Section 1 General requirements

1.1.1 The requirements of this Chapter are additional to those of Pt 5, Ch 11 Ship Piping Systems and are applicable to ships which are intended for the carriage of liquids in bulk, being self-propelled with machinery aft or non-propelled (barges) being towed, pushed or carried alongside another ship.

1.1.2 For the classification of dangerous liquids into Classes 2, 3, 6.1, 8 and 9, see Pt 4, Ch 6, 1.3 Structural configuration.

1.1.3 For the significance of tankers Types G, C and N and cargoes that may be carried, see Pt 4, Ch 6, 1.4 Class notation & Pt 4, Ch 6, 1.5 List of Defined Cargoes.

1.1.4 For applications and definitions, see Pt 4, Ch 6, 1 General

1.1.5 The requirements of this Chapter basically take into account the European provisions concerning the International Carriage of Dangerous Goods by Inland Waterways ADN which assume heavy traffic on relatively narrow waterways through heavily populated areas. ADN is an abbreviation from Accord européen relative au transport international des merchandises Dangereuses par voie de Navigation intérieure. See also Pt 4, Ch 4, 1.2 International Regulations.

1.1.6 Although the contents of this Chapter take the ADN Regulations into account, the issue of an ADN Certificate on behalf of the Relevant Authorities requires full compliance with their Regulations.

1.1.7 In addition to the requirements of this Chapter, attention is to be given to any National and International technical and operational requirements of countries where the ship is registered or operating, and which are outside the area of ADN legislation or classification as defined in these Rules.

1.1.8 In addition to the requirements of this Chapter the Rules and Regulations for the Construction and Classification of Ships for the Carriage of Liquefied Gases in Bulk, July 2022 (hereinafter referred to as the Rules for Ships for Liquefied Gases) are to complied with for Type G tankers as far as they are applicable.

1.2.1 In addition to the plans and particulars required in Pt 5, Ch 11 Ship Piping Systems, the following plans (in diagrammatic form) are to be submitted for consideration:

1. Pumping arrangements at the fore and aft ends, and drainage of cofferdams and pump-rooms.

2. General arrangements of cargo piping in tanks and on deck.

3. For Type G tankers the maximum vapour pressure and minimum liquid temperature.

4. General arrangements of cargo tank vents. The plan is to indicate the type and position of the vent outlets and distance from any superstructure, erection, air intake, etc.

5. Arrangements of inert gas piping systems, together with full details of inert gas plant, if fitted. See Pt 5, Ch 13, 9 Inert gas systems.

6. Details of alarms and safety arrangements required by Pt 5, Ch 13, 1.6 Cargo pump-room. See also Pt 6, Ch 1, 2 Essential features for control, alarm and safety systems.

7. Pressure drop calculations, see Pt 5, Ch 13, 5.5 Loading and unloading rates for Type C and Type N-closed tankers.

8. Cargo heating systems, see Pt 5, Ch 13, 7 Cargo heating arrangements.

9. Water spray systems, see Pt 5, Ch 13, 8.2 Water spray system.

1.3.1 All materials used in the cargo pumping and piping systems and any other piping systems which may come into contact with the cargo are to be suitable for use with the intended cargoes.

1.3.2 Materials for cargo piping systems are to comply with the requirements of Pt 5, Ch 10 Piping Design Requirements as follows:

Class I or II systems for Type G Tankers depending on the service. See also Pt 5, Ch 10, 9.3 Classes of pipe.

Class II systems for Type C Tankers.

Class II for Type N Tankers carrying toxic or corrosive media.

Class III for all other Type N Tankers.

1.3.3 For cargoes which are highly corrosive, materials may be subject to a special consideration.

1.3.4 Where stainless steel is required or accepted as an alternative to mild steel, it is to be essentially an austenitic or duplex type and comply with the appropriate requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022. Alternative austenitic or duplex grades of stainless steel may be accepted provided they comply with National or Proprietary specifications and are suitable for the intended purpose.

1.3.5 For materials used on board Type G tankers carrying LPG, reference is made to Pt 5, Ch 10, 9.4 Materials for additional requirements.

1.3.6 Wood, aluminium alloy or plastic materials within the cargo area are in general not acceptable. However, consideration will be given to special cases or to arrangements which are equivalent to those required by these Rules.

1.3.7 Vapour collecting or Vapour return pipe lines are to be suitably protected against corrosion.

1.3.8 A list of Defined Cargoes, intended to be carried on board, is to be established. Due account is to be given to the materials proposed. See Pt 4, Ch 4, 1.3 Dangerous liquids. See Pt 4, Ch 5, 1.5 List of Defined Cargoes for Type G tankers and Pt 4, Ch 6, 1.5 List of Defined Cargoes for Type C and N tankers.

1.3.9 For a list of dangerous goods, see the ADN, Table C, Part 3. Subject list of chemicals could be downloaded from: http://www.ccr-zkr.org. See also Pt 4, Ch 6, 1.3 Structural configuration.

1.3.10 All additional requirements for the particular substance as contained in Table C of Part 3 of the ADN are to be complied with by the particular tanker before a substance is allowed to be carried. This also includes any additional requirements contained in column 20 of Table C.

1.4.1 All piping, valves and fittings are to be suitable for the maximum pressure to which the system can be subjected.

1.4.2 Piping subjected to pressure is to be of seamless or other approved type, and is to comply with the requirements of Chapter 10. Alternatively, longitudinally welded pipes could be accepted, provided the method of welding is acceptable and the weld will be Non-Destructive Examined in compliance with Pt 5, Ch 14, 6 Non-Destructive Examination.

1.4.3 Joints in cargo piping, outside the cargo tanks, are preferably to be of welded construction. Where used, the number of flanged joints is to be kept to a minimum and the types of flange attachments are to be in accordance with Pt 5, Ch 10, 2 Carbon and low alloy steels.

1.4.4 For Type C & N tankers, threaded pipe joints/ connections of an approved type are acceptable for NB 25 and smaller. A maximum diameter of 51 mm could be accepted for cargo oil only. See also Pt 5, Ch 10, 2.10 Screwed fittings.

1.4.5 For Type G tankers, screwed couplings could be accepted only for accessory lines and instrumentation lines with external diameters of 25 mm or less, provided the couplings are of an approved type.

1.4.6 Loading and discharge pipes, including stripping pipes are to be permanent pipes.

1.5.1 For definition of cargo zone, see Pt 4, Ch 4, 1.1 Application and definitions.

1.5.2 Internal combustion engines, or any other equipment which could constitute a possible source of ignition, are not to be situated within the cargo zone, except in the case of Type N-open tankers not built in compliance with ADN requirements.

1.5.3 Any air intakes for machinery spaces and engines are to be so arranged that their openings are not less than 2 m outside the cargo zone.

1.5.4 For the requirements for earthing and bonding of pipework for the control of static electricity, see Pt 6, Ch 2 Electrical Installations.

1.5.5 Outlets of exhaust gas lines from engines are to be provided with a device to prevent the discharge of sparks such as spark arrestors. For all tankers, exhaust lines from engines are not to be led through the cargo zone, the distance between their outlets and the cargo zone shall be not less than 2 m and the exhaust gases should be blown out in a direction away from the ship.

1.5.6 For protection against the ingress of gases within accommodations and entrances ( i.e. the relevant distances from openings and equipment in the cargo zone and openings and equipment outside the cargo zone) see Pt 4, Ch 6, 3.3 Shell plating.

1.6.1 Cargo pump-rooms, if fitted, are to be totally enclosed and have no direct communication with machinery spaces. For bilge drainage arrangements in pump-rooms, see Pt 5, Ch 13, 2.2 Drainage and/or ballasting of spaces within the cargo zone.

1.6.2 For ships required to comply with the ADN Regulations, the cargo pump room is to be separated from the engine room or service space outside the cargo zone by a cofferdam, hold space containing cargo tanks or service space. Alternatively, the bulkhead between the machinery space/pump room or service space outside the cargo zone/pump room is to be provided with a fire insulation A-60 in accordance with Regulation 3 - Definitions. This requirement is not applicable for Type N - open tankers. Shaft penetrations for pumps as per Pt 5, Ch 13, 2.2 Drainage and/or ballasting of spaces within the cargo zone 2.2.12 and Pt 5, Ch 13, 3.2 Cargo pumps and compressors 3.2.5 are not acceptable for bulkheads having an A-60 insulation.

1.6.3 Pump-rooms are to be situated within the cargo zone and are to be provided with ready means of access from the deck.

1.6.4 Alarms and safety arrangements are to be provided as indicated in Pt 5, Ch 13, 1.6 Cargo pump-room 1.6.5 and Table 13.1.1 Alarms and safety arrangements. These requirements are applicable to pump rooms where pumps for cargo, such as cargo pumps, stripping pumps, pumps for slop tanks, pumps for COW or similar pumps are provided and not for pump rooms intended solely for ballast transfer. See also Pt 5, Ch 13, 1.6 Cargo pump-room 1.6.9.

1.6.5 A system for continuously monitoring the concentration of hydrocarbon gases and oxygen within the cargo pump room is to be fitted. Sampling points are to be located in positions such as in way of the bottom of the pump room and just below the main deck where potentially dangerous concentrations of hydrocarbon gases, or lack of oxygen, may be readily detected. This requirement is not applicable for Type N-open tankers.

1.6.6 Visual and audible alarms for the hydrocarbon concentration as per Table 13.1.1 Alarms and safety arrangements are to be fitted in the wheelhouse and pump room. At hydrocarbon alarm the gas discharge installation on Type G tankers is to be stopped. For all other tankers the loading or discharging installation is to be stopped.

1.6.7 An optic and acoustic alarm is to be provided in the wheelhouse and on deck indicating malfunctioning of the gas detection installation.

1.6.8 All cargo piping, including the stripping pipes for Type C and N tankers, except the N-open type, are to be provided with a valve secured to the bulkhead capable of being operated from an accessible position above the weather deck. See also 3.7. Control of the pump capacity is to be arranged also from this position.

1.6.9 Where items of equipment other than described in Table 13.1.1 Alarms and safety arrangements are located in the pump room and are driven by shafts passing through bulkheads, the potential risk of ignition of hydrocarbon gas is to be assessed and proposals for mitigation submitted to LR for consideration.

1.6.10 All cargo piping (suction and discharge side) for Type G tankers are to pass through the deck above the pump room the necessary control of valves in the pump room and control of the pump capacity is to be arranged from above the weather deck.

1.7.1 For all tanker Types, the requirements of Pt 5, Ch 13, 1.7 Cargo pump-room ventilation 1.7.2 are to be complied with. Natural ventilation is acceptable for Type N-open tankers.

1.7.2 Cargo pump-rooms and other enclosed spaces which contain cargo handling equipment, and to which regular access is required during cargo handling operations, are to be provided with permanent ventilation systems of the mechanical extraction type.

1.7.3 The ventilation system is to be capable of being operated from outside the compartment being ventilated, and the following notices are to be fixed near the entrance:

1.7.4 Before entering the space the ventilation system is to be in operation for at least 30 minutes.

1.7.5 The ventilation system is to start automatically in case of high alarm hydrocarbon concentration.

1.7.6 The ventilation system is to be capable of at least 30 air changes per hour, based on the gross volume of the pump-room.

1.7.7 The ventilation system is to be suitable for operation in a dangerous atmosphere.

1.7.8 The ventilation ducting is to be arranged to permit extraction from the vicinity of the pump-room bilges. Air intakes are to be so arranged in the upper part of the pumproom to minimise the possibility of recycling hazardous vapour from any ventilation discharge opening. Vent exits are to be arranged to discharge to a safe place on the open deck and comply with the requirements of Pt 5, Ch 13, 1.7 Cargo pump-room ventilation 1.7.11.

1.7.9 Renewable flame screens are to be provided in ventilation ducts.

1.7.10 Provision is to be made for closing the air intake and extraction ducts in case of fire. The means provided are to be capable of operation from the deck. This requirement is not applicable for Type N-open tankers.

1.7.11 Ventilation openings are to be arranged at a horizontal distance of not less than 6 m away from accommodation and service spaces outside the cargo zone. This requirement is not applicable for Type N-open tankers.

1.8.1 The air gap between impeller and housing of the fan is to be not less than 0,1 of the impeller shaft bearing diameter or 2 mm whichever is the larger, subject also to compliance with Pt 5, Ch 13, 1.8 Non-sparking fans for hazardous areas 1.8.2.(e). Generally, however, the air gap need be no more than 13 mm.

1.8.2 The following combinations of materials are permissible for the impeller and the housing in way of the impeller:

1. impellers and/or housings of non-metallic material, due regard being paid to the elimination of static electricity;

2. impellers and housings of non-ferrous metals;

3. impellers and housings of austenitic stainless steel;

4. impellers of aluminium alloys or magnesium alloys and a ferrous housing provided that a ring of suitable thickness of non-ferrous material is fitted in way of the impeller;

5. any combination of ferrous impellers and housings with not less than 13 mm tip clearance;

6. any combination of materials for the impeller and housing which are demonstrated as being sparkproof by appropriate rubbing tests.

1.8.3 The following combinations of materials for impellers and housings are not considered sparkproof and are not permitted:

1. impellers of aluminium alloy or magnesium alloy and a ferrous housing irrespective of tip clearance;

2. impellers of a ferrous material and housings made of an aluminium alloy, irrespective of tip clearance;

3. any combination of ferrous impeller and housing with less than 13 mm tip clearance, other than permitted by Pt 5, Ch 13, 1.8 Non-sparking fans for hazardous areas 1.8.2.(c).

1.8.4 Electrostatic charges both in the rotating body and the casing are to be prevented by the use of antistatic materials (i.e. materials having an electrical resistance between 5 x 10⁴ ohms and 10⁸ ohms), or special means are to be provided to avoid dangerous electrical charges on the surface of the material.

1.8.5 Evidence of satisfactory type testing of the complete fan, witnessed by a recognized Authority or by LR’s Surveyors is to be provided.

1.8.6 Protection screens of not more than 13 mm square mesh are to be fitted in the inlet and outlet of ventilation ducts to prevent the entry of objects into the fan housing.

1.8.7 The installation of the ventilation units on board is to be such as to ensure the safe bonding to the hull of the units themselves.

1.8.8 Non-sparking fans are not required for Type N-open tankers.

1.9.1 Penetrations through the bulkhead between the machinery space and the pump room/cofferdam in the cargo area, or the bulkhead between the machinery space and the hold spaces containing cargo tanks may be provided for electrical cables, hydraulic lines and piping for measuring, control and alarm systems, provided that the penetrations are of an approved gastight type.

1.9.2 For ships required to comply with the ADN Regulations penetrations through a bulkhead with an 'A-60' fire protection insulation according to Regulation 3 - Definitions, shall have an equivalent fire protection. See also Pt 5, Ch 13, 1.6 Cargo pump-room 1.6.2.

1.9.3 Pipes may pass through the bulkhead between the machinery space and the pump room/cofferdam in the cargo area, provided that these pipes are connecting mechanical equipment between the machinery space and the pump room/cofferdam and do not have any openings within the pump room/cofferdam.

1.9.4 Pipes from the machinery space led to the open may pass through the pump-room/cofferdam/wing tank in the cargo area or a hold space containing the cargo tanks to the open, provided that, within the spaces mentioned above, they are:

• of substantial wall thickness
• without flanged joints or openings
• as short as practicable.

1.10.1 Other enclosed spaces in the cargo zone not containing cargo handling equipment such as ballast pump rooms, etc. and to which regular access is required, are to be provided with permanent ventilation systems of the mechanical extraction type.

1.10.2 The ventilation system is to be capable of at least 20 air changes per hour, based on the gross volume of the service space.

1.10.3 The ventilation ducting is to be arranged to permit extraction from 50 mm above the bottom of the service space. For the arrangement of air intakes such as height and the required distances to tank hatches and safety valves, see Pt 4, Ch 4, 3.2 Hold spaces, cargo tanks and service spaces 3.2.10.

1.10.4 Mechanical ventilation fans are to be of the nonsparking type, see Pt 5, Ch 13, 1.8 Non-sparking fans for hazardous areas.

1.10.5 Provision is to be made for closing the air intake and extraction ducts in case of fire. The means provided are to be capable of operation from the deck.

1.10.6 For type N-open tankers natural ventilation is acceptable.