and designed to contain water at a specified level shall be provided with at least two means for indicating its water level, at least one of which shall be a direct reading gauge glass.

Regulation 33

Steam pipe systems

1 Every steam pipe and every fitting connected thereto through which steam may pass shall be so designed, constructed and installed as to withstand the maximum working stresses to which it may be subjected.

2 Means shall be provided for draining every steam pipe in which dangerous water hammer action might otherwise occur.

3 If a steam pipe or fitting may receive steam from any source at a higher pressure than that for which it is designed a suitable reducing valve, relief valve and pressure gauge shall be fitted.

Regulation 34

Air pressure systems

1 In every ship means shall be provided to prevent overpressure in any part of compressed air systems and wherever water jackets or casings of air compressors and coolers might be subjected to dangerous overpressure due to leakage into them from air pressure parts. Suitable pressure relief arrangements shall be provided for all systems.

2 The main starting air arrangements for main propulsion internal combustion engines shall be adequately protected against the effects of backfiring and internal explosion in the starting air pipes.

3 All discharge pipes from starting air compressors shall lead directly to the starting air receivers, and all starting pipes from the air receivers to main or auxiliary engines shall be entirely separate from the compressor discharge pipe system.

4 Provision shall be made to reduce to a minimum the entry of oil into the air pressure systems and to drain these systems.

Regulation 35

Ventilating systems in machinery spaces Machinery spaces of category A shall be adequately ventilated so as to ensure that when machinery or boilers therein are operating at full power in all weather conditions including heavy weather, an adequate supply of air is maintained to the spaces for the safety and comfort of personnel and the operation of the machinery. Any other machinery space shall be adequately ventilated appropriate for the purpose of that machinery space.

Regulation 35-1

Bilge pumping arrangements

1 This regulation applies to ships constructed on or after 1 January 2009.

2 Passenger ships and cargo ships

2.1 An efficient bilge pumping system shall be provided, capable of pumping from and draining any watertight compartment other than a space permanently appropriated for the carriage of fresh water, water ballast, oil fuel or liquid cargo and for which other efficient means of pumping are provided, under all practical conditions. Efficient means shall be provided for draining water from insulated holds.

2.2 Sanitary, ballast and general service pumps may be accepted as independent power bilge pumps if fitted with the necessary connections to the bilge pumping system.

2.3 All bilge pipes used in or under coal bunkers or fuel storage tanks or in boiler or machinery spaces, including spaces in which oil-settling tanks or oil fuel pumping units are situated, shall be of steel or other suitable material.

2.4 The arrangement of the bilge and ballast pumping system shall be such as to prevent the possibility of water passing from the sea and from water ballast spaces into the cargo and machinery spaces, or from one compartment to another. Provision shall be made to prevent any deep tank having bilge and ballast connections being inadvertently flooded from the sea when containing cargo, or being discharged through a bilge pump when containing water ballast.

2.5 All distribution boxes and manually operated valves in connection with the bilge pumping arrangements shall be in positions which are accessible under ordinary circumstances.

2.6 Provision shall be made for the drainage of enclosed cargo spaces situated on the bulkhead deck of a passenger ship and on the freeboard deck of a cargo ship, provided that the Administration may permit the means of drainage to be dispensed with in any particular compartment of any ship or class of ship if it is satisfied that by reason of size or internal subdivision of those spaces the safety of the ship is not thereby impaired. For ships subject to the provisions of regulation 11-1 /1.1.1.1, for the special hazards associated with loss of stability when fitted with fixed pressure water-spraying fire-extinguishing systems refer to regulation 11-2/20.6.1 .4.

2.6.1 Where the freeboard to the bulkhead deck or the freeboard deck, respectively, is such that the deck edge is immersed when the ship heels more than 5°, the drainage shall be by means of a sufficient number of scuppers of suitable size discharging directly overboard, fitted in accordance with the requirements of regulation 15 in the case of a passenger ship and the requirements for scuppers, inlets and discharges of the International Convention on Load Lines in force in the case of a cargo ship.

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2.6.2 Where the freeboard is such that the edge of the bulkhead deck or the edge of the freeboard deck, respectively, is immersed when the ship heels 5° or less, the drainage of the enclosed cargo spaces on the bulkhead deck or on the freeboard deck, respectively, shall be led to a suitable space, or spaces, of adequate capacity, having a high water level alarm and provided with suitable arrangements for discharge overboard. In addition it shall be ensured that:

.1 the number, size and disposition of the scuppers are such as to prevent unreasonable accumulation of free water;

.2 the pumping arrangements required by this regulation for passenger ships or cargo ships, as applicable, take account of the requirements for any fixed pressure water-spraying fire-extinguishing system;

.3 water contaminated with petrol or other dangerous substances is not drained to machinery spaces or other spaces where sources of ignition may be present; and

.4 where the enclosed cargo space is protected by a carbon dioxide fire-extinguishing system the deck scuppers are fitted with means to prevent the escape of the smothering gas.

2.6.3 Provisions for the drainage of closed vehicle and ro-ro spaces and special category spaces shall also comply with regulations 11-2/20.6.1.4 and 11-2/20.6.1.5.

3 Passenger ships

3.1 The bilge pumping system required by paragraph 2.1 shall be capable of operation under all practicable conditions after a casualty whether the ship is upright or listed. For this purpose wing suctions shall generally be fitted except in narrow compartments at the end of the ship where one suction may be sufficient. In compartments of unusual form, additional suctions may be required. Arrangements shall be made whereby water in the compartment may find its way to the suction pipes. Where, for particular compartments, the Administration is satisfied that the provision of drainage may be undesirable, it may allow such provision to be dispensed with if calculations made in accordance with the conditions laid down in regulations 7 and 8 show that the survival capability of the ship will not be impaired.

3.2 At least three power pumps shall be fitted connected to the bilge main, one of which may be driven by the propulsion machinery. Where the bilge pump numeral is 30 or more, one additional independent power pump shall be provided. The bilge pump numeral shall be calculated as follows: M + 2P ) when P1 is greater than P: bilge pump numeral = 72 • ( V + P, _ 1p in other cases: bilge pump numeral = 72 • ( M t 2 P)

where: L the length of the ship (metres), as defined in regulation 2; M the volume of the machinery space (cubic metres), as defined in regulation 2, that is below the bulkhead deck; with the addition thereto of the volume of any permanent oil fuel bunkers which may be situated above the inner bottom and forward of, or abaft, the machinery space; P the whole volume of the passenger and crew spaces below the bulkhead deck (cubic metres) which are provided for the accommodation and use of passengers and crew, excluding baggage, store and provision rooms; V the whole volume of the ship below the bulkhead deck (cubic metres); P1 KN, where: N = the number of passengers for which the ship is to be certified; and K = 0.056L However, where the value of KN is greater than the sum of P and the whole volume of the actual passenger spaces above the bulkhead deck, the figure to be taken as P1 is that sum or two-thirds KN, whichever is the greater.

3.3 Where practicable, the power bilge pumps shall be placed in separate watertight compartments and so arranged or situated that these compartments will not be flooded by the same damage. If the main propulsion machinery, auxiliary machinery and boilers are in two or more watertight compartments, the pumps available for bilge service shall be distributed as far as is possible throughout these compartments.

3.4 On a ship of 91.5 m in length L and upwards or having a bilge pump numeral, calculated in accordance with paragraph 3.2, of 30 or more, the arrangements shall be such that at least one power bilge pump shall be available for use in all flooding conditions which the ship is required to withstand, and, for ships subject to the provisions of regulation 11-1/1.1.1.1, in all flooding conditions derived from consideration of minor damages as specified in regulation 8 as follows:

.1 one of the required bilge pumps shall be an emergency pump of a reliable submersible type having a source of power situated above the bulkhead deck; or

.2 the bilge pumps and their sources of power shall be so distributed throughout the length of the ship that at least one pump in an undamaged compartment will be available.

3.5 With the exception of additional pumps which may be provided for peak compartments only, each required bilge pump shall be so arranged as to draw water from any space required to be drained by paragraph 2.1.

3.6 Each power bilge pump shall be capable of pumping water through the required main bilge pipe at a speed of not less than 2 m/s. Independent power bilge pumps situated in machinery spaces shall have direct suctions from these spaces, except that not more than two such suctions shall be required in any one space. Where two or more such suctions are provided, there shall be at least one on each side of the ship. The Administration may require independent power bilge pumps situated in other spaces to have separate direct suctions. Direct suctions shall be suitably arranged and those in a machinery space shall be of a diameter not less than that required for the bilge main.

3.7.1 In addition to the direct bilge suction or suctions required by paragraph 3.6, a direct suction from the main circulating pump leading to the drainage level of the machinery space and fitted with a non-return valve shall be provided in the machinery space. The diameter of this direct suction pipe shall be at least two thirds of the diameter of the pump inlet in the case of steamships, and of the same diameter as the pump inlet in the case of motorships.

3.7.2 Where, in the opinion of the Administration, the main circulating pump is not suitable for this purpose, a direct emergency bilge suction shall be led from the largest available independent power-driven pump to the drainage level of the machinery space; the suction shall be of the same diameter as the main inlet of the pump used. The capacity of the pump so connected shall exceed that of a required bilge pump by an amount deemed satisfactory by the Administration.

3.7.3 The spindles of the sea inlet and direct suction valves shall extend well above the engine-room platform.

3.8 All bilge suction piping up to the connection to the pumps shall be independent of other piping.

3.9 The diameter d of the bilge main shall be calculated according to the following formula. However, the actual internal diameter of the bilge main may be rounded off to the nearest standard size acceptable to the Administration: d = 25 + 1.68✓ L(B + 0) where: dis the internal diameter of the bilge main (millimetres); Land Bare the length and the breadth of the ship (metres) as defined in regulation 2; and

0 is the moulded depth of the ship to the bulkhead deck (metres) provided that, in a ship having an enclosed cargo space on the bulkhead deck which is internally drained in accordance with the requirements of paragraph 2.6.2 and which extends for the full length of the ship, 0 shall be measured to the next deck above the bulkhead deck. Where the enclosed cargo spaces cover a lesser length, 0 shall be taken as the moulded depth to the bulkhead deck plus lh!L where/ and h are the aggregate length and height, respectively, of the enclosed cargo spaces (metres). The diameter of the bilge branch pipes shall meet the requirements of the Administration.

3.10 Provision shall be made to prevent the compartment served by any bilge suction pipe being flooded in the event of the pipe being severed or otherwise damaged by collision or grounding in any other compartment. For this purpose, where the pipe is at any part situated nearer the side of the ship than one fifth of the breadth of the ship (as defined in regulation 2 and measured at right angles to the centreline at the level of the deepest subdivision load line), or is in a duct keel, a non-return valve shall be fitted to the pipe in the compartment containing the open end. For ships subject to the provisions of regulation 11-1/1.1.1.1, the deepest subdivision load line shall be taken as the deepest subdivision draught.

3.11 Distribution boxes, cocks and valves in connection with the bilge pumping system shall be so arranged that, in the event of flooding, one of the bilge pumps may be operative on any compartment; in addition, damage to a pump or its pipe connecting to the bilge main outboard of a line drawn at one fifth of the breadth of the ship shall not put the bilge system out of action. If there is only one system of pipes common to all the pumps, the necessary valves for controlling the bilge suctions must be capable of being operated from above the bulkhead deck. Where, in addition to the main bilge pumping system, an emergency bilge pumping system is provided, it shall be independent of the main system and so arranged that a pump is capable of operating on any compartment under flooding condition as specified in paragraph 3.1; in that case only the valves necessary for the operation of the emergency system need be capable of being operated from above the bulkhead deck.

3.12 All cocks and valves referred to in paragraph 3.11 which can be operated from above the bulkhead deck shall have their controls at their place of operation clearly marked and shall be provided with means to indicate whether they are open or closed.

4 Cargo ships At least two power pumps connected to the main bilge system shall be provided, one of which may be driven by the propulsion machinery. If the Administration is satisfied that the safety of the ship is not impaired, bilge pumping arrangements may be dispensed with in particular compartments.

Regulation 36 *

Regulation 37

Communication between navigation bridge and machinery space

1 At least two independent means shall be provided for communicating orders from the navigation bridge to the position in the machinery space or in the control room from which the engines are normally controlled: one of these shall be an engine-room telegraph which provides visual indication of the orders and responses both in the machinery space and on the navigation bridge. Appropriate means of communication shall be provided to any other positions from which the engines may be controlled.

2 For ships constructed on or after 1 October 1994 the following requirements apply in lieu of the provisions of paragraph 1: At least two independent means shall be provided for communicating orders from the navigation bridge to the position in the machinery space or in the control room from which the speed and direction of thrust of the propellers are normally controlled; one of these shall be an engine-room telegraph which provides visual indication of the orders and responses both in the machinery spaces and on the navigation bridge. Appropriate means of communication shall be provided from the navigation bridge and the engine-room to any other position from which the speed or direction of thrust of the propellers may be controlled.

Regulation 38

Engineers/ alarm An engineers' alarm shall be provided to be operated from the engine control room or at the manoeuvring platform as appropriate, and shall be clearly audible in the engineers' accommodation.

Regulation 39

Location of emergency installations in passenger ships Emergency sources of electrical power, fire pumps, bilge pumps except those specifically serving the spaces forward of the collision bulkhead, any fixed fire-extinguishing system required by chapter 11-2 and other emergency installations which are essential for the safety of the ship, except anchor windlasses, shall not be installed forward of the collision bulkhead.

* This regulation is deliberately left blank.

Electrical installations

(Except where expressly provided otherwise part D applies to passenger ships and cargo ships)

Regulation 40

General SEE INTERPRETATION 44

1 Electrical installations shall be such that:

.1 all electrical auxiliary services necessary for maintaining the ship in normal operational and habitable conditions will be ensured without recourse to the emergency source of electrical power;

.2 electrical services essential for safety will be ensured under various emergency conditions; and

.3 the safety of passengers, crew and ship from electrical hazards will be ensured.

2 The Administration shall take appropriate steps to ensure uniformity in the implementation and application of the provisions of this part in respect of electrical installations.*

Regulation 41

Main source of electrical power and lighting systems SEE INTERPRETATION 44

1.1 A main source of electrical power of sufficient capacity to supply all those services mentioned in regulation 40.1.1 shall be provided. This main source of electrical power shall consist of at least two generating sets.

1.2 The capacity of these generating sets shall be such that in the event of any one generating set being stopped it will still be possible to supply those services necessary to provide normal operational conditions of propulsion and safety. Minimum comfortable conditions of habitability shall also be ensured which include at least adequate services for cooking, heating, domestic refrigeration, mechanical ventilation, sanitary and fresh water.

SEE INTERPRETATION 45

1.3 The arrangements of the ship's main source of electrical power shall be such that the services referred to in regulation 40.1.1 can be maintained regardless of the speed and direction of rotation of the propulsion machinery or shafting.

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1.4 In addition, the generating sets shall be such as to ensure that with any one generator or its primary source of power out of operation, the remaining generating sets shall be capable of providing the electrical services necessary to start the main propulsion plant from a dead ship condition. The emergency source of

* Refer to the recommendations published by the International Electrotechnical Commission and, in particular, publication IEC 60092, Electrical installations in ships.

electrical power may be used for the purpose of starting from a dead ship condition if its capability either alone or combined with that of any other source of electrical power is sufficient to provide at the same time those services required to be supplied by regulations 42.2.1 to 42.2.3 or 43.2.1 to 43.2.4.

1.5 Where transformers constitute an essential part of the electrical supply system required by this paragraph, the system shall be so arranged as to ensure the same continuity of the supply as is stated in this paragraph.

2.1 A main electric lighting system which shall provide illumination throughout those parts of the ship normally accessible to and used by passengers or crew shall be supplied from the main source of electrical power.

2.2 The arrangement of the main electric lighting system shall be such that a fire or other casualty in spaces containing the main source of electrical power, associated transforming equipment, if any, the main switchboard and the main lighting switchboard, will not render the emergency electric lighting system required by regulations 42.2.1 and 42.2.2 or 43.2.1, 43.2.2 and 43.2.3 inoperative.

2.3 The arrangement of the emergency electric lighting system shall be such that a fire or other casualty in spaces containing the emergency source of electrical power, associated transforming equipment, if any, the emergency switchboard and the emergency lighting switchboard will not render the main electric lighting system required by this regulation inoperative.

3 The main switchboard shall be so placed relative to one main generating station that, as far as is practicable, the integrity of the normal electrical supply may be affected only by a fire or other casualty in one space. An environmental enclosure for the main switchboard, such as may be provided by a machinery control room situated within the main boundaries of the space, is not to be considered as separating the switchboards from the generators.

4 Where the total installed electrical power of the main generating sets is in excess of 3 MW, the main busbars shall be subdivided into at least two parts which shall normally be connected by removable links or other approved means; so far as is practicable, the connection of generating sets and any other duplicated equipment shall be equally divided between the parts. Equivalent arrangements may be permitted to the satisfaction of the Administration.

5 Ships constructed on or after 1 July 1998:

.1 in addition to paragraphs 1 to 3, shall comply with the following:

.1 where the main source of electrical power is necessary for propulsion and steering of the ship, the system shall be so arranged that the electrical supply to equipment necessary for propulsion and steering and to ensure safety of the ship will be maintained or immediately restored in the case of loss of any one of the generators in service;

SEE INTERPRETATION 47

.2 load shedding or other equivalent arrangements shall be provided to protect the generators required by this regulation against sustained overload;

SEE INTERPRETATION 48

.3 where the main source of electrical power is necessary for propulsion of the ship, the main busbar shall be subdivided into at least two parts which shall normally be connected by circuit breakers or other approved means; so far as is practicable, the connection of generating sets and other duplicated equipment shall be equally divided between the parts; and SEE INTERPRETATION 49

.2 need not comply with paragraph 4.

6 In passenger ships constructed on or after 1 July 2010, supplementary lighting shall be provided in all cabins to clearly indicate the exit so that occupants will be able to find their way to the door. Such lighting, which may be connected to an emergency source of power or have a self-contained source of electrical

Part D Electrical installations

power in each cabin, shall automatically illuminate when power to the normal cabin lighting is lost and remain on for a minimum of 30 min.

Regulation 42

Emergency source of electrical power in passenger ships SEE INTERPRETATION 50

(Paragraphs 2.6.1 and 4.2 of this regulation apply to ships constructed on or after 1 February 1992)

1.1 A self-contained emergency source of electrical power shall be provided.

1.2 The emergency source of electrical power, associated transforming equipment, if any, transitional source of emergency power, emergency switchboard and emergency lighting switchboard shall be located above the uppermost continuous deck and shall be readily accessible from the open deck. They shall not be located forward of the collision bulkhead.

1.3 The location of the emergency source of electrical power and associated transforming equipment, if any, the transitional source of emergency power, the emergency switchboard and the emergency electric lighting switchboards in relation to the main source of electrical power, associated transforming equipment, if any, and the main switchboard shall be such as to ensure to the satisfaction of the Administration that a fire or other casualty in spaces containing the main source of electrical power, associated transforming equipment, if any, and the main switchboard or in any machinery space of category A will not interfere with the supply, control and distribution of emergency electrical power. As far as practicable, the space containing the emergency source of electrical power, associated transforming equipment, if any, the transitional source of emergency electrical power and the emergency switchboard shall not be contiguous to the boundaries of machinery spaces of category A or those spaces containing the main source of electrical power, associated transforming equipment, if any, or the main switchboard.

1.4 Provided that suitable measures are taken for safeguarding independent emergency operation under all circumstances, the emergency generator may be used exceptionally, and for short periods, to supply non-emergency circuits.

2 The electrical power available shall be sufficient to supply all those services that are essential for safety in an emergency, due regard being paid to such services as may have to be operated simultaneously. The emergency source of electrical power shall be capable, having regard to starting currents and the transitory nature of certain loads, of supplying simultaneously at least the following services for the periods specified hereinafter, if they depend upon an electrical source for their operation:

2.1 For a period of 36 h, emergency lighting:

.1 at every muster and embarkation station and over the sides as required by regulations 111/11.4 and 111/16.7;

.2 in alleyways, stairways and exits giving access to the muster and embarkation stations, as required by regulation 111/11.5;

.3 in all service and accommodation alleyways, stairways and exits, personnel lift cars;

.4 in the machinery spaces and main generating stations including their control positions;

.5 in all control stations, machinery control rooms, and at each main and emergency switchboard;

.6 at all stowage positions for firemen's outfits;

.7 at the steering gear; and

.8 at the fire pump, the sprinkler pump and the emergency bilge pump referred to in paragraph 2.4 and at the starting position of their motors.

2.2 For a period of 36 h:

.1 the navigation lights and other lights required by the International Regulations for Preventing Collisions at Sea in force; and

.2 on ships constructed on or after 1 February 1995, the VHF radio installation required by regulation IV/7.1.1 and IV/7.1.2; and, if applicable:

.1 the MF radio installation required by regulations IV/9.1.1, IV/9.1.2, IV/10.1.2 and IV/10.1.3;

.2 the ship earth station required by regulation IV/10.1.1; and

.3 the MF/HF radio installation required by regulations IV/11.1.1 and IV/11.1.2.

2.3 For a period of 36 h:

.1 all internal communication equipment required in an emergency;

.2 the shipborne navigational equipment as required by regulation V/19; where such provision is unreasonable or impracticable the Administration may waive this requirement for ships of less than 5,000 gross tonnage;

.3 the fire detection and fire alarm system, and the fire door holding and release system; and

.4 for intermittent operation of the daylight signalling lamp, the ship's whistle, the manually operated call points, and all internal signals that are required in an emergency;

unless such services have an independent supply for the period of 36 h from an accumulator battery suitably located for use in an emergency.

2.4 For a period of 36 h:

.1 one of the fire pumps required by regulations 11-2/10.2.2.2 and 11-2/ 10.2.2.3;

.2 the automatic sprinkler pump, if any; and

.3 the emergency bilge pump and all the equipment essential for the operation of electrically powered remote controlled bilge valves.

2.5 For the period of time required by regulation 29.14 the steering gear if required to be so supplied by that regulation.

2.6 For a period of half an hour:

.1 any watertight doors required by regulation 15 to be power-operated together with their indicators and warning signals;

.2 the emergency arrangements to bring the lift cars to deck level for the escape of persons. The passenger lift cars may be brought to deck level sequentially in an emergency.

2.7 In a ship engaged regularly on voyages of short duration, the Administration if satisfied that an adequate standard of safety would be attained may accept a lesser period than the 36 h period specified in paragraphs 2.1 to 2.4 but not less than 12 h.

3 The emergency source of electrical power may be either a generator or an accumulator battery, which shall comply with the following:

3.1 Where the emergency source of electrical power is a generator, it shall be:

.1 driven by a suitable prime mover with an independent supply of fuel having a flashpoint (closed-cup test) of not less than 43°C;

.2 started automatically upon failure of the electrical supply from the main source of electrical power and shall be automatically connected to the emergency switchboard; those services referred to in paragraph 4 shall then be transferred automatically to the emergency generating set. The automatic starting system and the characteristic of the prime mover shall be such as to permit the emergency generator to carry its full rated load as quickly as is safe and practicable, subject to a maximum of 45 s; unless a second independent means of starting the emergency generating set is provided, the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system; and

.3 provided with a transitional source of emergency electrical power according to paragraph 4.

3.2 Where the emergency source of electrical power is an accumulator battery, it shall be capable of:

.1 carrying the emergency electrical load without recharging while maintaining the voltage of the battery throughout the discharge period within 12% above or below its nominal voltage;

.2 automatically connecting to the emergency switchboard in the event of failure of the main source of electrical power; and

.3 immediately supplying at least those services specified in paragraph 4.

3.3 The following provisions in paragraph 3.1.2 shall not apply to ships constructed on or after 1 October 1994:

Unless a second independent means of starting the emergency generating set is provided, the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system.

3.4 For ships constructed on or after 1 July 1998, where electrical power is necessary to restore propulsion, the capacity shall be sufficient to restore propulsion to the ship in conjunction with other machinery, as appropriate, from a dead ship condition within 30 min after blackout.

4 The transitional source of emergency electrical power required by paragraph 3.1.3 shall consist of an accumulator battery suitably located for use in an emergency which shall operate without recharging while maintaining the voltage of the battery throughout the discharge period within 12% above or below its nominal voltage and be of sufficient capacity and so arranged as to supply automatically in the event of failure of either the main or emergency source of electrical power at least the following services, if they depend upon an electrical source for their operation:

4.1 For half an hour:

.1 the lighting required by paragraphs 2.1 and 2.2;

.2 all services required by paragraphs 2.3.1 , 2.3.3 and 2.3.4 unless such services have an independent supply for the period specified from an accumulator battery suitably located for use in an emergency.

4.2 Power to operate the watertight doors, as required by regulation 13.6.3.3, but not necessarily all of them simultaneously, unless an independent temporary source of stored energy is provided. Power to the control, indication and alarm circuits as required by regulation 13.6.2 for half an hour.

5.1 The emergency switchboard shall be installed as near as is practicable to the emergency source of electrical power.

5.2 Where the emergency source of electrical power is a generator, the emergency switchboard shall be located in the same space unless the operation of the emergency switchboard would thereby be impaired.

5.3 No accumulator battery fitted in accordance with this regulation shall be installed in the same space as the emergency switchboard. An indicator shall be mounted in a suitable place on the main switchboard or in the machinery control room to indicate when the batteries constituting either the emergency source of electrical power or the transitional source of emergency electrical power referred to in paragraph 3.1.3 or 4 are being discharged.

5.4 The emergency switchboard shall be supplied during normal operation from the main switchboard by an interconnector feeder which is to be adequately protected at the main switchboard against overload and short circuit and which is to be disconnected automatically at the emergency switchboard upon failure of the main source of electrical power. Where the system is arranged for feedback operation, the interconnector feeder is also to be protected at the emergency switchboard at least against short circuit.

5.5 In order to ensure ready availability of the emergency source of electrical power, arrangements shall be made where necessary to disconnect automatically non-emergency circuits from the emergency switchboard to ensure that power shall be available to the emergency circuits.

6 The emergency generator and its prime mover and any emergency accumulator battery shall be so designed and arranged as to ensure that they will function at full rated power when the ship is upright and when inclined at any angle of list up to 22.5° or when inclined up to 10° either in the fore or aft direction, or is in any combination of angles within those limits.

7 Provision shall be made for the periodic testing of the complete emergency system and shall include the testing of automatic starting arrangements.

Regulation 42-1

Supplementary emergency lighting for ro-ro passenger ships (This regulation applies to all passenger ships with ro-ro cargo spaces or special category spaces as defined in regulation 1/-2/3, except that for ships constructed before 22 October 1989, this regulation shall apply not later than 22 October 1990)

1 In addition to the emergency lighting required by regulation 42.2, on every passenger ship with ro-ro cargo spaces or special category spaces as defined in regulation 11-2/3:

.1 all passenger public spaces and alleyways shall be provided with supplementary electric lighting that can operate for at least 3 h when all other sources of electrical power have failed and under any condition of heel. The illumination provided shall be such that the approach to the means of escape can be readily seen. The source of power for the supplementary lighting shall consist of accumulator batteries located within the lighting units that are continuously charged, where practicable, from the emergency switchboard. Alternatively, any other means of lighting which is at least as effective may be accepted by the Administration. The supplementary lighting shall be such that any failure of the lamp will be immediately apparent. Any accumulator battery provided shall be replaced at intervals having regard to the specified service life in the ambient conditions that they are subject to in service; and

.2 a portable rechargeable battery operated lamp shall be provided in every crew space alleyway, recreational space and every working space which is normally occupied unless supplementary emergency lighting, as required by sub-paragraph .1, is provided.

Regulation 43

Emergency source of electrical power in cargo ships SEE INTERPRETATION 50

1.1 A self-contained emergency source of electrical power shall be provided.

1.2 The emergency source of electrical power, associated transforming equipment, if any, transitional source of emergency power, emergency switchboard and emergency lighting switchboard shall be located above the uppermost continuous deck and shall be readily accessible from the open deck. They shall not be located forward of the collision bulkhead, except where permitted by the Administration in exceptional circumstances.

1.3 The location of the emergency source of electrical power, associated transforming equipment, if any, the transitional source of emergency power, the emergency switchboard and the emergency lighting switchboard in relation to the main source of electrical power, associated transforming equipment, if any, and the main switchboard shall be such as to ensure to the satisfaction of the Administration that a fire or other casualty in the space containing the main source of electrical power, associated transforming equipment, if any, and the main switchboard, or in any machinery space of category A will not interfere with the supply, control and distribution of emergency electrical power. As far as practicable the space containing the emergency source of electrical power, associated transforming equipment, if any, the transitional source of emergency electrical power and the emergency switchboard shall not be contiguous to the boundaries of machinery spaces of category A or those spaces containing the main source of electrical power, associated transforming equipment, if any, and the main switchboard.

1.4 Provided that suitable measures are taken for safeguarding independent emergency operation under all circumstances, the emergency generator may be used, exceptionally, and for short periods, to supply non-emergency circuits.

2 The electrical power available shall be sufficient to supply all those services that are essential for safety in an emergency, due regard being paid to such services as may have to be operated simultaneously. The emergency source of electrical power shall be capable, having regard to starting currents and the transitory nature of certain loads, of supplying simultaneously at least the following services for the periods specified hereinafter, if they depend upon an electrical source for their operation:

2.1 For a period of 3 h, emergency lighting at every muster and embarkation station and over the sides as required by regulations 111/11.4 and 111/16.7.

2.2 For a period of 18 h, emergency lighting:

.1 in all service and accommodation alleyways, stairways and exits, personnel lift cars and personnel lift trunks;

.2 in the machinery spaces and main generating stations including their control positions;

.3 in all control stations, machinery control rooms, and at each main and emergency switchboard;

.4 at all stowage positions for firemen's outfits;

.5 at the steering gear;

.6 at the fire pump referred to in paragraph 2.5, at the sprinkler pump, if any, and at the emergency bilge pump, if any, and at the starting positions of their motors; and

.7 in all cargo pump-rooms of tankers constructed on or after 1 July 2002.

2.3 For a period of 18 h:

.1 the navigation lights and other lights required by the International Regulations for Preventing Collisions at Sea in force;

.2 on ships constructed on or after 1 February 1995 the VHF radio installation required by regulation IV/7.1.1 and IV/7.1.2; and, if applicable:

.1 the MF radio installation required by regulations IV/9.1.1, IV/9.1.2, IV/10.1.2 and IV/10.1.3;

.2 the ship earth station required by regulation IV/ 10.1.1; and

.3 the MF/HF radio installation required by regulations IV/1 1.1 .1 and IV/11.1.2.

2.4 For a period of 18 h:

.1 all internal communication equipment as required in an emergency;

.2 the shipborne navigational equipment as required by regulation V/19; where such provision is unreasonable or impracticable the Administration may waive this requirement for ships of less than 5,000 gross tonnage;

.3 the fire detection and fire alarm system; and

.4 intermittent operation of the daylight signalling lamp, the ship's whistle, the manually operated call points and all internal signals that are required in an emergency;

unless such services have an independent supply for the period of 18 h from an accumulator battery suitably located for use in an emergency.

2.5 For a period of 18 h one of the fire pumps required by regulations 11-2/10.2.2.2 and 11-2/10.2.2.3; if dependent upon the emergency generator for its source of power.

2.6.1 For the period of time required by regulation 29.14 the steering gear where it is required to be so supplied by that regulation.

2.6.2 In a ship engaged regularly in voyages of short duration, the Administration if satisfied that an adequate standard of safety wou Id be attained may accept a lesser period than the 18 h period specified in paragraphs 2 .2 to 2.5 but not less than 12 h.

3 The emergency source of electrical power may be either a generator or an accumulator battery, which shall comply with the following:

3.1 Where the emergency source of electrical power is a generator, it shall be:

.1 driven by a suitable prime mover with an independent supply of fuel, having a flashpoint (closed-cup test) of not less than 43°C;

.2 started automatically upon failure of the main source of electrical power supply unless a transitional source of emergency electrical power in accordance with paragraph 3.1.3 is provided; where the emergency generator is automatically started, it shall be automatically connected to the emergency switchboard; those services referred to in paragraph 4 shall then be connected automatically to the emergency generator; and unless a second independent means of starting the emergency generator is provided the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system; and

.3 provided with a transitional source of emergency electrical power as specified in paragraph 4 unless an emergency generator is provided capable both of supplying the services mentioned in that paragraph and of being automatically started and supplying the required load as quickly as is safe and practicable subject to a maximum of 45 s.

3.2 Where the emergency source of electrical power is an accumulator battery it shall be capable of:

.1 carrying the emergency electrical load without recharging whi le maintaining the voltage of the battery throughout the discharge period w ithin 12% above or below its nominal voltage;

.2 automatically connecting to the emergency switchboard in the event of failure of the main source of electrical power; and

.3 immediately supplying at least those services specified in paragraph 4.

3.3 The following provision in paragraph 3.1.2 shall not apply to ships constructed on or after 1 October 1994:

Unless a second independent means of starting the emergency generating set is provided, the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system.

3.4 For ships constructed on or after 1 July 1998, w here electrical power is necessary to restore propulsion, the capacity shall be sufficient to restore propulsion to the ship in conjunction with other machinery, as appropriate, from a dead ship condition within 30 min after blackout.

4 The transitional source of emergency electrical power where required by paragraph 3.1.3 shall consist of an accumulator battery suitably located for use in an emergency which shall operate without recharging while maintaining the voltage of the battery throughout the discharge period within 12% above or below its nominal voltage and be of sufficient capacity and shall be so arranged as to supply automatically in the event of failure of either the main or the emergency source of electrical power for half an hour at least the following services if they depend upon an electrical source for their operation:

.1 the lighting required by paragraphs 2.1, 2.2 and 2.3.1. For this transitional phase, the required emergency electric lighting, in respect of the machinery space and accommodation and service spaces may be provided by permanently fixed, individual, automatically charged, relay operated accumulator lamps; and

.2 all services required by paragraphs 2.4.1, 2.4.3 and 2.4.4 unless such services have an independent supply for the period specified from an accumulator battery suitably located for use in an emergency.

5.1 The emergency switchboard shall be installed as near as is practicable to the emergency source of electrical power.

5.2 Where the emergency source of electrical power is a generator, the emergency switchboard shall be located in the same space unless the operation of the emergency switchboard would thereby be impaired.

5.3 No accumulator battery fitted in accordance with this regulation shall be installed in the same space as the emergency switchboard. An indicator shall be mounted in a suitable place on the main switchboard or in the machinery control room to indicate when the batteries constituting either the emergency source of electrical power or the transitional source of electrical power referred to in paragraph 3.2 or 4 are being discharged.

5.4 The emergency switchboard shall be supplied during normal operation from the main switchboard by an interconnector feeder which is to be adequately protected at the main switchboard against overload and short circuit and which is to be disconnected automatically at the emergency switchboard upon failure of the main source of electrical power. Where the system is arranged for feedback operation, the interconnector feeder is also to be protected at the emergency switchboard at least against short circuit.

5.5 In order to ensure ready availability of the emergency source of electrical power, arrangements shall be made where necessary to disconnect automatically non-emergency circuits from the emergency switchboard to ensure that electrical power shall be available automatically to the emergency circuits.

6 The emergency generator and its prime mover and any emergency accumulator battery shall be so designed and arranged as to ensure that they will function at full rated power when the ship is upright and when inclined at any angle of list up to 22.5° or when inclined up to 10° either in the fore or aft direction, or is in any combination of angles within those limits.

7 Provision shall be made for the periodic testing of the complete emergency system and shall include the testing of automatic starting arrangements.

Regulation 44

Starting arrangements for emergency generating sets

1 Emergency generating sets shall be capable of being readily started in their cold condition at a temperature of 0°C. If this is impracticable, or if lower temperatures are likely to be encountered, provision acceptable to the Administration shall be made for the maintenance of heating arrangements, to ensure ready starting of the generating sets.

SEE INTERPRETATION 51

2 Each emergency generating set arranged to be automatically started shall be equipped with starting devices approved by the Administration with a stored energy capability of at least three consecutive starts. A second source of energy shall be provided for an additional three starts within 30 min unless manual starting can be demonstrated to be effective.

SEE INTERPRETATION 52

2.1 Ships constructed on or after 1 October 1994, in lieu of the provision of the second sentence of paragraph 2, shall comply with the following requirements: The source of stored energy shall be protected to preclude critical depletion by the automatic starting system, unless a second independent means of starting is provided. In addition, a second source of energy shall be provided for an additional three starts within 30 min unless manual starting can be demonstrated to be effective.

3 The stored energy shall be maintained at all times, as follows:

.1 electrical and hydraulic starting systems shall be maintained from the emergency switchboard;

.2 compressed air starting systems may be maintained by the main or auxiliary compressed air receivers through a suitable non-return valve or by an emergency air compressor which, if electrically driven, is supplied from the emergency switchboard;

.3 all of these starting, charging and energy storing devices shall be located in the emergency generator space; these devices are not to be used for any purpose other than the operation of the emergency generating set. This does not preclude the supply to the air receiver of the emergency generating set from the main or auxiliary compressed air system through the non-return valve fitted in the emergency generator space.

4.1 Where automatic starting is not required, manual starting is permissible, such as manual cranking, inertia starters, manually charged hydraulic accumulators, or powder charge cartridges, where they can be demonstrated as being effective.

4.2 When manual starting is not practicable, the requirements of paragraphs 2 and 3 shall be complied with except that starting may be manually initiated.

Regulation 45

Precautions against shock, fire and other hazards of electrical origin (Paragraphs 10 and 11 of this regulation apply to ships constructed on or after 1 January 2007)

1.1 Exposed metal parts of electrical machines or equipment which are not intended to be live but which are liable under fault conditions to become live shall be earthed unless the machines or equipment are:

.1 supplied at a voltage not exceeding 50 V direct current or 50 V root mean square between conductors; auto-transformers shall not be used for the purpose of achieving this voltage; or

.2 supplied at a voltage not exceeding 250 V by safety isolating transformers supplying only one consuming device; or

.3 constructed in accordance with the principle of double insulation.

1.2 The Administration may require additional precautions for portable electrical equipment for use in confined or exceptionally damp spaces where particular risks due to conductivity may exist.

1.3 All electrical apparatus shall be so constructed and so installed as not to cause injury when handled or touched in the normal manner.

2 Main and emergency switchboards shall be so arranged as to give easy access as may be needed to apparatus and equipment, without danger to personnel. The sides and the rear and, where necessary, the front of switchboards shall be suitably guarded. Exposed live parts having voltages to earth exceeding a voltage to be specified by the Administration shall not be installed on the front of such switchboards. Where necessary, non-conducting mats or gratings shall be provided at the front and rear of the switchboard.

3.1 The hull return system of distribution shall not be used for any purpose in a tanker, or for power, heating, or lighting in any other ship of 1,600 gross tonnage and upwards.

3.2 The requirement of paragraph 3.1 does not preclude under conditions approved by the Administration the use of:

.1 impressed current cathodic protective systems;

.2 limited and locally earthed systems; or

.3 insulation level monitoring devices provided the circulation current does not exceed 30 mA under the most unfavourable conditions.

3.2.1 For ships constructed on or after 1 October 1994, the requirement of paragraph 3.1 does not preclude the use of limited and locally earthed systems, provided that any possible resulting current does not flow directly through any dangerous spaces.

3.3 Where the hull return system is used, all final subcircuits, i.e. all circuits fitted after the last protective device, shall be two-wire and special precautions shall be taken to the satisfaction of the Administration.

4.1 Earthed distribution systems shall not be used in a tanker. The Administration may exceptionally permit in a tanker the earthing of the neutral for alternating current power networks of 3,000 V (line to line) and over, provided that any possible resulting current does not flow directly through any of the dangerous spaces.

4.2 When a distribution system, whether primary or secondary, for power, heating or lighting, with no connection to earth is used, a device capable of continuously monitoring the insulation level to earth and of giving an audible or visual indication of abnormally low insulation values shall be provided.

4.3 Ships constructed on or after 1 October 1994, in lieu of the provisions of paragraph 4.1, shall comply with the following requirements:

.1 Except as permitted by paragraph 4.3.2, earthed distribution systems shall not be used in a tanker.

.2 The requirement of paragraph 4.3.1 does not preclude the use of earthed intrinsically safe circuits and in addition, under conditions approved by the Administration, the use of the following earthed systems:

.1 power-supplied control circuits and instrumentation circuits where technical or safety reasons preclude the use of a system with no connection to earth, provided the current in the hull is limited to not more than 5 A in both normal and fault conditions; or

.2 limited and locally earthed systems, provided that any possible resulting current does not flow directly through any of the dangerous spaces; or

.3 alternating current power networks of 1,000 V root mean square (line to line) and over, provided that any possible resulting current does not flow directly through any of the dangerous spaces.

5.1 Except as permitted by the Administration in exceptional circumstances, all metal sheaths and armour of cables shall be electrically continuous and shall be earthed.

5.2 All electric cables and wiring external to equipment shall be at least of a flame-retardant type and shall be so installed as not to impair their original flame-retarding properties. Where necessary for particular applications the Administration may permit the use of special types of cables such as radio frequency cables, which do not comply with the foregoing.

5.3 Cables and wiring serving essential or emergency power, lighting, internal communications or signals shall so far as practicable be routed clear of galleys, laundries, machinery spaces of category A and their casings and other high fire risk areas. In ro-ro passenger ships, cabling for emergency alarms and public address systems installed on or after 1 July 1998 shall be approved by the Administration having regard to the recommendations developed by the Organization.* Cables connecting fire pumps to the emergency switchboard shall be of a fire-resistant type where they pass through high fire risk areas. Where practicable all such cables should be run in such a manner as to preclude their being rendered unserviceable by heating of the bulkheads that may be caused by a fire in an adjacent space.

5.4 Where cables which are installed in hazardous areas introduce the risk of fire or explosion in the event of an electrical fault in such areas, special precautions against such risks shall be taken to the satisfaction of the Administration.

5.5 Cables and wiring shall be installed and supported in such a manner as to avoid chafing or other damage.

5.6 Terminations and joints in all conductors shall be so made as to retain the original electrical, mechanical, flame-retarding and, where necessary, fire-resisting properties of the cable.

6.1 Each separate circuit shall be protected against short circuit and against overload, except as permitted in regulations 29 and 30 or where the Administration may exceptionally otherwise permit.

6.2 The rating or appropriate setting of the overload protective device for each circuit shall be permanently indicated at the location of the protective device.

• Refer to Recommendation on performance standards for public address systems on passenger ships, including cabling (MSC/Circ.808).

7 Lighting fittings shall be so arranged as to prevent temperature rises which could damage the cables and wiring, and to prevent surrounding material from becoming excessively hot.

8 All lighting and power circuits terminating in a bunker or cargo space shall be provided with a multiple- pole switch outside the space for disconnecting such circuits.

9.1 Accumulator batteries shall be suitably housed, and compartments used primarily for their accommodation shall be properly constructed and efficiently ventilated.

9.2 Electrical or other equipment which may constitute a source of ignition of flammable vapours shall not be permitted in these compartments except as permitted in paragraph 10.

9.3 Accumulator batteries shall not be located in sleeping quarters except where hermetically sealed to the satisfaction of the Administration.

10 No electrical equipment shall be installed in any space where flammable mixtures are liable to collect, e.g. in compartments assigned principally to accumulator batteries, in paint lockers, acetylene stores or similar spaces, unless the Administration is satisfied that such equipment is:

.1 essential for operational purposes;

.2 of a type which will not ignite the mixture concerned;

.3 appropriate to the space concerned; and

.4 appropriately certified for safe usage in the dusts, vapours or gases likely to be encountered.

11 In tankers, electrical equipment, cables and wiring shall not be installed in hazardous locations unless it conforms with standards not inferior to those acceptable to the Organization.* However, for locations not covered by such standards, electrical equipment, cables and wiring which do not conform to the standards may be installed in hazardous locations based on a risk assessment to the satisfaction of the Administration, to ensure that an equivalent level of safety is assured.

SEE INTERPRETATION 53

12 In a passenger ship, distribution systems shall be so arranged that fire in any main vertical zone as is defined in regulation 11-2/3.32 will not interfere with services essential for safety in any other such zone. This requirement will be met if main and emergency feeders passing through any such zone are separated both vertically and horizontally as widely as is practicable.

* Refer to the standards published by the International Electrotechnical Commission, and in particular IEC 60092-502:1999, Electrical installations in ships - Tankers.

Additional requirements for periodically unattended machinery spaces

(Part E applies to cargo ships except that regulation 54 refers to passenger ships)

Regulation 46

General

1 The arrangements provided shall be such as to ensure that the safety of the ship in all sailing conditions, including manoeuvring, is equivalent to that of a ship having the machinery spaces manned.

2 Measures shall be taken to the satisfaction of the Administration to ensure that the equipment is functioning in a reliable manner and that satisfactory arrangements are made for regular inspections and routine tests to ensure continuous reliable operation.

3 Every ship shall be provided with documentary evidence, to the satisfaction of the Administration, of its fitness to operate with periodically unattended machinery spaces.

Regulation 47

Fire precautions

1 Means shall be provided to detect and give alarms at an early stage in case of fires:

.1 in boiler air supply casings and exhausts (uptakes); and

.2 in scavenging air belts of propulsion machinery, unless the Administration considers this to be unnecessary in a particular case.

2 Internal combustion engines of 2,250 kW and above or having cylinders of more than 300 mm bore shall be provided with crankcase oil mist detectors or engine bearing temperature monitors or equivalent devices.

Regulation 48

Protection against flooding

1 Bilge wells in periodically unattended machinery spaces shall be located and monitored in such a way that the accumulation of liquids is detected at normal angles of trim and heel, and shall be large enough to accommodate easily the normal drainage during the unattended period.

2 Where the bilge pumps are capable of being started automatically, means shall be provided to indicate when the influx of liquid is greater than the pump capacity or when the pump is operating more frequently than would normally be expected. In these cases, smaller bilge wells to cover a reasonable period of time may be permitted. Where automatically controlled bilge pumps are provided, special attention shall be given to oil pollution prevention requirements.

3 The location of the controls of any valve serving a sea inlet, a discharge below the waterline or a bilge injection system shall be so sited as to allow adequate time for operation in case of influx of water to the space, having regard to the time likely to be required in order to reach and operate such controls. If the level to which the space could become flooded with the ship in the fully loaded condition so requires, arrangements shall be made to operate the controls from a position above such level.

SEE INTERPRETATION 54

Regulation 49

Control of propulsion machinery from the navigation bridge

1 Under all sailing conditions, including manoeuvring, the speed, direction of thrust and, if applicable, the pitch of the propeller shall be fully controllable from the navigation bridge.

1.1 Such remote control shall be performed by a single control device for each independent propeller, with automatic performance of all associated services, including, where necessary, means of preventing overload of the propulsion machinery.

1.2 The main propulsion machinery shall be provided with an emergency stopping device on the navigation bridge which shall be independent of the navigation bridge control system.

2 Propulsion machinery orders from the navigation bridge shall be indicated in the main machinery control room or at the propulsion machinery control position as appropriate.

3 Remote control of the propulsion machinery shall be possible only from one location at a time; at such locations interconnected control positions are permitted. At each location there shall be an indicator showing which location is in control of the propulsion machinery. The transfer of control between the navigation bridge and machinery spaces shall be possible only in the main machinery space or in the main machinery control room. The system shall include means to prevent the propelling thrust from altering significantly when transferring control from one location to another.

4 It shall be possible for all machinery essential for the safe operation of the ship to be controlled from a local position, even in the case of failure in any part of the automatic or remote control systems.

5 The design of the remote automatic control system shall be such that in case of its failure an alarm will be given. Unless the Administration considers it impracticable, the preset speed and direction of thrust of the propeller shall be maintained until local control is in operation.

6 Indicators shall be fitted on the navigation bridge for:

.1 propeller speed and direction of rotation in the case of fixed pitch propellers; or

.2 propeller speed and pitch position in the case of controllable pitch propellers.

7 The number of consecutive automatic attempts which fail to produce a start shall be limited to safeguard sufficient starting air pressure. An alarm shall be provided to indicate low starting air pressure set at a level which still permits starting operations of the propulsion machinery.

Regulation 50

Communication A reliable means of vocal communication shall be provided between the main machinery control room or the propulsion machinery control position as appropriate, the navigation bridge and the engineer officers' accommodation.

Part E Additional requirements for periodically unattended machinery spaces

Regulation 51

Alarm system

1 An alarm system shall be provided indicating any fault requiring attention and shall:

.1 be capable of sounding an audible alarm in the main machinery control room or at the propulsion machinery control position, and indicate visually each separate alarm function at a suitable position;

.2 have a connection to the engineers' public rooms and to each of the engineers' cabins through a selector switch, to ensure connection to at least one of those cabins. Administrations may permit equivalent arrangements;

.3 activate an audible and visual alarm on the navigation bridge for any situation which requires action by or attention of the officer on watch;

.4 as far as is practicable be designed on the fail-to-safety principle; and

.5 activate the engineers' alarm required by regulation 38 if an alarm function has not received attention locally within a limited time.

2.1 The alarm system shall be continuously powered and shall have an automatic change-over to a stand-by power supply in case of loss of normal power supply.

2.2 Failure of the normal power supply of the alarm system shall be indicated by an alarm.

3.1 The alarm system shall be able to indicate at the same time more than one fault and the acceptance of any alarm shall not inhibit another alarm.

3.2 Acceptance at the position referred to in paragraph 1 of any alarm condition shall be indicated at the positions where it was shown. Alarms shall be maintained until they are accepted and the visual indications of individual alarms shall remain until the fault has been corrected, when the alarm system shall automatically reset to the normal operating condition.

Regulation 52

Safety systems A safety system shall be provided to ensure that serious malfunction in machinery or boiler operations, which presents an immediate danger, shall initiate the automatic shutdown of that part of the plant and that an alarm shall be given. Shutdown of the propulsion system shall not be automatically activated except in cases which could lead to serious damage, complete breakdown, or explosion. Where arrangements for overriding the shutdown of the main propelling machinery are fitted, these shall be such as to preclude inadvertent operation. Visual means shall be provided to indicate when the override has been activated.

Regulation 53

Special requirements for machiner)/J boiler and electrical installations

1 The special requirements for the machinery, boiler and electrical installations shall be to the satisfaction of the Administration and shall include at least the requirements of this regulation.

2 The main source of electrical power shall comply with the following:

2.1 Where the electrical power can normally be supplied by one generator, suitable load-shedding arrangements shall be provided to ensure the integrity of supplies to services required for propulsion and steering as well as the safety of the ship. In the case of loss of the generator in operation, adequate provision shall be made for automatic starting and connecting to the main switchboard of a stand-by generator of sufficient capacity to permit propulsion and steering and to ensure the safety of the ship with automatic restarting of the essential auxiliaries including, where necessary, sequential operations. The Administration may dispense with this requirement for a ship of less than 1,600 gross tonnage, if it is considered impracticable.

2.2 If the electrical power is normally supplied by more than one generator simultaneously in parallel operation, provision shall be made, for instance by load shedding, to ensure that, in case of loss of one of these generating sets, the remaining ones are kept in operation without overload to permit propulsion and steering, and to ensure the safety of the ship.

3 Where stand-by machines are required for other auxiliary machinery essential to propulsion, automatic change-over devices shall be provided.

4 Automatic control and alarm system

4.1 The control system shall be such that the services needed for the operation of the main propulsion machinery and its auxiliaries are ensured through the necessary automatic arrangements.

4.2 An alarm shall be given on the automatic change-over.

4.3 An alarm system complying with regulation 51 shall be provided for all important pressures, temperatures and fluid levels and other essential parameters.

4.4 A centralized control position shall be arranged with the necessary alarm panels and instrumentation indicating any alarm.

5 Means shall be provided to keep the starting air pressure at the required level where internal combustion engines are used for main propulsion.

Regulation 54

Special consideration in respect of passenger ships Passenger ships shall be specially considered by the Administration as to whether or not their machinery spaces may be periodically unattended and if so whether additional requirements to those stipulated in these regulations are necessary to achieve equivalent safety to that of normally attended machinery spaces.

Alternative design and arrangements

Regulation 55

Alternative design and arrangements

1 Purpose The purpose of this regulation is to provide a methodology for alternative design and arrangements for machinery, electrical installations and low-flashpoint fuel storage and distribution systems.

2 General

2.1 Machinery, electrical installation and low-flashpoint fuel storage and distribution systems design and arrangements may deviate from the requirements set out in parts C, D, E or G, provided that the alternative design and arrangements meet the intent of the requirements concerned and provide an equivalent level of safety to this chapter.

2.2 When alternative design or arrangements deviate from the prescriptive requirements of parts C, D, E or G, an engineering analysis, evaluation and approval of the design and arrangements shall be carried out in accordance with this regulation.

3 Engineering analysis The engineering analysis shall be prepared and submitted to the Administration, based on the guidelines developed by the Organization* and shall include, as a minimum, the following elements:

.1 determination of the ship type, machinery, electrical installations, low-flashpoint fuel storage and distribution systems and space(s) concerned;

.2 identification of the prescriptive requirement(s) with which the machinery, electrical installations and low-flashpoint fuel storage and distribution systems will not comply;

.3 identification of the reason the proposed design will not meet the prescriptive requirements supported by compliance with other recognized engineering or industry standards;

.4 determination of the performance criteria for the ship, machinery, electrical installation, low-flashpoint fuel storage and distribution system or the space(s) concerned addressed by the relevant prescriptive requirement(s):

.1 performance criteria shall provide a level of safety not inferior to the relevant prescriptive requirements contained in parts C, D, E or G; and

.2 performance criteria shall be quantifiable and measurable;

.5 detailed description of the alternative design and arrangements, including a list of the assumptions used in the design and any proposed operational restrictions or conditions;

.6 technical justification demonstrating that the alternative design and arrangements meet the safety performance criteria; and

* Refer to Revised guidelines on alternative design and arrangements for SOLAS chapters 1/-1 and Ill (MSC.1/Circ.1212/Rev.2) and the Guidelines for the approval of alternatives and equivalents as provided for in various /MO instruments (MSC.1/Circ.1455).

.7 risk assessment based on identification of the potential faults and hazards associated with the proposal.

4 Evaluation of the alternative design and arrangements

4.1 The engineering analysis required in paragraph 3 shall be evaluated and approved by the Administration, taking into account the guidelines developed by the Organization.*

4.2 A copy of the documentation, as approved by the Administration, indicating that the alternative design and arrangements comply with this regulation shall be carried on board the ship.

5 Exchange of information The Administration shall communicate to the Organization pertinent information concerning alternative design and arrangements approved by them for circulation to all Contracting Governments.

6 Re-evaluation due to change of conditions If the assumptions and operational restrictions that were stipulated in the alternative design and arrangements are changed, the engineering analysis shall be carried out under the changed condition and shall be approved by the Administration.

* Refer to Revised guidelines on alternative design and arrangements for SOLAS chapters 1/-1 and Ill (MSC.1/Circ.1212/Rev.2).

Ships using low-flashpoint fuels

Regulation 56

Application

1 Except as provided for in paragraphs 4 and 5, this part shall apply to ships using low-flashpoint fuels:

.1 for which the building contract is placed on or after 1 January 2017;

.2 in the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1 July 2017; or

.3 the delivery of which is on or after 1 January 2021.

Such ships using low-flashpoint fuels shall comply with the requirements of this part in addition to any other applicable requirements of the present regulations.

2 Except as provided for in paragraphs 4 and 5, a ship, irrespective of the date of construction, including one constructed before 1 January 2009, which converts to using low-flashpoint fuels on or after 1 January 2017 shall be treated as a ship using low-flashpoint fuels on the date on which such conversion commenced.

3 Except as provided for in paragraphs 4 and 5, a ship using low-flashpoint fuels, irrespective of the date of construction, including one constructed before 1 January 2009, which, on or after 1 January 2017, undertakes to use low-flashpoint fuels different from those which it was originally approved to use before 1 January 2017 shall be treated as a ship using low-flashpoint fuels on the date on which such undertaking commenced.

4 This part shall not apply to gas carriers, as defined in regulation Vll/ 11.2:

.1 using their cargoes as fuel and complying with the requirements of the IGC Code, as defined in regulation Vll/ 11 .1; or

.2 using other low-flashpoint gaseous fuels provided that the fuel storage and distribution systems design and arrangements for such gaseous fuels comply with the requirements of the IGC Code for gas as a cargo.

5 This part shall not apply to ships owned or operated by a Contracting Government and used, for the time being, only in government non-commercial service. However, ships owned or operated by a Contracting Government and used, for the time being, only in Government non-commercial service are encouraged to act in a manner consistent, so far as reasonable and practicable, with this part.

Regulation 57

Requirements for ships using low-flashpoint fuels Except as provided in regulations 56.4 and 56.5, ships using low-flashpoint fuels shall comply with the requirements of the IGF Code.

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Unified interpretations for chapter 11-1

1 Application (Source: MSC.1/Circ.1673)

Regs. 1.1.1.1, 1.1 The expression "ships constructed before 1 January 2024" with respect to ships subject to the 1.1.1.2, 1.1.3, provisions of SOLAS regulation 11-1/1.1.1.1 should mean:

25 -1•1 .1 ships with a contract for construction date on or after 1 January 2020 but before 1 January 2024 subject to compliance with .3 below; or

.2 ships without a contract for construction, having a keel laying date, or similar stage of construction date, on or after 1 July 2020 but before 1 July 2024 subject to compliance with

.3 below; and

.3 ships with a date of delivery on or after 1 January 2024 but before 1 January 2028, provided the condition in .1 or .2 above, as applicable, is met.

1.2 The expression "Multiple hold cargo ships other than bulk carriers and tankers constructed on or after 1 January 2024" as used in SOLAS regulation 11-1/25-1 (as amended by resolution MSC.482(103)) should be interpreted as follows: "Multiple hold cargo ships other than bulk carriers and tankers constructed on or after 1 January 2024" should be subject to the definition of "ships constructed on or after 1 January 2024" in SOLAS regulation 11-1/1.1.3.2 (as amended by resolution MSC.474(102))."

2 Application (Source: MSC-MEPC.2/Circ.10)

Reg.1.3 For conversions of single-hull oil tankers to double-hull oil tankers or bulk carriers, the following should apply:

.1 Conversions of single-hull oil tankers to double-hull oil tankers or bulk carriers should be regarded as modifications of a major character for the purposes of SOLAS chapter 11-1 .

.2 Repairs, alterations and modifications of a major character include:

.1 Substantial alteration of the dimensions of a ship, for example lengthening of a ship by adding a new midbody. The new midbody should comply with SOLAS chapter 11-1 .

.2 A change of ship type, for example an oil tanker converted to a bulk carrier. Any structure, machinery and systems that are added or modified should comply with SOLAS chapter 11-1, taking into account the interpretation of SOLAS chapter 11-1 regulations as contained herein.

3 Definitions (Source: MSC.1/Circ.1362/Rev.2)

Reg. 2.14 For ships constructed on or after 21 May 2010: In determining the permeability of a space, the volume of a space should be taken as the moulded volume, i.e. the immersed volume of a space should be the underwater moulded volume of that space multiplied by the permeability.

4 Deadweight to be stated on certificates (Source: MSC.1/Circ.1573)

Reg. 2.20 Even-keel hydrostatics should be used to determine the regulatory deadweight to be entered on relevant statutory certificates.

5 Definition of the term "Lightweight" (Source: MSC.1/Circ.1539/Rev.1)

Reg. 2.21 The weight of mediums on board for the fixed fire-fighting systems (e.g. freshwater, CO 2 , dry chemical powder, foam concentrate, etc.) should be included in the lightweight and lightship condition.

6 Protective coatings of dedicated seawater (Source: MSC.1/Circ.1539/Rev.1)

ballast tanks in all types of ships and double-side skin spaces of bulk carriers Reg. 3-2 The following tanks should not be considered to be dedicated seawater ballast tanks and should, therefore, be exempted from the application and requirements of the Performance standard for protective coatings for dedicated seawater ballast tanks in all types of ships and double-side skin spaces of bulk carriers (resolution MSC.215(82)), provided the coatings applied in the tanks described in sub-paragraphs .2 and .3 below are confirmed by the coating manufacturer to be resistant to the media stored in these

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Unified interpretations for chapter II- 1

tanks and provided such coatings are applied and maintained according to the coating manufacturer's procedures .

.1 ballast tanks identified as "Spaces included in Net Tonnage" in the International Tonnage Certificate (1969);

.2 seawater ballast tanks in passenger ships also designated for the carriage of grey water or black water; and

.3 seawater ballast tanks in livestock carriers also designated for the carriage of livestock dung.

7 Protective coatings of dedicated seawater (Source: MSC-MEPC.2/Circ.10} ballast tanks in all types of ships and double-side skin spaces of bulk carriers Regs. 3-2.2 7.1 For single-hull oil tanker conversion into double-hull oil tanker, SOLAS regulation 11-1/3-2 as adopted and 3-2.4 by resolution MSC.216(82) should apply to dedicated water ballast tanks if constructed with all structural members being entirely new. If converting existing spaces into water ballast tanks with part of the existing structural members remaining in place, revised SOLAS regulation 11-1/3-2 (MSC.216(82)) need not be applied. However, dedicated seawater ballast tanks should have an efficient corrosion prevention system such as hard protective coatings or equivalent and be of light colour.

7.2 For single-hull oil tanker conversion into bulk carrier, SOLAS regulation 11-1/3-2 as adopted by resolution MSC.216(82) should apply to dedicated water ballast tanks and double-side skin spaces of bulk carriers if constructed with all structural members being entirely new. If converting existing spaces into dedicated water ballast tanks or double-side skin space of bulk carriers with part of the existing structural members remaining in place, revised SOLAS regulation 11-1/3-2 (MSC.216(82)) need not be applied. However, dedicated seawater ballast tanks should have an efficient corrosion prevention system such as hard protective coatings or equivalent and be of light colour.

8 New installation of materials containing asbestos (Source: MSC.1/Circ.1426/Rev.1)

Reg. 3-5 Administrations or recognized organizations acting on their behalf should verify that materials which contain asbestos, as prohibited under SOLAS regulation 11-1/3-5, are not installed on ships by reviewing asbestos-free declarations and supporting documentation for the structure, machinery, electrical installations and equipment covered by the SOLAS Convention, which should be provided to the Administration or recognized organization by shipyards, repair yards and equipment manufacturers, taking into account appendix 6 of the 2015 Guidelines for the development of the inventory of hazardous materials (resolution MEPC.269(68)).

9 Access to and within spaces in, and forward of, (Source: MSC-MEPC.2/Circ.10)

the cargo area of oil tankers and bulk carriers

Reg. 3-6 9.1 For single-hull oil tanker conversion into double-hull oil tanker

9.1.1 Permanent means of access contained in table 1 of the Technical provisions for means of access for inspections (resolution MSC.158(78)) need not apply. However, if, in the course of conversion, substantial new structures are added, these new structures should comply with the regulation.

9.1.2 The term "substantial new structures" means hull structures that are entirely renewed or augmented by new double bottom and/or double-side construction (e.g. replacing the entire structure within cargo area or adding a new double bottom and/or double-side section to the existing cargo area).

9.1.3 Additionally, an approved Ship Structure Access Manual should be provided.

9.2 For single-hull oil tanker conversion into bulk carrier

9.2.1 Permanent means of access contained in table 2 of the Technical provisions for means of access for inspections (resolution MSC.158(78)) need not apply. However, if, in the course of conversion, substantial new structures are added, these new structures should comply with the regulation.

9.2.2 The term "substantial new structures" means hull structures that are entirely renewed or augmented by new double bottom and/or double-side skin construction (e.g. replacing the entire structure within cargo area or adding a new double bottom and/or double-side section to the existing cargo area).

9.2.3 Additionally, an approved Ship Structure Access Manual should be provided.

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Unified interpretations for chapter 11-1

10 Application (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.1 Oil tankers

10.1 This regulation is only applicable to oil tankers having integral tanks for carriage of oil in bulk, which is contained in the definition of oil in Annex I of MARPOL. Independent oil tanks can be excluded. Regulation 11-1/3-6 should not normally be applied to an FPSO* or FSUt unless the Administration decides otherwise.

Technical background

10.2 Means of access specified in the Technical provisions contained in resolution MSC.158(78) are not specific with respect to the application to integral cargo oil tanks or also to independent cargo oil tanks. Enhanced survey programme (ESP) requirements of oil tankers have been established assuming the target cargo oil tanks are integral tanks. The means of access regulated under regulation 11-1/3-6 is for overall and close-up inspections as defined in regulation IX/1. Therefore it is assumed that the target cargo oil tanks are those of ESP, i.e. integral cargo tanks. Regulation 11-1/3-6 is applicable to new, purpose- built FPSOs or FSUs if they are subject to the scope of the 2011 ESP Code (resolution A.1049(27), as amended). Considering that the principles of the Technical provisions for means of access for inspections (resolution MSC.158(78)) recognize that permanent means of access should be considered and provided for at the design stage so that, to the maximum extent possible, they can be made an integral part of the designed structural arrangement, regulation 11-1/3-6 is not considered applicable to an FPSO/FSU that is converted from an existing tanker.

Reference

10.3 SOLAS regulation IX/1 and the 2011 ESP Code, as amended.

11 Means of access to cargo and other spaces (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.2.1 Each space for which close-up inspection is not required such as fuel oil tanks and void spaces forward of cargo area, may be provided with a means of access necessary for overall survey intended to report on the overall conditions of the hull structure.

12 Means of access to cargo and other spaces (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.2.2 12.1 Some possible alternative means of access are listed under paragraph 3.9 of the Technical provisions for means of access for inspections. Always subject to acceptance as equivalent by the Administration, alternative means such as an unmanned robot arm, ROVs+ and dirigibles with the necessary equipment of the permanent means of access for overall and close-up inspections and thickness measurements of the deck head structure such as deck transverses and deck longitudinals of cargo oil tanks and ballast tanks, should be capable of:

.1 safe operation in ullage space in a gas-free environment; and

.2 introduction into the place directly from a deck access.

Technical background

12.2 Innovative approaches, in particular the development of robots in place of elevated passageways, are encouraged and it is considered worthwhile to provide the functional requirement for the innovative approach.

13 Means of access to cargo and other spaces (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.2.3 Inspection

13.1 The means of access arrangements, including portable equipment and attachments, should be annually inspected by the crew or competent inspectors and the inspections should be recorded in Part 2 of the Ship Structure Access Manual. In addition, prior to any space examinations that utilized the permanent means of access, an inspection to confirm the condition of the permanent means of access should be recorded for each space.

* FPSO: floating production, storage and offloading facility. t FSU: floating storage unit. + ROV: remotely operated vehicle.

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Unified interpretations for chapter II- 1

Procedures

13.2 Any Company-authorized person using the means of access should assume the role of inspector and check for obvious damage prior to using the access arrangements. Whilst using the means of access, the inspector should verify the condition of the sections used by close-up examination of those sections and note any deterioration in the provisions. Should any damage or deterioration be found, the effect of such deterioration including loss of coating and wastage should be assessed as to whether the damage or deterioration affects the safety for continued use of the access. Deterioration found that is considered to affect safe use should be determined as "substantial damage" and measures should be put in place to ensure that the affected section(s) are not to be further used prior to effective repair. Substantial damage should be reported in Part 2 of the Ship Structure Access Manual.

13.3 Statutory survey of any space that contains means of access should include verification of the continued effectiveness of the means of access in that space. Survey of the means of access should not be expected to exceed the scope and extent of the survey being undertaken. If the means of access is found deficient the scope of survey should be extended if this is considered appropriate.

13.4 Records of all inspections should be established based on the requirements detailed in the ship's Safety Management System. The records should be readily available to persons using the means of access and a copy attached to the Ship Structure Access Manual. The latest record for the portion of the means of access inspected should include as a minimum the date of the inspection, the name and title of the inspector, a confirmation signature, the sections of means of access inspected, verification of continued serviceable condition or details of any deterioration or substantial damage found and repairs carried out. A file of permits issued should be maintained for verification. Inspection records of permanent means of access should be made available to classification society surveyors prior to survey.

Technical background

13.5 It is recognized that means of access may be subject to deterioration in the long term due to the corrosive environment and external forces from ship motions and sloshing of liquid contained in the tank, and mechanical damage in the cargo hold. Means of access therefore should be inspected at every opportunity of tank/space entry, but at a minimum annually. The above interpretation should be contained in a section of the Ship Structure Access Manual.

14 Safe access to cargo holds, cargo tanks, (Source: MSC.1/Circ.1572/Rev.2)

ballast tanks and other spaces Reg. 3-6.3.1 14.1 Access to a double-side skin space of bulk carriers may be either from a topside tank or double- bottom tank or from both.

14.2 The wording "not intended for the carriage of oil or hazardous cargoes" applies only to "similar compartments", i.e. safe access can be through a pump-room, deep cofferdam , pipe tunnel, cargo hold or double-hull space.

Technical background

14.3 Unless used for other purposes, the double-side skin space should be designed as a part of a large U-shaped ballast tank and such space should be accessed through the adjacent part of the tank, i.e. topside tank or double-bottom/bilge hopper tank. Access to the double-side skin space from the adjacent part rather than direct from the open deck is justified. Any such arrangement should provide a directly routed, logical and safe access that facilitates easy evacuation of the space.

15 Safe access to cargo holds, cargo tanks, (Source: MSC.1/Circ.1572/Rev.2)

ballast tanks and other spaces Reg. 3-6.3.2 15.1 A cargo oil tank of less than 35 m length without a swash bulkhead requires only one access hatch.

15.2 Where rafting is indicated in the Ship Structures Access Manual as the means to gain ready access to the under-deck structure, the term "similar obstructions" referred to in the regulation includes internal structures (e.g. webs > 1.5 m deep) which restrict the ability to raft (at the maximum water level needed for rafting of under-deck structure) directly to the nearest access ladder and hatchway to the deck. When rafts or boats alone, as an alternative means of access, are allowed under the conditions specified in the

2011 ESP Code, permanent means of access are to be provided to allow safe entry and exit. This means:

.1 access direct from the deck via a vertical ladder and small platform fitted approximately 2 m below the deck in each bay; or

.2 access to the deck from a longitudinal permanent platform having ladders to the deck in each end of the tank. The platform should, for the full length of the tank, be arranged in level with, or above, the maximum water level needed for rafting of the under-deck structure. For this purpose, the ullage corresponding to the maximum water level should not be assumed UNIFIED INTERPRETATIONS Unified interpretations for chapter 11-1 to be more than 3 m from the deck plate measured at the midspan of deck transverses and in the middle length of the tank (see figure below). A permanent means of access from the longitudinal permanent platform to the water level indicated above should be fitted in each bay (e.g. permanent rungs on one of the deck webs inboard of the longitudinal permanent platform).

• J 3.0m

0 0 ~ Orn ~

0 : .._..--, Figure 1

16 Ship Structure Access Manual (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.4.1 16.1 The access manual should address spaces listed in paragraph 3 of regulation 11-1/3-6. As a minimum the English version should be provided. The Ship Structure Access Manual should contain at least the following two parts: Part 1: Plans, instructions and inventory required by paragraphs 4.1.1 to 4.1 .7 of regulation 11-1/3-6. This part should be approved by the Administration or the organization recognized by the Administration. Part 2: Form of record of inspections and maintenance, and change of inventory of portable equipment due to additions or replacement after construction. This part should be approved for its form only at new building.

16.2 The following matters should be addressed in the Ship Structure Access Manual:

.1 the access manual should clearly cover the scope as specified in the regulations for use by crews, surveyors and port State control officers;

.2 approval/re-approval procedure for the manual , i.e. any changes of the permanent, portable, movable or alternative means of access within the scope of the regulation and the Technical provisions, are subject to review and approval by the Administration or by the organization recognized by the Administration;

.3 verification of means of access should be part of the safety construction survey for continued effectiveness of the means of access in that space which is subject to the statutory survey;

.4 inspection of means of access by the crew and/or a competent inspector of the Company as a part of regular inspection and maintenance (see interpretation 13 of regulation 11-1/3-6);

.5 actions to be taken if means of access is found unsafe to use; and

.6 in case of use of portable equipment plans showing the means of access within each space indicating from where and how each area in the space can be inspected.

17 Ship Structure Access Manual (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.4.2 17.1 Critical structural areas should be identified by advanced calculation techniques for structural strength and fatigue performance, if available, and feedback from the service history and design development of similar or sister ships.

17.2 Reference should be made to the following publications for critical structural areas, where applicable:

.1 Oil tankers: Guidance Manual for Tanker Structures by TSCF;

.2 Bulk Carriers - Guidelines for Surveys, Assessment and Repair of Hull Structures by IACS;

and

.3 Oil tankers and bulk carriers: the 2011 ESP Code (resolution A.1049(27), as amended).

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Unified interpretations for chapter II- 1

Technical background

17.3 These documents contain the relevant information for the present ship types. However, identification of critical areas for new double-hull tankers and double-side skin bulk carriers of improved structural design should be made by structural analysis at the design stage and this information should be taken into account to ensure appropriate access to all identified critical areas.

18 General technical specifications (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.5.1 18.1 The minimum clear opening of 600 mm x 600 mm may have corner radii up to 100 mm maximum. The clear opening is specified in MSC/Circ.686/Rev.1 to keep the opening fit for passage of personnel wearing a breathing apparatus. In such a case where, as a consequence of structural analysis of a given design the stress should be reduced around the opening, it is considered appropriate to take measures to reduce the stress such as making the opening larger with increased radii, e.g. 600 x 800 with 300 mm radii, in which a clear opening of 600 x 600 mm with corner radii up to 100 mm maximum fits.

Technical background

18.2 The interpretation is based upon the established Guidelines in MSC/Circ.686/Rev.1.

Reference

18.3 Paragraph 9 of the annex to MSC/Circ.686/Rev.1.

19 General technical specifications (Source: MSC.1/Circ.1572/Rev.2)

Reg. 3-6.5.2 19.1 The minimum clear opening of not less than 600 mm x 800 mm may also include an opening with corner radii of 300 mm. An opening of 600 mm in height x 800 mm in width may be accepted as an access opening in vertical structures where it is not desirable to make large openings in the structural strength aspects, i.e. girders and floors in double-bottom tanks.

19.2 Subject to verification of easy evacuation of an injured person on a stretcher, the vertical opening

850 mm x 620 mm with wider upper half than 600 mm, while the lower half may be less than 600 mm with the overall height not less than 850 mm is considered an acceptable alternative to the traditional opening of 600 mm x 800 mm with corner radii of 300 mm.

I 21850 OFF C.L. I

Figure 2

19.3 If a vertical opening is at a height of more than 600 mm steps then handgrips should be provided.

In such arrangements it should be demonstrated that an injured person can be easily evacuated.

Technical background

19.4 The interpretation is based upon the established Guidelines in MSC/Circ.686/Rev.1 and an innovative design is considered for easy access by humans through the opening.

Reference

19.5 Paragraph 11 of the annex to MSC/Circ.686/Rev.1.

20 Towing and mooring equipment (Source: MSC.1/Circ.1362/Rev.2)

Reg. 3-8 20.1 The expression "all ships" in SOLAS regulation 11-1/3-8.9 means ships constructed before, on or after 1 January 2009 in accordance with SOLAS regulation 11-1/1.1.3.2.

20.2 Irrespective of the scope of review by the Administration or a recognized organization (RO), as clarified below, for ships covered by the application provisions described in SOLAS regulations 11-1/3-8.1 and 11-1/3-8.2, as amended by resolution MSC.474(102), owners and designers should comply with the:

.1 Revised guidance on shipboard towing and mooring equipment (MSC.1/Circ.1175/Rev.1);

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Unified interpretations for chapter 11-1

.2 Guidelines on the design of mooring arrangements and the selection of appropriate mooring equipment and fittings for safe mooring (MSC.1/Circ.1619); and

.3 Guidelines for inspection and maintenance of mooring equipment including lines (MSC.1/Circ.1620), footnoted in SOLAS regulation 11-1/3-8, in its entirety, and ensure that appropriate measures are taken to mitigate any occupational risks arising from deviations.

20.3 While applying the requirements of SOLAS regulation 11-1/3-8.4 to regulation 11-1/3-8.6 and SOLAS regulation 11-1/3-8.8, for ships of less than 3,000 gross tonnage, the following is recommended:

.1 the "Towing and mooring arrangements plan" should be provided for information, where the winch brake holding capacities should be included in addition to the information provided in section 5 (Towing and mooring arrangements plan) of the annex to MSC.1/Circ.1175/Rev.1. A technical specification document of the mooring lines supplied with the ship should be provided for information. The manufacturers' recommended minimum diameter D of each fitting in contact with the mooring lines and the line design break force {LDBF) of the mooring lines should be included in the document;

.2 for confirmation of the appropriate selection of mooring line, the properties of mooring lines related to LDBF and bend radius (D/d ratio) should be submitted to the Administration or the RO. A warning should be provided that the wear rate of lines may be higher for lower diameter (paragraph 5.6 of MSC.1/Circ.1620); and

.3 at delivery of the ship, the Administration or the RO should confirm that the Towing and mooring arrangements plan is provided on board.

20.4 While applying the requirements of SOLAS regulation 11-1/3-8.4 to regulation 11-1/3-8.6 and the SOLAS regulation 11-1/3-8.7, for ships of 3,000 gross tonnage and above, the following is recommended in addition to those specified under paragraph 3 of this interpretation:

.1 a document should be provided by the designer for information and as a supplement to the towing and mooring arrangements plan, confirming that MSC.1 /Circ.1619 has been considered. The document should explicitly state that the deviations, if any, were unavoidable;

.2 deviations should be recorded (paragraph 6.1 of MSC.1/Circ.1619), and justification and suitable safety measures should be provided (paragraph 6.2 of MSC.1 /Circ.1619) in the supplement to the towing and mooring arrangements plan. A reference to the supplement should be included in the towing and mooring arrangements plan (paragraph 6.3 of MSC.1 /Circ.1619);

.3 if deviations are not found necessary, and the supplement is not needed, then this should be mentioned explicitly in the towing and mooring arrangements plan;

.4 the mooring winches' brake holding capacities should be less than 100% of the ship design minimum breaking load (MBLso) (paragraphs 5.2.3.3 and 5.2.4 of MSC.1/Circ.1619). The winches should be fitted with brakes that allow for the reliable setting of the brake rendering load; and

.5 at delivery of the ship, the Administration or the RO should confirm that the towing and mooring arrangements plan and the supplement describing deviations and suitable safety measures are provided on board.

20.5 While applying the requirements of SOLAS regulation 11-1/3-8.9, the following should be complied with, and compliance should be confirmed by the surveyor at the initial survey for new ships or at the first annual survey for the issuance of the Cargo Ship Safety Construction Certificate or renewal survey for the issuance of the Passenger Ship Safety Certificate after 1 January 2024 for existing ships:

.1 procedures for mooring operations, inspection and maintenance of mooring equipment, including mooring lines, should be established and available on board (paragraph 3.1 of MSC.1/Circ.1620), taking into account industry practices (section 7 of MSC.1/Circ.1620);

.2 procedures to allow the identification and control of mooring lines, tails and associated attachments should be established and available on board (paragraph 3.3 of MSC.1/Circ.1620);

.3 the periodic inspection of mooring lines, mooring line tails and associated attachments should be included in the on board maintenance plan or equivalent maintenance management system (paragraph 4.1.1 of MSC.1/Circ.1620);

.4 manufacturers' criteria for replacement of mooring lines should be available (paragraph 4.3.1 of MSC.1/Circ.1620);

.5 records of the original design concept, equipment, arrangements and specifications should be available on board (paragraph 4.4.4 of MSC.1/Circ.1620). For ships the keels of which were laid before 1 January 2007 and without appropriate documentation, owners may establish the MBLso for mooring based on the safe working load of mooring equipment provided on board. If no safe working load is specified, then owners are advised to check the strength UNIFIED INTERPRETATIONS Unified interpretations for chapter II- 1 of mooring equipment and their supporting hull structure based on MSC.1/Circ.1175/Rev.1 and determine M8L80 based on actual capacity of the equipment and their supporting hull structure on board. Manufacturers' test certificates for mooring lines, joining shackles and synthetic tails should be kept on board and properly linked back to the equipment, if available (paragraph 6.2 of MSC.1/Circ.1620); and

.6 a document should be provided on board for gathering the information above and describe how the information listed above is filed and collected.

20.6 While applying the requirements of SOLAS regulation 11-1/3-8.9, the following should be complied with, and the compliance should be confirmed by the surveyor at the periodical survey for endorsement/ issue of the Cargo Ship Safety Construction Certificate or the renewal survey for the Passenger Ship Safety Certificate after 1 January 2024 for existing ships:

.1 the records of inspection and maintenance of mooring equipment and inspection and replacement of mooring lines, since the last periodical survey, should be kept updated and available on board (paragraphs 4.4.3 and 6.1 of MSC.1/Circ.1620).

21 Goal-based ship construction standards (Source: MSC.1/Circ.1637)

for bulk carriers and oil tankers

Reg. 3-10 21.1 For the purpose of defining the category of a ship under SOLAS regulation 11-1/3-10, a ship for which the building contract (or keel laying) occurred, and scheduled delivery date was, before the dates specified in this regulation, but where the delivery has been subject to delay beyond the specific date due to unforeseen circumstances beyond the control of the builder and the owner, may be accepted by the Administration as a ship delivered before the date of delivery specified in this regulation. The treatment of such ships should be considered by the Administration on a case-by-case basis, bearing in mind the particular circumstances.

21.2 It is important that ships accepted by the Administration under the provisions of paragraph 21.1 above should also be accepted as such by port States. In order to ensure this, the following practice is recommended to Administrations when considering an application for such a ship:

.1 the Administration should thoroughly consider applications on a case-by-case basis, bearing in mind the particular circumstances. In doing so in the case of a ship built in a foreign country, the Administration may require a formal report from the authorities of the country in which the ship was built, stating that the delay was due to unforeseen circumstances beyond the control of the builder and the owner;

.2 when a ship is accepted by the Administration under the provisions of paragraph 21.1 above, the delivery date annotated on the Cargo Ship Safety Construction Certificate or Cargo Ship Safety Certificate should be footnoted to indicate that the ship is accepted by the Administration under the unforeseen delay in delivery provisions of this interpretation; and

.3 the Administration should report to the Organization the identity of the ship and the grounds on which the ship has been accepted under the unforeseen delay in delivery provisions of this interpretation.

22 Subdivision and stability (Source: MSC-MEPC.2/Circ.10)

Part 8 22.1 For single-hull oil tanker conversion into double-hull oil tanker

Oil tankers complying with damage stability requirements contained in Annex I to MARPOL 73/78 (except for combination carriers with type 8 freeboards) may be excluded from the damage stability requirements contained in SOLAS chapter 11-1, part 8-1.

22.2 For single-hull oil tanker conversion into bulk carrier

22.2.1 A bulk carrier which is assigned a 8 reduced freeboard complying with damage stability requirements contained in regulation 27 of the 1966 Load Line Convention, and resolutions A.320(1X) and A.514(13); or regulation 27 of the 1988 Load Line Protocol, may be excluded from the damage stability requirements contained in SOLAS chapter 11-1, part 8-1.

22.2.2 For a bulk carrier which is assigned a 8 freeboard, SOLAS chapter 11-1, parts 8 and 8-1 should be applied.

                                                                                                                UNIFIED
                                                                                                            INTERPRETATIONS

                                                                                          Unified interpretations for chapter 11-1


                 23     Intact stability                                                        (Source: MSC.1/Circ.1362/Rev.2)
Regs. 5.4        Definition of lightweight calculation
and 5.5          23.1 For the purposes of this interpretation, the term "lightweight calculation" means a detailed
                 calculation of weights on and weights off a ship, resulting from all alterations to the ship since the date
                 of the last approved inclining test, to determine the adjusted lightship properties. Lightship properties
                 include weights and the centre of gravity. The documented weights and their centres of gravity should be
                 verified on board/on-site by the attending class surveyor.
                 23.2 When weights are added, removed or relocated, the final cumulative change is to be compared
                 with the last approved inclining test.
                 23.3 "Lightweight survey" is defined in the International Code on Intact Stability 2008, paragraph 2.24.

                 Definition of stability information
                 23.4 "Stability information" includes any document (whether on paper or electronic) or electronic means
                 of calculation of stability which includes lightship properties. This could include, but is not limited to, the
                 approved stability book, computer software for onboard calculation of stability, the approved strength
                 book and the loading instrument.

                Amendment of stability information in conjunction with alterations of lightship properties
                 23.5 If the lightweight calculation , regardless of keel laying date, shows a deviation in lightweight mass,
                 or the longitudinal or vertical position of the centre of gravity:
                        .1    beyond any of the tolerance limits specified in explanatory note 1 to SOLAS regulation 11-1/5.4
                              (resolutions MSC.429(98)/Rev.1 and Rev.2), then the ship should be re-inclined and the
                              stability information, as defined above, should be updated to reflect the lightship properties
                              derived from the inclining test and should be approved;
                        .2     within the tolerance limits specified in the explanatory note 1 and exceeding any of the deviations
                               specified in explanatory note 2 to SOLAS regulation 11-1/5.4 (resolutions MSC.429(98)/Rev.1
                               and Rev.2), then the stability information should be updated to reflect the lightship properties
                               derived from the lightweight calculation and should be approved; or
                        .3    within the tolerance limits specified in explanatory note 2 to SOLAS regulation 11-1/5.4
                              (resolutions MSC.429(98)/Rev.1 and Rev.2), then a copy of the endorsed lightweight calculation
                              report should be provided on board for future reference with no further amendments required
                              to the stability information. However, even if addition, removal or relocation of any weight
                              results in lightship particulars being within tolerable limits, that weight should still be noted
                              and the "constant" adjusted for lightweight calculation in the stability information for all future
                              references and calculations.
                 23.6 A summary of paragraph 23.5 of this interpretation is provided in the following table. Where stability
                 information is to be updated , it should be approved and provided to the master with the instruction that
                 it should now be used for all stability calculations.

                          Scenario, as calculated                 Requirement              Update of stability information
                         by lightweight calculation             for inclining test
                  Lightweight change > 2%                                 Yes        Yes, using new incline result
                  LCG* change > 1% of L                                   Yes        Yes, using new incline result
                  (either forward or aft)
                  VCG* change > 1%                                        Yes        Yes, using new incline result
                  1% < Lightweight change::; 2%                           No         Yes, using lightweight calculation
                  0.5% of L < LCG change:::= 1% of L                      No         Yes, using lightweight calculation
                  (either forward or aft)
                  0.5% < VCG change::; 1%                                 No         Yes, using lightweight calculation
                  Lightweight change:::= 1%                               No         No
                  LCG* change :::= 0.5% of L                              No         No
                  (either forward or aft)
                  VCG* change :::= 0.5%                                   No         No


* LCG: longitudinal centre of gravity; VCG: vertical centre of gravity.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter II- 1

23.7 Lightship properties should be consistent in all documents which use them, e.g. loading manual, stability manual and computer data.

23.8 A change in lightweight will result in a change in deadweight unless there is an associated change in freeboard. The consequences of the change could have an impact on compliance with other regulations, e.g. MARPOL Annex VI.

24 Stability information to be supplied to the master (Source: MSC.1/Circ.1653)

Reg. 5-1 24.1 The ship should be supplied with comprehensive stability information which takes into account timber deck cargo. Such information shall enable the master to rapidly and simply obtain accurate guidance as to the stability of the ship under varying conditions of service and, as required in SOLAS regulation 11-1/5-1, it shall include, among other damage stability-related issues, a curve of minimum operating metacentric height (GM) versus draught or maximum allowable vertical centre of gravity (KG) versus draught which covers the requirements of SOLAS regulation 11-1/5-1.2.1.

24.2 To ensure that the buoyancy of the timber deck cargo can be justifiably credited in damage stability calculations, the integrity of the lashed timber deck cargo should comply with the following:

.1 the timber deck cargo should be stowed in accordance with the provisions of paragraph 2.9 of the Code of safe practice for ships carrying timber deck cargoes, 2011 (resolution A.1048(27) and Corr.1);

.2 the timber deck cargo should be secured by lashings and/or uprights; and

.3 lashings and uprights should comply with the provisions of paragraph 2.10 of the Code of safe practice for ships carrying timber deck cargoes, 2011 (resolution A.1048(27) and Corr.1).

24.3 The height and extent of the timber deck cargo should be in accordance with paragraph 3.3.2 of chapter 3 of part A of the International Code on Intact Stability, 2008 and should be at least stowed to the standard height of one superstructure.

24.4 The permeability of the timber deck cargo should be not less than 25% of the volume occupied by the cargo up to one standard superstructure.

24.5 Unless instructed otherwise by the Administration , the stability information for ships with timber deck cargoes should be supplemented by additional curve(s) of limiting GM (or KG) covering the timber draught range.

24.6 The above-described curve(s) applicable for conditions with timber deck cargo should be developed as described in SOLAS regulation 11-1/5-1.4, considering the timber deck cargo at the deepest timber subdivision draught and at the partial timber subdivision draught only.

24.7 The limiting GM should be varied linearly between the deepest timber subdivision draught, and between the partial timber subdivision draught and the light service draught, respectively. Where timber freeboards are not assigned, the deepest and partial draughts should relate to the summer load line.

24.8 When considering the vertical extent of damage, the upper deck may be regarded as a horizontal subdivision (in accordance with SOLAS regulation 11-1/7-2.6.1). Thus, when calculating damage cases which are limited vertically to the upper deck with the corresponding v-factor, the timber deck cargo may be considered to remain buoyant with an assumed permeability of 0.25 at the deepest and partial draught. For damage extending above the upper deck the timber deck cargo buoyancy in way of the damage zone should be ignored.

25 Calculation of the factors; (Source: MSC.1/Circ.1539/Rev.1)

Reg. 7-2 In applying 0v, openings which cannot be or are incapable of being closed weathertight include ventilators (complying with regulation 19(4) of the International Convention on Load Lines, 1966) that for operational reasons have to remain open to supply air to the engine-room, emergency generator room or closed ro-ro and vehicle spaces (if the same is considered buoyant in the stability calculation or protecting openings leading below) for the effective operation of the ship. Where it is not technically feasible to treat some closed ro-ro and vehicle space ventilators as unprotected openings, Administrations may allow an alternative arrangement that provides an equivalent level of safety.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter 11-1

26 Subdivision, watertight and weathertight integrity- (Source: MSC.1/Circ.1572/Rev.2)

Stability management Regs. 13, 26.1 Doors in watertight bulkheads of passenger ships and cargo ships ~~-~• 15 d~~ 7• This interpretation pertains to doors* located in way of the internal watertight subdivision boundaries and - an the external watertight boundaries necessary to ensure compliance with the relevant subdivision and damage stability regulations. This interpretation does not apply to doors located in external boundaries above equilibrium or intermediate waterplanes. The design and testing requirements for watertight doors vary according to their location relative to the 1) equilibrium waterplane or intermediate waterplane at any stage of assumed flooding, and/or 2) bulkhead deck or freeboard deck.

26.1.1 Definitions For the purpose of this interpretation the following definitions apply:

26.1.1.1 Watertight: Capable of preventing the passage of water in any direction under a design head.

The design head for any part of a structure should be determined by reference to its location relative to the bulkhead deck or freeboard deck, as applicable, or to the most unfavourable equilibrium/intermediate waterplane, in accordance with the applicable subdivision and damage stability regulations, whichever is the greater. A watertight door is thus one that will maintain the watertight integrity of the subdivision bulkhead in which it is located.

26.1.1.2 Equilibrium waterplane: The waterplane in still water when, taking account of flooding due to an assumed damage, the weight and buoyancy forces acting on a ship are in balance. This relates to the final condition when no further flooding takes place or after cross-flooding is completed.

26.1.1.3 Intermediate waterplane: The waterplane in still water, which represents the instantaneous floating position of a ship at some intermediate stage between commencement and completion of flooding when, taking account of the assumed instantaneous state of flooding, the weight and buoyancy forces acting on a ship are in balance.

26.1.1.4 Sliding door or rolling door: A door having a horizontal or vertical motion generally parallel to the plane of the door.

26.1.1.5 Hinged door: A door having a pivoting motion about one vertical or horizontal edge.

26.2 Structural design Doors and their frames should be of approved design and substantial construction in accordance with the requirements of the Administration and should preserve the strength of the subdivision bulkheads in which they are fitted.

26.3 Operation mode, location and outfitting Doors should be fitted in accordance with all requirements regarding their operation mode, location and outfitting, i.e. provision of controls, means of indication, etc., as shown in table 1 below. This table should be read in conjunction with paragraphs 26.3.1 to 26.5.4 below.

26.3.1 Frequency of use while at sea

26.3.1.1 Normally closed: Kept closed at sea but may be used if authorized. To be closed again after use.

26.3.1.2 Permanently closed: The time of opening such doors in port and of closing them before the ship leaves port should be entered in the logbook. Should such doors be accessible during the voyage, they should be fitted with a device to prevent unauthorized opening.

26.3.1.3 Used: Kept closed but may be opened during navigation when authorized by the Administration to permit the passage of passengers or crew, or when work in the immediate vicinity of the door necessitates it being opened. The door should be immediately closed after use.

26.3.2 Type Power operated, sliding or rollingt POS Power operated, hinged POH Sliding or rolling S Hinged H

* Doors in watertight bulkheads of small cargo ships, not subject to any statutory subdivision and damage stability requirements, may be hinged quick-acting doors arranged to open out of the major space protected. They should be constructed in accordance with the requirements of the Administration and have notices affixed to each side stating: "To be kept closed at sea". t Rolling doors are technically identical to sliding doors.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter II- 1

26.3.3 Control

26.3.3.1 Local 26.3.3.1.1 All doors, except those which should be permanently closed at sea, should be capable of being opened and closed by hand (and by power, where applicable) locally,* from both sides of the doors, with the ship listed to either side.

26.3.3.1.2 For passenger ships, the angle of list at which operation by hand should be possible is 15°.

26.3.3.1.3 For cargo ships, the angle of list at which operation by hand should be possible is 30°.

26.3.3.2 Remote Where indicated in table 1, doors should be capable of being remotely closed by power from the bridget for all ships, and also by hand from a position above the bulkhead deck for passenger ships, as required by regulation 11-1/13.7.1.4.+ Where it is necessary to start the power unit for operation of the watertight door, means to start the power unit should also be provided at remote control stations. The operation of such remote control should be in accordance with regulations 11-1/13.8.1 to 11-1/13.8.3.+ For tankers, where there is a permanent access from a pipe tunnel to the main pump room, in accordance with regulation 11-2/4.5.2.4 the watertight door should be capable of being manually closed from outside the main pump-room entrance in addition to the requirements above.

26.3.4 Indication §

26.3.4.1 Where shown in table 1, position indicators should be provided at all remote operating positions for all ships and provided locally on both sides of the internal doors for cargo ships, to show whether the doors are open or closed and, if applicable, with all dogs/cleats fully and properly engaged.

26.3.4.2 The door position indicating system should be of self-monitoring type and the means for testing of the indicating system should be provided at the position where the indicators are fitted.

26.3.4.3 A diagram showing the location of the door and an indication to show its position should be provided at the central operating console located at the navigation bridge. A red light should indicate the door is in the open position and a green light should indicate the door is in the closed position. When the door is closed from this remote position, the red light should flash when the door is in an intermediate position. This applies to passenger ships and cargo ships.

26.3.4.4 Special care should be taken in order to avoid potential danger when passing through the door.

Signboard/instructions should be placed in way of the door advising how to act when the door is in "doors closed" mode.

26.3.5 Alarms§

26.3.5.1 For passenger ships, failure of the normal power supply of the required alarms should be indicated by an audible and visual alarm at the central operating console at the navigation bridge. For cargo ships, failure of the normal power supply of the required alarms should be indicated by an audible and visual alarm at the navigation bridge.

26.3.5.2 All door types, including power-operated sliding watertight doors, which are capable of being remotely closed should be provided with an audible alarm, distinct from any other alarm in the area, which will sound whenever such a door is remotely closed. For passenger ships the alarm should sound for at least 5 seconds but not more than 10 seconds before the door begins to move and should continue sounding until the door is completely closed. In the case of remote closure by hand operation, an alarm should sound only while the door is actually moving.

26.3.5.3 In passenger areas and areas of high ambient noise, the audible alarms should be supplemented by visual signals at both sides of the doors.

26.3.5.4 All watertight doors, including sliding doors, operated by hydraulic door actuators, either a central hydraulic unit or an independent hydraulic unit for each door should be provided with a low fluid level alarm or low gas pressure alarm, as applicable, or some other means of monitoring loss of stored

• Applicable from 1 January 2020 to 1 January 2024: arrangements should be in accordance with regulation 11-1/13.7.1.4 and 11-1/13.7.1.5 for passenger ships and regulation 11-1/13-1.2 for cargo ships. SOLAS regulation 11-1/13 was amended by resolution MSC.474(102), applicable from 1 January 2024. t Applicable from 1 January 2020 to 1 January 2024: arrangements should be in accordance with regulation 11-1/13.7.1.5 for passenger ships and 11-1/13-1.2 for cargo ships. SOLAS regulation 11-1/13 was amended by resolution MSC.474(102), applicable from

1 January 2024.

t Applicable from 1 January 2020 to 1 January 2024; SOLAS regulation 11-1/13 was amended by resolution MSC.474(102), applicable from 1 January 2024 § Refer to regulations 11-1/13, 13-1, 15-1 and 17-1, IEC 60092-504, and the Code on Alerts and Indicators, 2009 (resolution A.1021(26)).

UNIFIED INTERPRETATIONS

Unified interpretations for chapter 11-1

energy in the hydraulic accumulators. For passenger ships, this alarm should be both audible and visible and should be located at the central operating console at the navigation bridge. For cargo ships, this alarm should be both audible and visible and should be located at the navigation bridge.

26.3.6 Notices As shown in table 1, doors which are normally closed at sea, but are not provided with means of remote closure, should have notices fixed to both sides of the doors stating: "To be kept closed at sea". Doors which should be permanently closed at sea should have notices fixed to both sides stating: "Not to be opened at sea".

26.3.7 Location For passenger ships the watertight doors and their controls should be located in compliance with regulations 11-1/13.5.3 and 11-1/13.7.1.2.2.*

26.4 Fire doors

26.4.1 Watertight doors may also serve as fire doors but need not be fire-tested if fitted on cargo ships or if fitted below the bulkhead deck on passenger ships. However, such doors fitted above the bulkhead deck on passenger ships should be tested to the Fire Test Procedures (FTP) Code in accordance with the fire rating of the division they are fitted in. These doors should also comply with the means of escape provisions of regulation 11-2/13. If it is not practicable to ensure self-closing, means of indication on the bridge showing whether these doors are open or closed and a notice stating "To be kept closed at sea" can be an alternative to self-closing.

26.4.2 Where a watertight door is located adjacent to a fire door, both doors should be capable of independent operation, remotely if required by regulations 11-1/13.8.1 to 11-1/13.8.3* and from both sides of each door.

26.5 Testing

26.5.1 Doors which become immersed by an equilibrium or intermediate waterplane or are below the freeboard or bulkhead deck should be subjected to a hydrostatic pressure test.

26.5.2 For large doors intended for use in the watertight subdivision boundaries of cargo spaces, structural analysis may be accepted in lieu of pressure testing. Where such doors utilize gasket seals, a prototype pressure test to confirm that the compression of the gasket material is capable of accommodating any deflection revealed by the structural analysis should be carried out.

26.5.3 Doors above freeboard or bulkhead deck, which are not immersed by an equilibrium or intermediate waterplane but become intermittently immersed at angles of heel in the required range of positive stability beyond the equilibrium position, should be hose tested.

26.5.4 Pressure testing

26.5.4.1 The head of water used for the pressure test should correspond at least to the head measured from the lower edge of the door opening, at the location in which the door should be fitted in the ship, to the bulkhead deck or freeboard deck, as applicable, or to the most unfavourable damage waterplane, if that be greater. Testing may be carried out at the factory or other shore-based testing facility prior to installation in the ship.

26.5.4.2 Leakage criteria 26.5.4.2.1 The following acceptable leakage criteria should apply: Doors with gaskets No leakage Doors with metallic sealing Maximum leakage 1 L/min 26.5.4.2.2 Limited leakage may be accepted for pressure tests on large doors located in cargo spaces employing gasket seals or guillotine doors located in conveyor tunnels, in accordance with the following:t Leakage rate (L/min) = (P +6 !i: 2)h 3 where P perimeter of door opening (metres) h = test head of water (metres)

* Applicable from 1 January 2020 to 1 January 2024; SOLAS regulation 11-1/13 was amended by resolution MSC.474(102), applicable from 1 January 2024. t Published in the ASTM F1196, Standard Specification for Sliding Watertight Door Assemblies and referenced in the Title 46 US Code of Federal Regulations 170.270 Door design, operation, installation, and testing.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter II- 1

26.5.4.2.3 However, in the case of doors where the water head taken for the determination of the scantling does not exceed 6.1 m, the leakage rate may be taken as equal to 0.375 L/min if this value is greater than that calculated by the above-mentioned formula.

26.5.4.3 For doors of passenger ships which are used at sea and which become submerged by the equilibrium or intermediate waterplane, a prototype test should be conducted, on each side of the door, to check the satisfactory closing of the door against a force equivalent to a water height of at least 1 m above the sill on the centre line of the door.*

26.5.5 Hose testing after installation All watertight doors should be subject to a hose testt after installation in a ship. Hose testing should be carried out from each side of a door unless, for a specific application, exposure to floodwater is anticipated only from one side. Where a hose test is not practicable because of possible damage to machinery, electrical equipment insulation or outfitting items, it may be replaced by means such as an ultrasonic leak test or an equivalent test.

* Arrangements for passenger ships should be in accordance with regulation 11-1/13.5.2. t Refer to IACS URS 14.2.3 IACS Reg. 1996/Rev.2, 2001.

flJ                                 Table 1 - Doors in internal watertight bulkheads and external watertight boundaries in passenger ships and cargo ships
0
r-
►       A.     Doors in internal watertight bulkheads
flJ
("')         Position relative to            1                        2                             4                                           7
                                                                                       3                            5               6                                8
0               bulkhead or           SOLAS Regulation         Frequency of use      Type        Remote         Remote         Audible or     Notice              Comments
zVl           freeboard deck                                     while at sea                    closure       indication     visual alarm
0
C
0       I.      Passenger ships
~
m                                   11-1/10, 13.4*, 13.5.1,
0                                                                                                                                                      For doors that are used,
                                    13.5.2, 13.6, 13.7.1,                                                                           Yes
m                                                              Used                   POS          Yes             Yes                          No     see 11-1/22.3 and
        A.      Below               13.8.1, 13.8.2, 16.2,                                                                         (local)
0                                                                                                                                                      MSC.1/Circ.1564
=i                                  22.1, 22.3 and 22.4
6                                   11-1/10, 13.9.1, 13.9.2,
z                                   14.2, 16.2, 22.2 and
                                                               Permanently
                                                                                      S, H         No              No               No          Yes    See Notes 2 + 3 + 4
N                                                              closed
                                    22.5
8
.i:..                               11-1/10, 16.2, 17.1 and                          POS,          Yes             Yes              Yes         No     See Note 5
                                    22.3                                             POH                                          (local)
                                                               Used                   S, H         No              Yes              No          Yes    See Note 1

        B.      Ator above          11-1/17-1.1.1, 17-1.1.2,                                                                        Yes                Doors giving access to below the
                                                                                      S,H          No              Yes                          Yes
                                    17-1.1.3, 23.6 and 23.8                                                                      (remote)              ro-ro deck
                                    11-1/17-1.1.1, 17-1.1.2,
                                                               Permanently                                                          Yes
                                    17-1.1.3, 22.7 and 23.3                           S, H         No              Yes                          Yes    See Notes 1 + 2 + 3
                                                               closed                                                            (remote)
                                    to 23.5




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                                                                                                                                                                                          ro
                                                                                                                                                                                          ""'
                                                                                                                                                                                          -0


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.....                                                                                                                                                                                     ~
.....
.i:..
        * Applicable from 1 January 2020 to 1 January 2024; SOLAS regulation 11-1/13 was amended by resolution MSC.474(102), applicable from 1 January 2024.                              .....
                                                                                                                                                                                           I

_.
~             Position relative to              1                           2                3             4                5                6            7                   8                       ~
                 bulkhead or
               freeboard deck
                                         SOLAS Regulation            Frequency of use
                                                                       while at sea
                                                                                            Type        Remote
                                                                                                        closure
                                                                                                                        Remote
                                                                                                                       indication
                                                                                                                                        Audible or
                                                                                                                                       visual alarm
                                                                                                                                                        Notice             Comments
                                                                                                                                                                                                      ~
                                                                                                                                                                                                      0..
                                                                                                                                                                                                      :5·
                                                                                                                                                                                                       (D
          II.    Cargo ships                                                                                                                                                                          -:a
                                       11-1/10, 13-1.2, 16.2                                 POS           Yes             Yes               Yes          No
                                                                                                                                                                                                      ril
                                                                    Used                                                                                                                               fti"
                                       and 22.3                                                                                            (local)                                                    g.
                                                                                                                                                                                                      :::i
                                       11-1/10, 13-1.3, 16.2,
                                                                    Normally closed
                                                                                             S, H          No              Yes               No           Yes    See Note 1                           "'a'
          A.     Below                 22.3 and 24.4
                                                                                                                                                                                                       ""'g_
                                       11-1/10, 13-1.4, 16.2,
                                       24.3 and 24.4                                                                                                                                                  ~
                                                                    Permanently                                                                                                                        (D
                                       11-1/10, 13-1.4, 13-1.5,                              S, H          No               No               No           Yes    See Notes 2 + 3                       ""'=;:::
                                                                    closed
                                       16.2, 22.2, 24.3 and
                                       24.4
                                                                                                                                                                                                      ~
                                       11-1/10, 13-1.2, 16.2        Used                     POS           Yes             Yes               Yes          No
                                       and 22.3                                                                                            (local)
                                       11-1/10, 13-1.3, 16.2,
          B.     Ator above                                         Normally closed          S,H           No              Yes               No           Yes    See Note 1
                                       22.3 and 24.4
                                       11-1/10, 13-1.4, 13-1.5,     Permanently
                                                                                             S,H           No               No               No           Yes    See Notes 2 + 3
                                       16.2, 24.3 and 24.4          closed

          Notes:

                If hinged, this door should be of quick acting or single action type.

CJl I     2     The time of opening such doors in port and closing them before a voyage commences should be entered in the logbook, in case of doors in watertight bulkheads subdividing cargo
0
r-
                spaces.

~I        3     Doors should be fitted with a device which prevents unauthorized opening.

81        4     Passenger ships which have to comply with regulation 11-1/14.2 require an indicator on the navigation bridge to show automatically when each door is closed and all door fastenings
zVl             are secured.

01
r
          5     Refer to the explanatory note to regulation 11-1/17.1 regarding sliding watertight doors with a reduced pressure head and sliding semi-watertight doors.
0
~
m
0
m
0
=l
B
z
N
0
N
.j:::..

flJ     B.     Doors in external watertight boundaries below equilibrium or intermediate waterplane
0
r-
►            Position relative to              1                          2                 3        4               5                6          7                   8
flJ
                bulkhead or             SOLAS Regulation           Frequency of use        Type   Remote         Remote          Audible or    Notice             Comments
("')
              freeboard deck                                         while at sea                 closure       indication      visual alarm
0
zVl
0       I.      Passenger ships
C
0       A.      Below                 11-1/15.9, 22.6 and         Permanently
~
m
                                      22.12                       closed
                                                                                           S, H      No             No               No         Yes     See Notes 2 + 3
0
m                                     11-1/17.1 and 22.3
0                                                                                          S, H      No             Yes              No         Yes     See Note 1
                                      MSC.Circ.541
=i                                                                Normally closed
6                                     11-1/17-1.1.1, 17-1.1.2,                                                                     Yes                  Doors giving access to below
        B.      Ator above                                                                 S, H      No             Yes                         Yes
z                                     17-1.3, 23.6 and 23.8                                                                      (Remote)               ro-ro deck
N
                                      11-1/17-1.1.1, 17-1.2,      Permanently                                                      Yes
8
.i:..                                 17-1.3, 23.3 and 23.5       closed
                                                                                           S, H      No             Yes
                                                                                                                                 (Remote)
                                                                                                                                                Yes     See Notes 2 + 3

        II.     Cargo ships
                                      11-1/15.9, 15-1.2, 15-1.3, Permanently               S, H      No             Yes              No         Yes     See Notes 2 + 3
        A.      Below                 15-1.4, 22.6, 22.12 and closed
                                      24.1
                                      11-1/15-1.2                 Normally closed          S, H      No             Yes              No         Yes     See Note 1
        B.      Ator above            11-1/15-1.2 and 15-1.4      Permanently
                                                                                           S, H      No             Yes              No         Yes     See Notes 2 + 3
                                                                  closed

        Notes:

               If hinged, this door should be of quick acting or single action type.

        2      The time of opening such doors in port and closing them before a voyage commences should be entered in the logbook.                                                     C
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        3      Doors should be fitted with a device which prevents unauthorized opening.                                                                                               ni"
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UNIFIED INTERPRETATIONS

Unified interpretations for chapter II- 1

27 Openings in watertight boundaries below the (Source: MSC.1/Circ. 1362/Rev.2)

bulkhead deck in passenger ships Reg. 13.2.3 27.1 Any penetration used for the passage of heat-sensitive piping systems through a watertight bulkhead or deck on a passenger ship under SOLAS regulation 11-1/13.2.3 should be tested with the heat-sensitive piping and should be type-approved for watertight integrity as per paragraphs 4 and 5 of the explanatory notes to regulation 11-1/13.2.3 contained in the annex of resolutions MSC.429(98)/Rev.1 and Rev.2, as applicable, after the fire test.

27.2 SOLAS regulation 11-1/13.2.3 should be applicable to heat-sensitive piping systems and should not be applied to cable penetrations in watertight bulkheads and decks.

28 Integrity of the hull and superstructure, (Source: MSC. 1/Circ. 1571)

damage prevention and control on ro-ro passenger ships Reg. 28.1 Stern, bow and side doors of large dimensions, when manual devices would not be readily 17-1.1.1 accessible, should be normally secured by means of power systems.

28.2 Alternative means of securing should also be provided for emergency use in case of failure of the power systems.

28.3 In ro-ro passenger ships constructed before 1 July 1997, all access doors or hatchways to spaces below the ro-ro deck, which may be used at sea, should have sills or coamings not less than 380 mm in height above the ro-ro deck, and should be provided with doors or covers considered weathertight in relation to their position; refer to SOLAS regulation 11-1/20-2.*

28.4 For ro-ro passenger ships constructed on or after 1 July 1997 but before 1 January 2009, refer to SOLAS regulation 11-1/20-2.*

28.5 The ro-ro deck, referred to in paragraph 28.3 above, is the deck above which the stern, bow or side doors are fitted , or the first deck above the load waterline.

29 Flooding detection systems for passenger ships (Source: MSC.1/Circ.1539/Rev. 1)

carrying 36 or more persons Reg. 22-1 For passenger ships carrying 36 or more persons and subject to SOLAS regulation 11-1 /8-1, the Safe Return To Port (SRTP) requirements of SOLAS regulation 11-2/21.4 apply to both:

.1 the flooding detection systems in the spaces as defined in paragraph 6 of MSC.1/Circ.1291;

and

.2 the liquid level monitoring systems, which are used as, or replace, the flooding detection systems, as specified in paragraph 7 of MSC.1/Circ.1291. Therefore, for systems noted in sub-paragraph .2 above, the phrase "excluded from these requirements" in paragraph 7 of MSC.1/Circ.1291 is not an exclusion from the general provision in SOLAS regulation 11-2/21.4.13 (remain operational in the event of fire). This exclusion pertains only to the detailed provisions in MSC.1/Circ.1291.t

30 Fuel pump arrangement required for ships (Source: MSC. 1/Circ. 1467)

to maintain normal operation of propulsion machinery when operating in emission control areas and non-restricted areas Reg. 26.3.4 30.1 For ships intending to use heavy fuel oil (HFO) or marine diesel oil (MDO) in non-restricted areas and marine fuels with a sulphur content not exceeding 0.1 per cent/m/m and minimum viscosity of 2 cSt in emission control areas, the following arrangements should be considered to be in compliance with SOLAS regulation 11-1/26.3.4:

.1 in non-restricted areas, ships provided with two fuel oil pumps that can each supply the fuel primarily used by the ship (i.e. HFO or MDO) in the required capacity for normal operation of the propulsion machinery; and

.2 in emission control areas one of the following configurations:

.1 fuel oil pumps as in .1, provided these are each suitable for marine fuels with a sulphur content not exceeding 0.1 per cent/m/m and minimum viscosity of 2 est operation at the required capacity for normal operation of propulsion machinery;

* SOLAS chapter 11-1 has been comprehensively revised and this regulation been replaced. t The unified interpretation of regulation 11-1/22-1 on the safe return to port requirement flooding detection system should only be applied to ships contracted for construction on or after 1 July 2019.

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.2 when the fuel oil pumps in .1 are suitable to operate on marine fuels with a sulphur content not exceeding 0.1 per cent/m/m and minimum viscosity of 2 cSt but one pump alone is not capable of delivering marine fuels with a sulphur content not exceeding

0.1 per cent/m/m and minimum viscosity of 2 est at the required capacity, then both pumps may operate in parallel to achieve the required capacity for normal operation of propulsion machinery. In this case, one additional (third) fuel oil pump should be provided. The additional pump should, when operating in parallel with one of the pumps in .1, be suitable for and capable of delivering marine fuels with a sulphur content not exceeding 0.1 per cent/m/m and minimum viscosity of 2 cSt at the required capacity for normal operation of the propulsion machinery; and

.3 in addition to .1, two separate fuel oil pumps should be provided, each capable of and suitable for supplying marine fuels with a sulphur content not exceeding

0.1 per cent/m/m and minimum viscosity of 2 est at the required capacity for normal operation of propulsion machinery.

Notes:

1 For the purpose of this interpretation, if a marine distillate grade fuel with a different maximum sulphur content is specified by regulation for the area of operation of the ship (e.g. EGA, specific ports or local areas, etc.) then that maximum should be applied.

2 IACS UR35.4.1 (automatic start of standby pumps) applies independent of the pump arrangement for ships holding the class notation for unattended machinery spaces.

3 Where electrical power is required for the operation of propulsion machinery, the requirements should also be applicable for machinery for power generation when such machinery is supplied by common fuel supply pumps.

31 Machinery installations - General (Source: MSC.1/Circ.1572/Rev.2)

Reg. 26.4 31.1 Dead ship condition for the purpose of regulation 11-1/26.4 should be understood to mean a condition under which the main propulsion plant, boilers and auxiliaries are not in operation and in restoring the propulsion, no stored energy for starting and operating the propulsion plant, the main source of electrical power and other essential auxiliaries is assumed to be available.

31.2 Where the emergency source of power is an emergency generator which complies with regulation 11-1/44, IACS SC185 and IACS SC124, this generator may be used for restoring operation of the main propulsion plant, boilers and auxiliaries where any power supplies necessary for engine operation are also protected to a similar level as the starting arrangements.

31.3 Where there is no emergency generator installed or an emergency generator does not comply with regulation 11-1/44, the arrangements for bringing main and auxiliary machinery into operation should be such that the initial charge of starting air or initial electrical power and any power supplies for engine operation can be developed on board ships without external aid. If for this purpose an emergency air compressor or an electric generator is required, these units should be powered by a hand-starting oil engine or a hand-operated compressor. The arrangements for bringing main and auxiliary machinery into operation should have capacity such that the starting energy and any power supplies for engine operation are available within 30 min of a dead ship condition.

32 Machinery installations - General (Source: MSC.1/Circ.1572/Rev.2)

Reg. 26.11 32.1 Arrangements complying with this regulation and acceptable "equivalent arrangements" for the most commonly utilized fuel systems are shown in appendix 1.

32.2 A service tank is a fuel oil tank which contains only fuel of a quality ready for use, i.e. fuel of a grade and quality that meets the specification required by the equipment manufacturer. A service tank should be declared as such and not be used for any other purpose.

32.3 Use of a setting tank with or without purifiers, or purifiers alone, and one service tank is not acceptable as an "equivalent arrangement" to two service tanks.

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Unified interpretations for chapter II- 1

33 Means of going astern* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 28.3 The stopping times, ship headings and distances recorded on trials, together with the results of trials to determine the ability of ships having multiple propulsion/steering arrangements to navigate and manoeuvre with one or more of these devices inoperative, should be available on board for the use of the master or designated personnel.

34 Steering gear (Source: MSC.1/Circ.1398)

Reg.29 34.1 Basic requirements

34.1.1 Two independent steering gear control systems should be provided and should be so arranged that a mechanical or electrical failure in one of them will not render the other one inoperative.

34.1.2 The term "steering gear control system" as defined in SOLAS chapter 11-1, part A, regulation 3.1, should be understood as "steering control system" covering "the equipment required to control the steering gear power actuating system".

34.2 Separation of control systems and components

34.2.1 General Wires, terminals and the components for duplicated steering gear control systems installed in units, control boxes, switchboards or bridge consoles should be separated as far as practicable. Where physical separation is not practicable, separation may be achieved by means of a fire-retardant plate.

34.2.2 Steering wheel or steering lever All electric components of the steering gear control systems should be duplicated. This does not require duplication of the steering wheel or steering lever.

34.2.3 Steering mode selector switch If a joint steering mode selector switch (uniaxial switch) is employed for both steering gear control systems, the connections for the circuits of the control systems should be divided accordingly and separated from each other by an isolating plate or by an air gap.

34.2.4 Follow-up amplifier In the case of double follow-up control (see appendix 2, example 2), the amplifiers should be designed and fed so as to be electrically and mechanically separated. In the case of non-follow-up control and follow-up control , it should be ensured that the follow-up amplifiers are protected selectively (see appendix 2, example 3).

34.2.5 Additional control systems Control circuits for additional control systems, e.g. steering lever or autopilot, should be designed for all-pole disconnection (see appendix 2, examples 1, 2 and 3).

34.2.6 Feedback units and limit switches The feedback units and limit switches, if any, for the steering gear control systems should be separated electrically and mechanically connected to the rudder stock or actuator separately.

34.2.7 Hydraulic control components

34.2.7.1 Hydraulic system components in the power actuating or hydraulic servo systems controlling the power systems of the steering gear (e.g. solenoid valves, magnetic valves) should be considered as part of the steering gear control system and should be duplicated and separated.

34.2.7.2 Hydraulic system components in the steering gear control system that are part of a power unit may be regarded as being duplicated and separated when there are two or more separate power units provided and the piping to each power unit can be isolated.

* The SOLAS requirements for steering gears have been established for ships having a traditional propulsion system and one rudder. For ships fitted with alternative propulsion and steering arrangements, such as but not limited to, azimuthing propulsors or water jet propulsion systems, SOLAS regulations 11-1/28.2, 28.3, 29.1, 29.2.1, 29.3, 29.4, 29.6.1, 29.14 and 30.2 should be interpreted as follows, except 29.14, which is limited to the steering systems having a certain steering capability due to ship speed, also in case propulsion power has failed.

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34.3 Failure detection and response of control systems

34.3.1 Failure detection

34.3.1.1 The most probable failures that may cause reduced or erroneous system performance should be detected, and should consider at least the following:

.1 power supply failure;

.2 loop failures in closed loop systems, both command and feedback loops (normally short circuit, broken connections and earth faults);

.3 if programmable electronic systems are used:

.1 data communication errors; and

.2 computer hardware and software failures; and

.4 hydraulic locking considering order given by steering wheel or lever.

34.3.1.2 All failures detected should initiate an audible and visual alarm on the navigation bridge. Hydraulic locking should always be warned individually unless system design makes manual action unnecessary.

Note: "Hydraulic locking" includes all situations where two hydraulic systems (usually identical) oppose each other in such a way that it may lead to loss of steering. It can either be caused by pressure in the two hydraulic systems working against each other or by hydraulic "by pass", meaning that the systems puncture each other and cause pressure drop on both sides or make it impossible to build up pressure.

34.3.1.3 Alternatively to 34.3.1.1.2 and 34.3.1.1.3, depending on the rudder characteristic, critical deviations between rudder order and response should be indicated visually and audibly as a steering failure alarm on the navigating bridge.

34.3.1 .4 The following parameters should be monitored:

.1 Direction: Actual rudder position follows the set value .

.2 Delay: Rudder's actual position reaches set position within acceptable time limits .

.3 Accuracy: The end actual position should correspond to the set value within the design offset tolerances.

34.3.2 System response upon failure The most probable failures , e.g. loss of power or loop failure, should result in the least critical of any new possible conditions.

35 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.1 35.1 For a ship fitted with multiple steering-propulsion units, such as, but not limited to, azimuthing propulsors or water jet propulsion systems, each of the steering-propulsion units should be provided with a main steering gear and an auxiliary steering gear or with two or more identical steering actuating systems in compliance with interpretation of SOLAS regulation 11-1/29.6.1 (see interpretation 40). The main steering gear and the auxiliary steering gear should be so arranged that the failure of one of them will not render the other one inoperative.

35.2 For a ship fitted with a single steering-propulsion unit, the requirement in SOLAS regulation 11-1/29.6.1 is considered satisfied if the steering gear is provided with two or more steering actuating systems and is in compliance with the interpretation of SOLAS regulation 11-1/29.6.1 (see interpretation 40). A detailed risk assessment should be submitted in order to demonstrate that in the case of any single failure in the steering gear, control system and power supply the ship steering is maintained.

36 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.2.1 All components used in steering arrangements for ship directional control should be of sound reliable construction to the satisfaction of the Administration or recognized organizations acting on its behalf. Special consideration should be given to the suitability of any essential component which is not duplicated. Any such essential component should, where appropriate, utilize anti-friction bearings such as ball bearings, roller bearings or sleeve bearings which should be permanently lubricated or provided with lubrication fittings.

* The SOLAS requirements for steering gears have been established for ships having a traditional propulsion system and one rudder. For ships fitted with alternative propulsion and steering arrangements, such as but not limited to, azimuthing propulsors or water jet propulsion systems, SOLAS regulations 11-1/28.2, 28.3, 29.1, 29.2.1, 29.3, 29.4, 29.6.1, 29.14 and 30.2 should be interpreted as follows, except 29.14, which is limited to the steering systems having a certain steering capability due to ship speed also in case propulsion power has failed.

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37 Steering gear (Source: MSC.1/Circ.1536)

Regs. 29.3, 37.1 In order for ships to comply with the performance requirements stated in regulations 11-1/29.3.2 and

29.4 29.4.2, they are to have steering gear capable of meeting these performance requirements when at their deepest seagoing draught.

37.2 In order to demonstrate this ability, the trials may be conducted in accordance with section 6.1.5.1 of the standard ISO 19019:2005 (Sea-going vessels and marine technology- Instructions for planning, carrying out and reporting sea trials).

37.3 On all occasions when trials are conducted with the vessel not at the deepest seagoing draught, the loading condition can be accepted on the conditions that either:

.1 the rudder is fully submerged (at zero speed waterline) and the vessel is in an acceptable trim condition .

.2 the rudder torque at the trial loading condition has been reliably predicted (based on the system pressure measurement) and extrapolated to the maximum seagoing draught condition using the following method to predict the equivalent torque and actuator pressure at the deepest seagoing draught:

where: a is the extrapolation factor. QF is the rudder stock moment (torque in the rudder stock) for the deepest service draught and maximum service speed condition. QT is the rudder stock moment (torque in the rudder stock) for the trial condition.

AF is the total immersed projected area of the movable part of the rudder in the deepest seagoing condition. AT is the total immersed projected area of the movable part of the rudder in the trial condition. VF is the contractual design speed of the vessel corresponding to the maximum continuous revolutions of the main engine at the deepest seagoing draught. VT is the measured speed of the vessel (considering current) in the trial condition.

Where the rudder actuator system pressure is shown to have a linear relationship to the rudder stock torque the above equation can be taken as:

PF = Pra

where: PF is the estimated steering actuator hydraulic pressure in the deepest seagoing draught condition. PT is the maximum measured actuator hydraulic pressure in the trial condition.

Where constant volume fixed displacement pumps are utilized then the regulations can be deemed satisfied if the estimated steering actuator hydraulic pressure at the deepest draught is less than the specified maximum working pressure of the rudder actuator. Where a variable delivery pump is utilized pump data should be supplied and interpreted to estimate the delivered flow rate corresponds to the deepest seagoing draught in order to calculate the steering time and allow it to be compared with the required time. Where AT is greater than 0.95AF there is no need for extrapolation methods to be applied .

.3 Alternatively, the designer or builder may use computational fluid dynamic (CFO) studies or experimental investigations to predict the rudder stock moment at the full seagoing draught condition and service speed. These calculations or experimental investigations should be to the satisfaction of the Administration.

37.4 In any case for the main steering gear trial, the speed of the ship corresponding to the number of maximum continuous revolutions of the main engine and maximum design pitch applies.

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38 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.3 38.1 The main steering arrangements for ship directional control should be:

.1 of adequate strength and capable of steering the ship at maximum ahead service speed which should be demonstrated;

.2 capable of changing direction of the steering-propulsion unit from one side to the other at declared steering angle limits at an average turning speed of not less than 2.3°/s with the ship running ahead at maximum ahead service speed;

.3 for all ships, operated by power; and

.4 so designed that they will not be damaged at maximum astern speed; this design requirement need not be proved by trials at maximum astern speed and declared steering angle limits.

Ship manoeuvrability tests, such as according to resolution MSC.137(76) on Standards for ship manoeuvrability, should be carried out with steering angles not exceeding the declared steering angle limits. Definition: Declared steering angle limits are the operational limits in terms of maximum steering angle, or equivalent, according to manufacturers' guidelines for safe operation, also taking into account the ship's speed or propeller torque/speed or other limitation; the "declared steering angle limits" are to be declared by the directional control system manufacturer for each ship-specific non-traditional steering mean; ship manoeuvrability tests, such as those in the Standards for ship manoeuvrability (resolution MSC.137(76)), should be carried out with steering angles not exceeding the declared steering angle limits.

39 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.4 39.1 The auxiliary steering arrangements for ship directional control should be:

.1 of adequate strength and capable of steering the ship at navigable speed and of being brought speedily into action in an emergency;

.2 capable of changing direction of the ship's directional control system from one side to the other at declared steering angle limits at an average turning speed of not less than 0.5°/s with the ship running ahead at one half of the maximum ahead service speed or 7 knots, whichever is the greater; and

.3 for all ships, operated by power where necessary to meet the requirements of SOLAS regulation 11-1/29.4.2 and in any ship having power of more than 2,500 kW propulsion power per steering-propulsion unit.

39.2 Ship manoeuvrability tests, such as according to resolution MSC.137(76), should be carried out with steering angles not exceeding the declared steering angle limits. Definition: Declared steering angle limits are the operational limits in terms of maximum steering angle, or equivalent, according to manufacturers' guidelines for safe operation, also taking into account the ship's speed or propeller torque/speed or other limitation; the "declared steering angle limits" are to be declared by the directional control system manufacturer for each ship-specific non-traditional steering mean; ship manoeuvrability tests, such as those in the Standards for ship manoeuvrability (resolution MSC.137(76)), should be carried out with steering angles not exceeding the declared steering angle limits.

40 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.6.1 40.1 For a ship fitted with a single steering-propulsion unit where the main steering gear comprises two or more identical power units and two or more identical steering actuators, an auxiliary steering gear need not be fitted provided that the steering gear:

.1 in a passenger ship, is capable of satisfying the requirements in interpretation to SOLAS regulation 11-1/29.3 (see interpretations 37 and 38) while any one of the power units is out of operation;

.2 in a cargo ship, is capable of satisfying the requirements in interpretation to SOLAS regulation 11-1/29.3 (see interpretations 37 and 38) while operating with all power units; and

* The SOLAS requirements for steering gears have been established for ships having a traditional propulsion system and one rudder. For ships fitted with alternative propulsion and steering arrangements, such as but not limited to, azimuthing propulsors or water jet propulsion systems, SOLAS regulations 11-1/28.2, 28.3, 29.1, 29.2.1, 29.3, 29.4, 29.6.1, 29.14 and 30.2 should be interpreted as follows, except 29.14, which is limited to the steering systems having a certain steering capability due to ship speed also in case propulsion power has failed.

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.3 is arranged so that after a single failure in its piping system or in one of the power units, steering capability can be maintained or speedily regained.

40.2 For a ship fitted with multiple steering-propulsion units, where each main steering system comprises two or more identical steering actuating systems, an auxiliary steering gear need not be fitted provided that each steering gear:

.1 in a passenger ship, is capable of satisfying the requirements in interpretation to SOLAS regulation 11-1/29.3 (see interpretations 37 and 38) while any one of the steering gear steering actuating systems is out of operation;

.2 in a cargo ship, is capable of satisfying the requirements in interpretation to SOLAS regulation 11-1/29.3 (see interpretations 37 and 38) while operating with all steering gear steering actuating systems;

.3 is arranged so that after a single failure in its piping or in one of the steering actuating systems, steering capability can be maintained or speedily regained; and

.4 the above capacity requirements apply regardless of whether the steering systems are arranged with common or dedicated power units. Definition: Steering gear power unit - For the purposes of alternative steering arrangements, the steering gear power unit should be considered as defined in SOLAS regulation 11-1/3. For electric steering gears, refer to SOLAS regulation 11-1/3; electric steering motors should be considered as part of the power unit and actuator.

41 Steering gear* (Source: MSC.1/Circ.1416/Rev.1)

Reg. 29.14 This interpretation is valid to steering-propulsion units having a certain proven steering capability due to ship speed, also in case propulsion power has failed. Where the propulsion power exceeds 2,500 kW per thruster unit, an alternative power supply, sufficient at least to supply the steering arrangements which complies with the requirements of SOLAS regulation 11-1/29.4.2 and also its associated control system and the steering gear response indicator, should be provided automatically, within 45 s, either from the emergency source of electrical power or from an independent source of power located in the steering gear compartment. This independent source of power should be used only for this purpose. In every ship of 10,000 gross tonnage and upwards, the alternative power supply should have a capacity for at least 30 min of continuous operation and in any other ship for at least 10 min.

42 Additional requirements for electric and (Source: MSC.1/Circ.1416/Rev.1)

electrohydraulic steering gear* Reg. 30.2 For a ship fitted with multiple steering systems, the requirements in SOLAS regulation 11-1/30.2 are to be applied to each of the steering systems.

43 Passenger ships and cargo ships (Source: MSC.1/Circ.1571)

Reg. The drainage of enclosed spaces situated on the bulkhead deck to suitable spaces below the bulkhead 35-1.2.6.1 deck is also permitted provided such drainage is arranged in accordance with the provisions of regulation 22(2) of the Protocol of 1988 relating to the International Convention on Load Lines, 1966.

44 General/Main source of electrical power (Source: MSC.1/Circ.1572/Rev.2)

and lighting systems Regs. 40, 41 44.1 Essential services and arrangements of sources of power, supply, control and monitoring to the different categories of essential services

44.1.1 Classification of essential services

44.1.1.1 Essential services are those services essential for propulsion and steering, and safety of the ship, which are made up of "Primary Essential Services" and "Secondary Essential Services". Definitions and examples of such services are given in 44.2 and 44.3 below.

44.1.1.2 Services to ensure minimum comfortable conditions of habitability are those services defined in

44.4 below.

* The SOLAS requirements for steering gears have been established for ships having a traditional propulsion system and one rudder. For ships fitted with alternative propulsion and steering arrangements, such as but not limited to, azimuthing propulsors or water jet propulsion systems, SOLAS regulations 11-1/28.2, 28.3, 29.1, 29.2.1, 29.3, 29.4, 29.6.1, 29.14 and 30.2 should be interpreted as follows, except 29.14, which is limited to the steering systems having a certain steering capability due to ship speed also in case propulsion power has failed.

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44.2 Primary Essential Services "Primary Essential Services" are those services which need to be in continuous operation to maintain propulsion and steering. Examples of equipment for "Primary Essential Services" are as follows: steering gears; pumps for controllable pitch propellers; scavenging air blower, fuel oil supply pumps, fuel valve cooling pumps, lubricating oil pumps and cooling water pumps for main and auxiliary engines and turbines necessary for propulsion; forced draught fans, feed water pumps, water circulating pumps, vacuum pumps and condensate pumps for steam plants on steam turbine ships, and also for auxiliary boilers on ships where steam is used for equipment supplying Primary Essential Services; oil burning installations for steam plants on steam turbine ships and for auxiliary boilers where steam is used for equipment supplying primary essential services; azimuth thrusters, which are the sole means for propulsion/steering with lubricating oil pumps and cooling water pumps; electrical equipment for electric propulsion plant with lubricating oil pumps and cooling water pumps; electric generators and associated power sources supplying the above equipment; hydraulic pumps supplying the above equipment; viscosity control equipment for heavy fuel oil; control , monitoring, and safety devices/systems for equipment to Primary Essential Services; fire pumps and other fire extinguishing medium pumps; navigation lights, aids and signals; internal safety communication equipment; and lighting system.

44.3 Secondary Essential Services Secondary Essential Services are those services which need not necessarily be in continuous operation to maintain propulsion and steering but which are necessary for maintaining the vessel's safety. Examples of equipment for Secondary Essential Services are as follows: windlass; fuel oil transfer pumps and fuel oil treatment equipment; lubrication oil transfer pumps and lubrication oil treatment equipment; pre-heaters for heavy fuel oil; starting air and control air compressors; bilge, ballast and heeling pumps; ventilating fans for engine and boiler rooms; services considered necessary to maintain dangerous spaces in a safe condition; fire detection and alarm system; electrical equipment for watertight closing appliances; electric generators and associated power sources supplying the above equipment; hydraulic pumps supplying the above equipment; control, monitoring, and safety systems for cargo containment systems; and control, monitoring, and safety devices/systems for equipment to Secondary Essential Services.

44.4 Services for habitability Services for habitability are those services which need to be in operation for maintaining the ship's minimum comfort conditions for the crew and passengers. Examples of equipment for maintaining conditions of habitability are as follows: cooking; heating; domestic refrigeration;

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Unified interpretations for chapter II- 1

mechanical ventilation; sanitary and fresh water; and electrical generators and associated power sources supplying the above equipment.

44.5 Regulations 11-1/40.1.1 and 11-1/41.1.1 - For the purposes of these regulations, the services as included in paragraphs 44.2 to 44.4 should be considered.

44.6 Regulation 1/-1/40.1.2-Forthe purposes of this regulation, the services as included in paragraphs44.2 and 44.3 and the services in regulations 11-1/42 or 11-1/43, as applicable, should be considered.

44.7 Regulation 1/-1/41.1.2-Forthe purposes of this regulation, the services as included in paragraphs44.2 to 44.4, except for those also listed in interpretation 45, should be considered.

44.8 Regulation 11-1/41.1.5 - For the purposes of this regulation, the services as included in paragraphs 44.2,

44.3 and 44.4 should be considered.*

44.9 Regulation 1/-1/41.5.1.2 - For the purposes of this regulation, the following interpretations are applicable:

.1 services in paragraph 44.2 should not be included in any automatic load shedding or other equivalent arrangements;

.2 services in paragraph 44.3 may be included in the automatic load shedding or other equivalent arrangement provided disconnection will not prevent services required for safety being immediately available when the power supply is restored to normal operating conditions; and

.3 services for habitability in paragraph 44.4 may be included in the load shedding or other equivalent arrangement.

45 Main source of electrical power and (Source: MSC.1/Circ.1572/Rev.2)

lighting systems Reg. 41.1.2 Those services necessary to provide normal operational conditions of propulsion and safety do not include services such as:

.1 thrusters not forming part of the main propulsion;

.2 moorings;

.3 cargo handling gear;

.4 cargo pumps; and

.5 refrigerators for air conditioning (those which are not necessary to establish a minimum condition of habitability).

46 Main source of electrical power and (Source: MSC.1/Circ.1572/Rev.2)

lighting systems Reg. 41.1.3 Generators and generator systems, having the ship's main propulsion machinery as their prime mover, may be accepted as part of the ship's main source of electrical power, provided that:

.1 they are capable of operating under all weather conditions during sailing and during manoeuvring, also when the ship is stopped, within the specified limits for the voltage variation in IEC 60092-301 and the frequency variation in IACS UR E5;

.2 their rated capacity is safeguarded during all operations given under 1, and is such that in the event of any other one of the generators failing, the services given under regulation 11-1/41.1.2 (see interpretation 45) can be maintained;

.3 the short circuit current of the generator/generator system is sufficient to trip the generator/ generator system circuit-breaker taking into account the selectivity of the protective devices for the distribution system. Protection should be arranged in order to safeguard the generator/ generator system in case of a short circuit in the main busbar. The generator/generator system should be suitable for further use after fault clearance; and

.4 standby sets are started in compliance with paragraph 2 of the interpretation of regulation 11-1/41.5.1.1 (see interpretation 47.2 below).

* See also IACS UI SC83.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter 11-1

47 Main source of electrical power (Source: MSC.1/Circ.1572/Rev.2)

and lighting systems Reg. 41.5.1.1 47.1 Where the electrical power is normally supplied by more than one generator set simultaneously in parallel operation, provision of protection, including automatic disconnection of sufficient non-essential services and, if necessary, Secondary Essential Services as defined in the unified interpretation of SOLAS regulations 11-1/40 and 11-1/41 (see interpretation 44) and those provided for habitability, should be made to ensure that, in case of loss of any of these generating sets, the remaining ones are kept in operation to permit propulsion and steering and to ensure safety.

47.2 Where Administrations permit electrical power to be normally supplied by one generator, provision should be made, upon loss of power, for automatic starting and connecting to the main switchboard of stand-by generator(s) of sufficient capacity with automatic restarting of the essential auxiliaries, in sequential operation if required. Starting and connection to the main switchboard of one generator should be as rapid as possible, preferably within 30 seconds after loss of power. Where prime movers with longer starting times are used, this starting and connection time may be exceeded upon approval from the Administration.

48 Main source of electrical power (Source: MSC.1/Circ.1572/Rev.2)

and lighting systems Reg. 41.5.1.2 48.1 The load shedding should be automatic.

48.2 The non-essential services, service for habitable conditions, may be shed and, where necessary, additionally the Secondary Essential Services, sufficient to ensure the connected generator set(s) is/are not overloaded.

49 Main source of electrical power (Source: MSC.1/Circ.1572/Rev.2)

and lighting systems Reg. 41.5.1.3 49.1 Other approved means can be achieved by:

.1 circuit breaker without tripping mechanism; or

.2 disconnecting link or switch by which busbars can be split easily and safely.

49.2 Bolted links, for example bolted busbar sections, should not be accepted.

50 Emergency source of electrical power (Source: MSC.1/Circ.1572/Rev.2)

in passenger and cargo ships Regs. 42, 43 50.1 "Blackout" as used in regulations 11-1/42.3.4 and 11-1/43.3.4 should be understood to mean a "dead ship" condition-initiating event.

50.2 "Dead ship" condition , for the purpose of regulations 11-1/42.3.4 and 11-1/43.3.4, should be understood to mean a condition under which the main propulsion plant, boilers and auxiliaries are not in operation and in restoring the propulsion, no stored energy for starting the propulsion plant, the main source of electrical power and other essential auxiliaries should be assumed available. It is assumed that means are available to start the emergency generator at all times.

50.3 Emergency generator stored starting energy is not to be directly used for starting the propulsion plant, the main source of electrical power and/or other essential auxiliaries (emergency generator excluded).

50.4 For steam ships, the 30-min time limit given in SOLAS can be interpreted as time from blackout defined above to light-off of the first boiler.

50.5 "Exceptionally" is understood to mean conditions such as:

.1 blackout situation;

.2 dead ship situation;

.3 routine use for testing;

.4 short-term parallel operation with the main source of electrical power for the purpose of load transfer; and

.5 use of the emergency generator during lay time in port for the supply of the ship's main switchboard, provided the requirements of 50.6 (Suitable measures for the exceptional use of the emergency generator for power supply of non-emergency circuits in port) are achieved and unless instructed otherwise by the Administration.

UNIFIED INTERPRETATIONS

Unified interpretations for chapter II- 1

50.6 Suitable measures for the exceptional use of the emergency generator for power supply of non-emergency circuits in port:

.1 To prevent the generator or its prime mover from becoming overloaded when used in port, arrangements should be provided to shed sufficient non-emergency loads to ensure its continued safe operation .

.2 The prime mover should be arranged with fuel oil filters and lubrication oil filters, monitoring equipment and protection devices as required for the prime mover for main power generation and for unattended operation .

.3 The fuel oil supply tank to the prime mover should be provided with a low-level alarm, arranged at a level ensuring sufficient fuel oil capacity for the emergency services for the period of time as required by SOLAS .

.4 The prime mover should be designed and built for continuous operation and should be subjected to a planned maintenance scheme ensuring that it is always available and capable of fulfilling its role in the event of an emergency at sea .

.5 Fire detectors should be installed in the location where the emergency generator set and emergency switchboard are installed .

.6 Means should be provided to readily change over to emergency operation .

.7 Control, monitoring and supply circuits for the purpose of the use of the emergency generator in port should be so arranged and protected that any electrical fault will not influence the operation of the main and emergency services .

.8 When necessary for safe operation, the emergency switchboard should be fitted with switches to isolate the circuits .

.9 Instructions should be provided on board to ensure that when the ship is under way all control devices (e.g. valves, switches) are in a correct position for the independent emergency operation of the emergency generator set and emergency switchboard.

51 Starting arrangements for emergency (Source: MSC.1/Circ.1572/Rev.2)

generating sets Reg. 44.1 Emergency generating sets should be capable of being readily started in their cold condition at a temperature of 0°C. If this is impracticable, or if lower temperatures are likely to be encountered, heating should be provided to ensure ready starting of the generating sets.

52 Starting arrangements for emergency (Source: MSC.1/Circ.1572/Rev.2)

generating sets Reg. 44.2 Each emergency generating set arranged to be automatically started should be equipped with starting devices with a stored energy capability of at least three consecutive starts. A second source of energy should be provided for an additional three starts within 30 min unless manual starting can be demonstrated to be effective.

53 Hazardous area classification (Source: MSC.1/Circ.1557/Rev.1)

Reg. 45.11 Where the prescriptive requirements within SOLAS and related Codes {IBC and IGC Codes) and the standards published by the International Electrotechnical Commission {IEC), such as, but not limited to, IEC 60092-502:1999, are not aligned, the prescriptive requirements in SOLAS and other relevant IMO instruments should take precedence and be applied. The differences between the above-mentioned documents are listed in appendix 3, as provided by IACS.

54 Protection against flooding (Source: MSC.1/Circ.1424)

Reg. 48.3 54.1 "Bilge injection system" is the same as "direct suction" referred to in SOLAS regulation 11-1/35-1.3.7.1 and 3.7.2 and is understood to mean "emergency bilge suction", which is used to discharge overboard large quantities of seawater accumulated in engine room bilges using the main circulating pump or another suitable pump as permitted by SOLAS regulation 11-1/35-1.3.7.2.

54.2 The requirements for the controls of the "valves serving a sea inlet, a discharge below the waterline or a bilge injection system" should not be applied to valves serving an emergency bilge system, provided:

.1 the emergency bilge valve is normally maintained in a closed position;

UNIFIED INTERPRETATIONS

Unified interpretations for chapter 11-1

.2 a non-return device is installed in the emergency bilge piping; and Note: A normally closed non-return valve with positive means of closing is considered to satisfy both .1 and .2 above .

.3 the emergency bilge suction piping is located inboard of a shell valve that is fitted with the control arrangements required by SOLAS regulation 11-1/48.3.

UNIFIED INTERPRETATIONS

Appendices to unified interpretations for chapter 11-1

Appendix 1 (Source: MSC.1/Circ.1572/Rev.2) Examples of application for the most common systems

1 Example 1

1.1 Requirement according to SOLAS - Main and auxiliary engines and boiler(s) operating with heavy fuel oil (HFO) (one fuel ship)

HFO Serv. TK HFO Serv. TK MOOTK Capacity for at least 8 h Capacity for at least 8 h For initial cold starting Main Eng.+ Main Eng.+ or repair work Aux. Eng.+ Aux. Eng.+ Engines/Boiler Aux. Boiler Aux. Boiler

1.2 Equivalent arrangement HFO Serv. TK MOO Serv. TK Capacity for at least 8 h Capacity for at least 8 h Main Eng.+ Main Eng.+ Aux. Eng. + Aux. Eng.+ Aux. Boiler Aux. Boiler This interpretation only applies where main and auxiliary engines can operate with HFO under all load conditions and, in the case of main eng ines, during manoeuvring.

For pilot burners of auxiliary boilers if provided, an additional marine diesel oil (MOO) tank for 8 hours may be necessary.

2 Example 2

2.1 Requirement according to SOLAS - Main engine(s) and auxiliary boiler(s) operating with HFO and auxiliary engine operating with MOO HFO Serv. TK HFO Serv. TK MOO Serv. TK MOO Serv. TK Capacity for at least 8 h Capacity for at least 8 h Capacity for at Capacity for at Main Eng.+ Main Eng.+ least 8 h least 8 h Aux. Boiler Aux. Boiler Aux. Eng. Aux. Eng.

2.2 Equivalent arrangement MOO Serv. TK MOO Serv. TK Capacity for at least the Capacity for at least the HFO Serv. TK highest of: highest of: Capacity for at least 8 h • 4 h Main Eng. + Aux. Eng. • 4 h Main Eng. + Aux. Eng. Main Eng.+ + Aux. Boiler + Aux. Boiler Aux. Boiler or or • 8 h Aux. Eng. + Aux Boiler • 8 h Aux. Eng. + Aux Boiler The arrangements in paragraphs 1.2 and 2.2 apply, provided the propulsion and vital systems which use two types of fuel support rapid fuel changeover and are capable of operating in all normal operating conditions at sea with both types of fuel (MOO and HFO).

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0 Appendix 3 (Source: MSC.1/Circ.1557/Rev.1)

r- ► Summary of discrepancies on the hazardous area classification issues flJ ("') among the SOLAS Convention, the IBC and IGC Codes and standard IEC 60092-502:1999 0 zVl No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes 0 C

0 1 Hazardous area and Within 5 m Within 4.5 m radius; Per UI SC70 and ~ m classification on open radius; SOLAS IEC 60092-502:1999, MSC.1/Circ.1120: deck from the cargo regulation 11-2/11.6.2.2. 4.2.2.7 and 4.2.3.1. Areas on open deck, or

0 tank ventilation outlet m Reference is made to Zone 1: open areas semi-enclosed spaces

0 for small flow by thermal UI SC70. on deck within a 3 m on open deck, within =i variations radius. 3 m of cargo tank

6 Zone 2: additional 1.5 m ventilation outlets which z permit the flow of small N beyond Zone 1; volumes of vapour or 8 .i:.. IEC 60092-502:1999, gas mixtures caused

4.2.2.7 and 4.2.3.1.

by thermal variation are defined as Zone 1. Areas within 2 m beyond the zone specified above are to be considered Zone 2. ~ - -- - )> "'O "'O ro :J Cl.. ri' ro ,.,, 0 C :J =..; ni' Cl.. 5· ,...,. ro … "'O … ro ,...,. p., ,...,. i5' ,.,, :J

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2 The separation distance At least 10 m; the At least 10 m; IBC Code, At least 10 m; IGC Code, At least 6 m; For oil tankers, 9-:

of the nearest air intakes openings shall paragraph 8.3.4.2. paragraph 8.2.11.2. IEC 60092-502:1999, and chemical and @ for non-hazardous be arranged in At least 15 m; IBC Code, Cargo tank PRV vent 4.2.2.7, 4.2.3.1 and gas carriers, the spaces from the tank accordance with SOLAS 8.2.5. requirements of SOLAS, 0 paragraph 15.12.1.3 exits: at least equal to § ventilation outlet for regulation 11-2/4.5.3.4.1 (although toxicity not B or 25 m, whichever is IBC Code and IGC small flow by thermal referred to in SOLAS flammability). less. Code are to be met, as ~ variations. regulation 11-2/11.6.2. applicable. Q. For ships less than 5·

90 m in length, smaller ro distances may be -a permitted; IGC Code, ri3 ~ paragraph 8.2.11.1. g. ::i Hazardous zone in way SOLAS 10 m from a cargo For tankers, a minimum of P/V breaker regulation 11-2/11.6.2.2: gas outlet intended distance of 10 m "'o' … at least 10 m. for the passage of applies. g_ large volumes of gas or vapour mixture ~ during cargo loading; ro … IEC 60092-502:1999, =;:::

4.2.2.8 and 4.2.3.2 based on UI SC140, otherwise 4.5 m from a P/V breaker which does not release large volumes of gas or vapour locally; IEC 60092-502:1999, 4.2.2.7 tl'l and 4.2.3.1. 0 r- ► tl'l 8z Vl 0 r 0 ~ m 0 m 0 =l B z N 0 N .j:::..

0 No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes r- ► flJ At least 10 m; IBC Code, At least 10 m; IGC Code, At least 11.5 m;

3 The separation distance At least 10 m; For oil tankers, ("') of the nearest air intakes SOLAS regulation paragraph 12.1.5. paragraph 12.1.6. IEC 60092-502:1999, and chemical and

0 for non-hazardous 11-2/4.5.3.4.1.3. At zVl At least 15 m; IBC Code, Cargo tank PRV vent 4.2.2.8, 4.2.3.2 and gas carriers, the spaces from the tank least 10 m; SOLAS paragraph 15.12.1. exits: at least equal to 8.2.5. requirements of SOLAS,

0 vent outlets for cargo regulation 11-2/11.6.2.2 IBC Code and IGC C 3 (although toxicity not B or 25 m, whichever is

0 loading, discharging and referring back to SOLAS less. Code are to be met, as flammability). ~ m ballasting regulation 11-2/4.5.3.4.1. For ships less than applicable.

0 90 m in length, smaller Any other requirement m distances may be on the location of air

0 permitted; intakes and openings =i such as in SOLAS

6 IGC Code, regulation 11-2/4.5.2, z paragraph 8.2.11 .1. IBC Code 3.2, N All other vent outlets IGC Code 3.2 is to be 8 .i:.. connected to the cargo also complied with. containment system: at least 10 m; IGC Code, paragraph 8.2.11.2.

4 The separation distance MSC.1/Circ.1321, At least 10 m; IBC Code, At least 10 m; IGC Code, At least 6 m; For oil tankers, the of the nearest air intakes part IV, chapter 3, paragraph 12.1.5. paragraph 12.1.6. IEC 60092-502:1999, minimum distance of for non-hazardous areas paragraph 1.2: the Ventilation ducts, air 4.2.2.7, 4.2.3.1 and MSC.1/Circ.1321 to be from the ventilation position of the cargo intakes and exhaust 8.2.5. met. exhaust outlet for pump-room vent outlet outlets serving artificial For chemical tankers, )> hazardous areas should be arranged ""O ventilation systems IBC Code 12.1.5 applies. ""O ro (i.e. cargo compressor at a distance of at shall be positioned :J room, cargo pump- least 3 m measured For gas carriers, the Cl.. in accordance with minimum distance of ri" room, etc.) horizontally from any recognized standards;t ro ,.,, ignition source and from 6 m per IEC standard IGC Code, 60092-502:1999 applies. 0 the nearest opening to paragraph 12.1.5. C accommodation, service :J =..; or machinery spaces. ni" Cl.. :J ro ""' ""O ~ i5" ,.,, :J 0 ""' ("") :::r Ill _. ffi: O"I _. I w t IEC60092-502:1999

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         5     Hazardous area and                                  Within the coaming        Within 3 m beyond the     Within 4.5 m radius;        For bow and stern      9-:
               classification on open                              required by 3.7.7 or      spillage coming up to a   IEC 60092-502:1999,         loading/unloading      @
               deck from the cargo                                 within a 3 m radius       height of 2.4 m above     4.2.2.10 and 4.2.3.1.       arrangements on oil
               shore connection or                                 beyond the coaming;       the deck; IGC Code,                                   tankers reference is   0
                                                                                                                       Zone 1: open areas                                 §
               spillage coaming                                    IBC Code,                 paragraph 1.2.24.15.      on deck within a 3 m        made to IACS UR F16.
                                                                   paragraph 3.7.8.                                    radius, up to a height of                          ~
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                                                                   It should be noted that                             2.4 m above the deck.                              5·
                                                                   paragraph 3.7.8 only                                Zone 2: additional 1.5 m                           ro
                                                                   applies to stern or bow                             beyond Zone 1;                                     -a
                                                                   loading arrangements.                               IEC 60092-502:1999,                                ri3
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         6     Opening to main           Subject to                IBC Code,                                           The intent of a minimum
               cargo control stations    Administration;           paragraph 3.2.3.                                    distance of 1.5 m from
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               and service spaces        SOLAS regulation                                                              the boundaries of any                              g_
               not giving access to      11-2/4.5.2.2.                                                                 hazardous area is to be
               accommodations,                                                                                         followed;                                          ~
               control stations
                                         Note: SOLAS
                                                                                                                       IEC 60092-502:1999,                                ro....
                                         regulation 11-2/4.5.2.2
               and similar spaces                                                                                      8.2.5.                                             =;:::
                                         does not categorize the
               containing sources of     space as hazardous or
               ignition                  non-hazardous.
          7    Openings to               Not less than 4% of       Not less than 4% of       Not less than 4% of       At least 1.5 m from
               accommodation spaces,     L, but not less than      L, but not less than      L, but not less than      the boundaries of any
               service spaces, control   3 m from the end of       3 m from the end of       3 m from the end of       hazardous area;
               stations and machinery    the superstructure        the superstructure        the superstructure or     IEC 60092-502:1999,
               spaces facing the cargo   or deckhouse. (This       or deckhouse. (This       deckhouse.                8.2.5.
tl'l           area                      distance need not         distance need not         (This distance need not
0                                        exceed 5 m); SOLAS        exceed 5 m); IBC Code,
r-                                                                                           exceed 5 m); IGC Code,
►                                        regulation 11-2/4.5.2.    paragraph 3.2.3.          paragraph 3.2.4.1.
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8 Access doors to Access doors to Access doors to Access doors to The forecastle spaces ("') forecastle spaces forecastle spaces forecastle spaces forecastle spaces installed the access 0 zVl containing source of containing source of containing source of containing source of doors facing the cargo ignition facing the cargo ignition shall not face ignition shall not face ignition shall not face area shall be designated

0 area the cargo area; the cargo area; the cargo area; as the hazardous area of

0 SOLAS regulation IBC Code, IGC Code, Zone 2;

~ m 11-2/4.5.2.1. paragraph 3.2.3. paragraph 3.2.4.1. IEC 60092-502:1999,

0 Access doors to Reference is made to Accesses to forecastle 4.2.

m forecastle spaces UI SC120. spaces containing See also

0 containing source of sources of ignition may IEC 60092-502:1999, =i ignition shall not face be permitted through a 4.2.3.6 as commented in

6 the cargo area and are single door facing the item 18 below.

z to be at not less than cargo area, provided N

8 3 m from the end of the doors are located .i:.. the superstructure or outside hazardous areas deckhouse. as defined in chapter 10; (This distance need not IGC Code, exceed 5 m); SOLAS paragraph 3.2.4.4. regulation 11-2/4.5.2.1. Reference is made to Reference is made UI SC120. to UI SC120.

9 Ventilation of cargo 20 air changes/hour; 30 air changes/hour; 30 air changes/hour; Spaces containing For oil tankers, SOLAS )>

pump-rooms (cargo SOLAS IBC Code, IGC Code, sources of release: regulation 11-2/4.5.4.1 -0 -0 handling spaces on regulation 11-2/4.5.4.1 paragraph 12.1.3. paragraph 12.1.3. 30 air changes/hour; applies. (Reference is ro :J chemical and gas and MSC.1/Circ.1321, 45 air changes/hour; IEC 60092-502:1999, also made to IACS UR Cl.. ri' carriers) part IV, chapter 3, IBC Code, 8.1.3. F21.) ro ,.,, paragraph 1.1. paragraph 15.17 (toxic). For chemical tankers, Note: The IEC standard 0 refers to spaces the IBC Code C :J "containing sources of requirements apply. =..; ni' release", while the IBC For gas carriers, the Cl.. and IGC Codes refer IGC Code requirements :J to spaces for "cargo apply. ro handling operations". ""' -0 Note: The IEC standard refers to spaces "containing sources of ~ i5' release", while the IBC ,.,, :J

and IGC Codes refer 0 to spaces for "cargo ""' (')

handling operations". :::r Ill

… Further, IEC does not consider the threat of ffi: O"I IJ7 toxicity … I

_. ).. °'°' No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes :g (1) ::i

10 Ventilation of hazardous 20 air changes/hour; Spaces not containing The IBC Code 9-:

spaces not containing spaces normally entered sources of release: 6 air categorization differs @ source of release IBC Code, changes/hour; from that of IEC (spaces paragraph 12.2. IEC 60092-502:1999, not normally entered 0 8.1.3. not containing cargo §

8 air changes/hour;

spaces not normally handling equipment vs ~ entered; IBC Code, spaces not containing Q. sources of release). 5· paragraph 12.3 ro (16 air changes/hour if -a portable). ri3 ~

11 Concentration of gas 10% LFL (lower 10% LFL for cargo Alarms shall be 30% LFL; IEC 60092- IEC 60092-502:1999, g.

implying that space is flammable limit) for pump-room; IBC Code, activated for flammable 502:1999, 8.4.2. 8.4.2 applies to spaces ::i non-hazardous (alarm cargo pump-rooms paragraph 11.1.1.7 products when the Note: The requirement protected by over- "'o' limits) in tankers; SOLAS (resolution vapour concentration pressure. This is not … of the standard applies g_ regulation 11-2/4.5.10.1.3. MSC. 219(82)), reaches 30% of the to spaces protected by considered equivalent to 30% LFL for all ballast clarifying that SOLAS lower flammable limit, over-pressure. a cargo pump-room. ~ tanks and void spaces regulation 11-2/4.5.10 for the spaces of ro … of double-hull and applies, in which paragraph 13.6.2 of the =;::: double-bottom spaces case "hydrocarbon IGC Code; IGC Code, adjacent to the cargo gases" are replaced by paragraph 13.6.15. tanks in oil tankers "flammable vapours". of 20,000 tonnes deadweight and above; SOLAS regulation 11-2/4.5.7.3 and the FSS Code, chapter 16, tl'l paragraph 2.2.3.3. 0 r- 12 Fan monitoring (air lock) Where spaces Motor running or Monitoring of current or ► tl'l are protected by rotating fan monitoring power supply is not as pressurization, the device is not accepted; reliable as a differential 8z ventilation shall be IEC 60092-502:1999, pressure or flow Vl designed and installed 8.4.3. monitoring device. 0 r in accordance with recognized standards; *

0 IGC Code, ~ m paragraph 3.6.2. 0 m 0 =l B z N 0 N .j:::.. * IEC 60092-502:1999. As per the Note to 8.4.3 of the standard, a fan motor or a fan rotation monitoring device will not satisfy this requirement.

0 No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes r- ► flJ When carrying cargoes IEC 60092-502:1999,

13 Tanks for heated cargo Tanker requirements Follows SOLAS principle ("') apply to tankers related to flashpoint. heated to temperature 4.3.2 and the IBC Code, 0 zVl carrying cargo with However, the IBC within 15°C of their flash paragraph 10.1.6 are in a flashpoint (FP) Code considers point, hazardous zone agreement.

0 below 60°C; SOLAS classification for tankers C non-flammable products SOLAS cites do not

0 regulation 11-2/1.6.1. and products with a carrying cargoes with specifically address ~ m For petroleum cargoes flashpoint of 60°C and FP not exceeding 60°C applies; IEC 60092- heated cargo.

0 with FP of 60°C and above in a different way above only deck (paragraphs 11.1. 2 and 502:1999, 4.3.2 m

0 foam requirements 11.1.3); in the case of a referring back to 4.2.

=i apply; SOLAS heated cargo, carriage

6 regulation 11-2/1.6.4. conditions might need z Hazardous zone to be established N classification and and the requirements 8 .i:.. electrical installation for cargoes having a shall be complied with; flashpoint not exceeding IEC 60092-502:1999; 60°C applied; IBC Code, SOLAS paragraph 10.1.6. regulation 11-1/45.11. ~ … ,; r ~-

14 Classification of cargo Hazardous zone IGC Code, IEC 60092-502:1999, If hazardous area pump-room classification and paragraph 1.3.17.7; 4.1.4.1 table 1 and classification is electrical installation IGC Code, 4.2.2.4 may indicate dependent on shall be complied with; paragraph 1.2.24.6. that cargo pump-rooms ventilation, then )> -0 IEC 60092- 502:1999; are Zone 1. However, ventilation is not -0 ro SOLAS as ventilation is expected to be :J Cl.. regulation 11-1/45.11. only running during discontinued. ri' cargo handling, the ro ,.,, requirements may 0 be interpreted that C :J it is Zone O (flag =..; Administration position ni' Cl.. may be required). :J ro ""' -0 ~ i5' ,.,, :J 0 ""' (') :::r Ill ffi: °' '-I __. I _. ).. °'co No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes :g (1) ::i

15 Discontinuation of Spare parts shall be Where fans are required, IEC 60092-502:1999, 9-:

ventilation for long carried for each type of full required ventilation 8.3.1 includes an @ periods ventilation fan required capacity for each space assumption that on board; IBC Code, shall be available after ventilation shall not be 0 paragraph 12.1.9. failure of any single fan, discontinued for long § or spare parts shall be periods. ~ provided comprising Q. a motor, starter 5· spares and complete ro rotating element, -a ri3 including bearings of ~ each type; IGC Code, g.

16 Gas carrier ballast tanks ., - ✓ paragraph 12.1.8 . Ballast tanks may be Ballast tanks on gas ::i "'o' … connected to pumps in carriers, separated g_ machinery spaces; from a hold space, IGC Code, where cargo is carried ~ ro … paragraph 3.7.5. in a cargo tank requiring a secondary =;::: barrier, by a single gastight boundary, are hazardous areas Zone 1. -..-, ... ---...-...= ---- •• ''" •r ,-

17 Gas carrier hold space Hold spaces of gas carriers (except those with type C tanks), where a secondary tl'l barrier is required, are 0 r- considered hazardous ► areas Zone O; tl'l IEC 60092-502:1999, 8z 18 Access to forward Access openings to Reference is made to Reference is made to

4.4.1 and annex D.

It is implied that as 1. SOLAS regulations Vl

0 spaces below level of service spaces, control UI SC120. UI SC120. long as the sill height is 11-2/4.5.2.1 and 4.5.2.2, r main deck stations and machinery above 0.5 m then it is etc. restrict the

0 spaces are not to face exempted from SOLAS installation of openings ~ m the cargo area; SOLAS and can face the cargo (e.g. doors) facing cargo regulation 11-2/4.5.2. area; areas. 0 m Reference is made to IEC 60092-502:1999, 2. IEC60092-502:1999

0 UI SC120. 4.2.3.6. 4.2.3.6 addresses =l classification of B hazardous areas. z N 0 N .j:::..

0 No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes r- ► flJ

19 Hazardous zone The entire deck area up IACS considers that ("') classification on main to 2.4 m is considered a more reasonable 0 zVl deck of tankers with as Zone 1 if structures criterion might be that deck girders are provided as they are the zone from deck

0 considered to restrict level up to the top of

0 natural ventilation; the structures should ~ m IEC 60092-502:1999, 4.2.2.11. be Zone 1 and the remaining zone up

0 to 2.4 m should be

0 considered Zone 2.

=i 20 Location of fan motors To be located outside To be located outside IEC 60092-502:1999;

6 for cargo pump-room ducts; IBC Code, ducts; IGC Code, follows zone z and compressor room paragraph 12.1.8. paragraph 12.1.7. classification. i.e. if N Zone 0, outside 8 .i:.. ventilation duct (based on 6.5.2). If Zone 1, inside OK, provided certified for Zone 1.

)> ""O ""O ro :J Cl.. ri" ro ,.,, 0 C :J =..; ni" Cl.. 5· ro ""' ""O nl -s:;- o· ,.,, :J

0 ""' ("") :::r Ill ""O ro $I I~

_. ).. '.J 0 No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes :g (1) ::i

21 Openings to Shall not face the cargo Shall not face the Shall not face the Access doors or other 9-:

accommodation spaces, area. Can be located at cargo area. They shall cargo area. They shall openings shall not @ service spaces, control the transverse bulkhead be located on the end be located on the end be provided between stations and machinery not facing the cargo bulkhead not facing the bulkhead not facing the an area intended 0 spaces facing the cargo area, at a distance of at cargo area and/or on cargo area or on the to be considered § area least 4% of the length the outboard side of the outboard side of the as non-hazardous of the ship but not less superstructure or deck- superstructure or deck- and a hazardous ~ Q. than 3 m from the end house at a distance of at house or on both at a area, or between a 5· of the superstructure least 4% of the length (L) distance of at least 4% space intended to be ro or deckhouse facing the cargo area. This of the ship but not less than 3 m from the end of the length (L) of the ship but not less than considered as Zone

2 and a Zone 1 space -a ri3 distance need not of the superstructure or 3 m from the end of except where required ~ exceed 5 m; SOLAS deckhouse facing the the superstructure for operational reasons. g. regulation 11-2/4.5.2.1. cargo area. or deckhouse facing Where access doors ::i Refer to SOLAS the cargo area. This or other openings are "'o' This distance, however, distance, however, need provided for operational … regulation II- 2/4.5.2.2 need not exceed g_ for permitted access not exceed 5 m. Refer reasons, 4.1.5.2, 4.1.5.3,

5 m. Refer to same to same paragraph for 4.1.5.4 or 4.1.5.5 apply; ~ doors to main cargo control stations and paragraph for permitted wheelhouse doors and IEC 60092-502:1999, ro … access doors to spaces windows; IGC Code, 4.1.5. service spaces and to not having access to =;::: wheelhouse doors and paragraph 3.2.4. Where a space has an accommodation and windows. service spaces and opening into an adjacent, control stations, and more hazardous space wheelhouse doors and or area, it may be made windows; IBC Code, into a less hazardous paragraph 3.2.3. space or non-hazardous space by pressurization designed and operated in accordance with the tl'l requirements given 0 r- in 8.2 and 8.4; ► IEC 60092-502:1999, tl'l 8.1.4. 8z Note: SOLAS and Codes refer to permitted Vl openings of spaces, 0 r while the IEC standard

0 defines hazardous areas.

_, … ,_., .. ~ m 0 m 0 =l B z N 0 N .j:::..

0 No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes r- ► flJ IEC 60092-502:1999,

22 Air locks IGC Code, The IGC Code is more ("') paragraph 3.6. 4.1.5.3. specific for air locks 0 zVl installed between the hazardous area on the

0 open weather deck and

0 non-hazardous spaces, ~ m also attention is to be paid to the audible and

0 visual alarm on both

0 sides of air lock.

,.,. =i 23 Earthed distribution Earthed distribution Distribution systems:

6 systems and hull return systems shall not Distribution systems z systems be used in a tanker. shall comply with the N The Administration provisions of 8 .i:.. may exceptionally IEC 60092-201:2019. permit in a tanker the Both insulated and earthing of the neutral earthed distribution for alternating current systems are permitted; power networks of systems with a hull or 3,000 V (line to line) structure return, other and over, provided that than those noted under any possible resulting 5.2.2, are not permitted; current does not flow IEC 60092-502:1999, )> directly through any 5.2.1. -0 of the dangerous -0 ro spaces; SOLAS The following systems :J Cl.. regulation 11-1/45.4.1. are permitted to be of ri' hull or structure return ro ,.,, The hull return system type: of distribution shall not 0 be used for any purpose - limited and locally C :J earthed systems =..; in a tanker; SOLAS ni' regulation 11-1/45.3.1. outside any hazardous Cl.. area; :J The above regulation does not preclude under - intrinsically-safe ro ""' -0 conditions approved by systems; the Administration the use of: - impressed current ~ i5' cathodic protective systems; ,.,, :J - impressed current cathodic protective 0 IEC 60092-502:1999, ""' (') systems; 5.2.2. :::r Ill _. ffi: _. '.J _. I _. ).. '.J N No. Title SOLAS IBC IGC IEC 60092-502:1999 Explanatory Notes :g (1) ::i - limited and locally The neutral and any 9-: earthed systems; or conductor required @ - insulation level for protection against electric shock shall not 0 monitoring devices § provided the be connected together circulation current or combined in a ~ does not exceed single conductor in a Q. hazardous area; 5·

30 mA under the ro IEC 60092-502:1999, most unfavourable 5.2.3. -a conditions. ri3 ~ SOLAS g. regulation 11-1/45.3.2. ::i

24 Hazardous zone Hazardous zone IBC Code, chapter 10: IGC Code, The cargo tanks, "'o' IEC 60092-502:1999. paragraph 1.2.24.9 … classification on main classification and including all ballast tanks g_ deck of tankers electrical installation with cargo tank area; shall be complied with; IEC 60092-502:1999, ~ IEC 60092-502:1999; 4.2.2.11 and 4.2.3.5 ro … SOLAS (areas on open deck over =;::: regulation 11-1/45.11. cargo tanks as per the above IEC paragraphs do not coincide with the definition of the cargo area in SOLAS or the Codes).

tl'l 0 r- ► tl'l

8z Vl 0 r 0 ~ m 0 m 0 =l B z N 0 N .j:::..

Construction - Fire protection, fire detection and fire extinction

Construction - Fire protection, fire detection and fire extinction

Part A General

Regulation 1 Application

Regulation 2 Fire safety objectives and functional requirements

Regulation 3 Definitions

Part B Prevention of fire and explosion

Regulation 4 Probability of ignition

Regulation 5 Fire growth potential

Regulation 6 Smoke generation potential and toxicity

Part C Suppression of fire

Regulation 7 Detection and alarm

Regulation 8 Control of smoke spread

Regulation 9 Containment of fire

Regulation 10 Fire fighting

Regulation 11 Structural integrity

Part D Escape

Regulation 12 Notification of crew and passengers

Regulation 13 Means of escape

Part E Operational requirements

Regulation 14 Operational readiness and maintenance

Regulation 15 Instructions, on-board training and drills

Regulation 16 Operations

Part F Alternative design and arrangements

Regulation 17 Alternative design and arrangements … 266

Part G Special requirements

Regulation 18 Helicopter facilities

Regulation 19 Carriage of dangerous goods

Regulation 20 Protection of vehicle, special category and ro-ro spaces