Section
2 Fire and gas alarm indication and control systems
2.1 General requirements
2.2 Fire and gas detection alarm panels and
sensors
2.2.1 The requirements for fire detection alarms panels and sensors are given
in Pt 6, Ch 1, 2.8 Fire detection and fire alarm systems of the Rules and Regulations for the
Classification of Ships (hereinafter referred to as the Rules for Ships).
These Rules are also to be complied with where applicable for gas detection alarms
panels and sensors and fire detection alarms panels and sensors specific to the
unit’s requirements. For units containing drilling facilities, specific reference
should be made to the requirements of the Chapter 9 - Fire Safety, regarding fire and
gas detection. For units with liquefied gas storage in bulk and/or vapour discharge
and loading manifolds/facilities, see
Pt 11, Ch 13, 1.6 Gas detection.
2.2.3 A fire and gas detection indicating panel is to be located at the
centralised control station. A repeater panel is to be provided at a location which
is readily accessible to responsible members of the crew at all times, at the fire
control station, if fitted, and at, or adjacent to, the workstation for navigation
and manoeuvring or the workstation for safety, on the navigating bridge, if fitted.
The main panel and the fire-control station repeater are to indicate the source of
the fire in accordance with arranged fire zones by means of a visual signal. Any
other repeater panel(s) should indicate the general area of the fire zones
affected.
2.2.4 The activation of any detector or manually operated call point shall
initiate a visual and audible fire and gas detection alarm signal at the alarm and
repeater panels. If the signal(s) has not been acknowledged within 2 minutes, an
audible fire and gas alarm, having a characteristic tone, distinguishable from any
other alarm, is to be automatically and immediately audible in all parts of the
navigating bridge, if fitted, the workstations for navigation and manoeuvring, the
fire control station, if fitted, all accommodation areas (with the exception, on
accommodation units, of those for offshore personnel), and machinery spaces. The
alarm need not be an integral part of the detection system.
2.2.5 In addition to the areas required by the Rules for Ships, facilities are
to be provided in the fire and gas detection system to initiate manually the alarm
referred to in Pt 7, Ch 1, 2.2 Fire and gas detection alarm panels and sensors 2.2.4 from the following locations:
- Accommodation areas.
- The Unit Manager’s office.
- Control stations in machinery and process areas.
- The main control station or fire-control station, if
fitted.
- Throughout the installation in accordance with the defined fire
and gas detection philosophy.
2.2.6 Fire and gas detection and alarm systems are to be provided with an
emergency source of electrical power as required by Pt 6, Ch 2, 3 Emergency source of electrical power, and are also to be connected to the
main source of electrical power, with automatic changeover facilities located in, or
adjacent to, the main fire detection indicator panel, see also
Pt 6, Ch 2, 1.13 Bonding for the control of static electricity. Reference should also be made to
the guidance given in ISO 13702 to the supply capacity of UPS systems to defined
emergency/critical facilities for the installation or unit. Failure of any power
supply is to initiate an audible and visual alarm.
2.2.7 Fire and gas detectors are to be grouped as appropriate into zones
conforming to passive fire protection boundaries and/or safe/hazardous area
boundaries, as defined in Pt 7, Ch 2 Hazardous Areas and Ventilation. Further zones subdividing the above boundaries may
also be arranged, where beneficial. Factors influencing zone boundaries include
ventilation arrangements, bulkheads and the needs of the operating staff in locating
and dealing with fire and gas incidents.
2.2.8 A zone/section of fire detectors which covers a control station, a
service space or an accommodation space is not to include a machinery space or
process area.
2.2.9 Fire and gas detection systems control and indicator panels, repeater
panels, detectors heads, manual call points and short-circuit isolation units are to
be suitable for their intended purpose. Detectors shall be certified by a recognised
certifying authority for their intended purpose, where practicable, these should be
selected from LR’s List of Type Approved Products. Other bespoke design such
as control panels, etc. (see also
Pt 7, Ch 1, 2.6 Machinery space fire detection systems 2.6.3) should either be certified by a recognised
certifying authority for its intended purpose (where practicable, these should be
selected from LR’s List of Type Approved Products) or the design appraised by
Clasifications Register.
2.2.10 The fire detection system, and any associated gas detection for the
accommodation spaces, as required by Pt 7, Ch 1, 2.5 Additional requirements for accommodation fire detection systems, is to be integrated with, or suitably
interfaced with, the main fire and gas detection control and indication panel.
Similarly, any other permanent local fire and gas detection system is to be
integrated with, or suitably interfaced with, the main fire and gas detection
control and indication panel. Integrated systems should not result in reducing the
integrity of the individual functions.
2.2.11 When it is intended that a particular loop or detector is to be
temporarily switched off, reactivation need not be automatic after a preset time
provided alternative acceptable means are in place to ensure re-activation has been
successfully carried out.
2.2.12 Fire detector heads for the process and wellhead area, fusible plugs and
linear electric elements for direct actuating of the deluge system may be used to
supplement the automatic fire detection system.
2.2.14 Means are to be provided so that the sensitivity of gas detectors can be
readily tested in their mounted positions by the injection of span gas or other
equivalent method.
2.2.15 In addition to the fixed gas detection system, portable gas detectors of
each of the following types, together with any necessary test facilities for
checking their accuracy, are to be provided for all anticipated gas hazards
including the following:
- Hydrocarbon gas detectors range 0 to 100 per cent of the lower
explosive limit.
- Toxic gas detectors.
- Oxygen concentration meters.
2.2.16 A suitable fixed hydrocarbon gas detection system for adjacent ballast
tanks and void spaces of double-hull and double bottom spaces adjacent to hull
hydrocarbon storage tanks, including the forepeak tank and any other tanks and
spaces under the bulkhead deck adjacent to these hull hydrocarbon storage tank
spaces shall be fitted. The design of this fixed gas detection system shall be in
accordance with the requirements of Chapter 16 - Fixed Hydrocarbon Gas Detection Systems of the FSS Code - Fire Safety Systems – Resolution MSC.98(73).
2.3 Fire-extinguishing systems
2.3.2 The operational state of fire-extinguishing facilities, including
smothering gas, deluge, foam equipment, and fire water systems, are to be displayed
on the main control panel and the fire control point repeater panel, if fitted, as
follows:
- Charges of gas available for use, indication of zones into which
gas has been released, and reserve capacity in hand.
- Indication of zones in which water deluge has been
initiated.
- Liquid level in main installation (i.e. deck foam system, etc.)
foam concentrate tank(s) and status of foam concentrate pumps and
valves.
- Availability of fire pumps, indication of running and standby
sets and positions of associated valves.
- Operational state of sprinkler systems.
2.3.3 The provision of manual and automatic release facilities for
extinguishing media are to be designed to afford optimum protection to the
installation, while giving proper regard to the safety of personnel as follows:
- Generally, the release of asphyxiating gases
such as carbon dioxide should only be initiated locally by manual means
since it is necessary to ensure that the space to be dealt with has been
evacuated.
- Deluge systems and extinguishing gases which can be released
without introducing an unacceptable health risk should be capable of being
manually released locally and remotely at the fire and gas indication and
control panel and at the fire-control station, if fitted.
- Automatic release of a fire-fighting system (i.e. deluge
system, etc.) can be initiated by voting fire detectors or individual fire
detectors.
2.3.4 Fire pumps are to be provided with automatic and manual starting
facilities on the fire and gas detection indication and control panel. Automatic
starting is to be initiated by activation of fire detection heads, operation of any
manual call points or reduction of pressure in the fire main. Controls which start
the standby set in the event of starting or running failure of the duty set are to
be provided. Safeguards required in the event of flammable gas being detected in the
vicinity of the fire pump are detailed under Pt 7, Ch 1, 5.1 General requirements 5.1.9. Manual starting facilities are to be provided
adjacent to all fire pumps.
2.3.5 The design of extinguishing systems is to be in accordance with Chapter II-2 - Construction - Fire protection, fire detection and fire extinction, and FSS Code - Fire Safety Systems – Resolution MSC.98(73). However,
installations with liquefied gas storage in bulk and/or vapour discharge and loading
manifolds/facilities are, in general, to comply with the requirements of Pt 11, Ch 11 Fire Prevention and Extinction . For units containing drilling facilities, reference
should be made to the requirements of the Chapter 9 - Fire Safety.
- When the emergency fire pump is electrically driven, the power
is to be supplied by a source other than that supplying the main fire pumps.
This source is to be located outside the machinery spaces containing the
main fire pumps and their source of power and drive units, see also
Pt 6, Ch 2, 3 Emergency source of electrical power. See
also
Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power 3.7.9.
- The cables to the emergency fire pump are not to pass through
the machinery spaces containing the main fire pumps and their source of
power and drive units. The cables are to be of a fire-resistant type, where
they pass through other high fire risk areas.
- Where there are electrically driven refrigeration units for
carbon dioxide fire-extinguishing systems, one unit is to be supplied by the
main source of electrical power and the other unit from the emergency source
of electrical power. Exclusive circuits are to be used for the two units,
see also
Pt 6, Ch 2, 3.1 General. See
also
Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power 3.7.9.
- Each electrically driven carbon dioxide refrigeration unit is
to be arranged for automatic operation in the event of loss of the
alternative unit.
2.3.6 Fire and gas dampers and ventilation fans serving areas in which fire
has been detected and confirmed by group voting are to be shut down automatically.
Similar action is to be carried out prior to the release of extinguishing media.
Manual shut-down from the main control panel and the fire control position is also
to be available. The provision to close fire dampers manually from both sides of the
bulkhead or deck, the integrity of which they are intended to maintain in line with
the requirements of SOLAS and the MODU Code, should also be considered. To comply
with those requirements, provision of means to close fire and gas dampers from a
local position (such as, for instance, the space they serve) and a remote position
(such as, for instance, the space where the fan is located) would be acceptable.
Additionally:
- The electrical power required for the control and indication
circuits of fire and gas dampers is to be supplied from the emergency source
of electrical power. See also
Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power 3.7.9.
- The control and indication systems for the fire and gas dampers
are to be designed on the fail safe principle, with the release system
having a manual reset.
2.3.7 The electrical power required for the control, indication and alarm
circuits of fire doors is to be supplied from the emergency source of electrical
power. See also
Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power 3.7.9. The control and indication systems
for the fire doors are to be designed on the fail safe principle, with the release
system having a manual reset.
2.3.8 Automatic sprinkler systems are to be considered as part of the fire
detection system.
2.3.10 The main fire and gas panel and the fire control point repeater, if
fitted, are to indicate the location and zone/section of the sprinklers that have
been initiated and the status of the system, as follows:
- Low level and pressure in the standing fresh water pressure
tank.
- Start-up of the electrically driven pump which is brought into
action automatically by the pressure drop in the system, before the standing
fresh water charge in the pressure tank is completely exhausted.
- The status of the electrically driven or diesel-driven seawater
fire pumps, that are required to start up when the fresh water system is
exhausted.
2.4 Fire safety stops
2.4.1 Means of stopping all ventilating fans, with manual reset, are to be
provided, outside the spaces being served, at positions which will not readily be
cut off in the event of a fire. The provisions for machinery spaces are to be
independent of those for other spaces.
2.4.2 Machines driving forced and induced draught fans, and independently
driven pumps for lubricating, hydraulic or stored oil are to be fitted with remote
controls, with manual reset, situated outside the space concerned so that they may
be stopped in the event of fire arising in the space in which they are located.
2.4.3 Means of cutting off power to the galley, in the event of a fire, are to
be provided outside the galley exits, at positions which will not readily be
rendered inaccessible by such a fire.
2.4.4 Fire safety stop systems are to be designed on the fail safe principle or,
alternatively, the power supplies to, and the circuits of, the fire safety stop
systems are to be continuously monitored and an alarm initiated in the event of a
fault. Cables are to be of a fire-resistant type, see
Pt 6, Ch 2, 5.3 Isolation and switching 5.3.10 of the Rules for
Ships.
2.5 Additional requirements for
accommodation fire detection systems
2.5.4 Where the fire detection system does not include means of remotely
identifying each detector individually, a minimum of two zones/sections of detectors
is to serve cabin spaces and they are to be arranged one on each side of the unit.
Exceptionally, one zone/section of detectors may be permitted to serve both sides of
the unit and more than one deck where it is satisfactorily shown that the protection
of the unit against fire will not be reduced thereby.
2.5.5 Heat detectors used for the protection of accommodation spaces are to
operate before the temperature exceeds 78°C, but not until the temperature exceeds
54°C.
2.5.6 The permissible temperature of operation of heat detectors may be
increased by 30°C above the maximum deckhead temperature in drying rooms and other
accommodation spaces having a normal high ambient temperature.
2.5.7 The maximum spacing of detectors in the living quarters is to be in
accordance with Table 1.2.1 Maximum fire detector
spacing. Other spacing complying
with appropriate National Standards will be permitted.
Table 1.2.1 Maximum fire detector
spacing
Type of detector
|
Maximum floor area perdetector, in m2
|
Maximum distanceapart between centres,in metres
|
Maximum distanceaway from bulkheads,in metres
|
Heat
|
37
|
9
|
4,5
|
Smoke
|
74
|
11
|
5,5
|
2.6 Machinery space fire detection
systems
2.6.2 An audible fire alarm is to be provided having a characteristic tone
which distinguishes it from other audible warnings having lower priority. The
audible fire alarm is to be immediately audible at the main control station and at
all repeater stations. If the alarm is not accepted within two minutes, a general
alarm is to be initiated throughout the unit.
2.6.3 Fire detection control units, indicating panels, detectors, manual call
points and short-circuit isolation units are to be Type Approved. Whenever
practicable they should be selected from the List of Type Approved Products
published by Lloyd’s Register (LR). For addressable systems, which also require to
be Type Approved, see
Pt 6, Ch 1, 2.9 Programmable electronic systems – General requirements.
2.6.4 When it is intended that a particular loop is to be temporarily switched
off locally, this state is to be clearly indicated at the main fire detection
control panel.
2.6.5 It is to be demonstrated to the Surveyor’s satisfaction that detector
heads are so located that air currents will not render the system ineffective.
2.6.6 Except in spaces of restricted height and where their use is particularly
appropriate, detection systems using only heat (thermal) detectors shall not be
permitted.
2.6.7 For machinery spaces utilising smoke detection or a combination of smoke
and heat detection, the spacing of detectors should meet the guidance given in Table 1.2.1 Maximum fire detector
spacing for maximum fire detector
spacing. However greater spacing of smoke and heat fire detection than that detailed
in Table 1.2.1 Maximum fire detector
spacing may be implemented in areas
also provided with flame detector coverage.
2.7 Fire detection systems for other general
enclosed spaces (enclosed services spaces / control stations / corridors and
stairways)
2.8 Fire detection systems for topsides
utility modules (i.e. power generation, boilers, water injection etc.)
2.8.1 An automatic fixed fire detection system is to be fitted in topsides
utility modules where a credible fire risk has been identified. The automatic fire
detection system is to meet the requirements of Pt 7, Ch 1, 2.2 Fire and gas detection alarm panels and sensors and the additional requirements of Pt 7, Ch 1, 2.8 Fire detection systems for topsides utility modules (i.e. power generation, boilers, water injection etc.)
2.8.2 to Pt 7, Ch 1, 2.8 Fire detection systems for topsides utility modules (i.e. power generation, boilers, water injection etc.)
2.8.7 are to be satisfied.
2.8.2 An audible fire alarm is to be provided having a characteristic tone
which distinguishes it from other audible warnings having lower priority. The
audible fire alarm is to be immediately audible at the main control station and at
all repeater stations along with initiating the general alarm throughout the
unit.
2.8.3 Fire detection control units, indicating panels, detectors, manual call
points and short-circuit isolation units are to be Type Approved. Whenever
practicable they should be selected from the List of Type Approved Products
published by Lloyd’s Register (LR).
2.8.4 When it is intended that a particular detector is to be temporarily
switched off locally, this state is to be clearly indicated at the main fire
detection control panel.
2.8.5 If the utility module is of an open or partially open construction, flame
detection is to be provided. The number and position of utilised flame detectors is
to ensure an appropriate coverage of the fire risk associated with the utility
module.
2.8.6 Except in enclosed utility modules of restricted height and where their
use is particularly appropriate, detection systems using only heat (thermal)
detectors shall not be permitted.
2.8.7 For enclosed utility modules utilising smoke detection or a combination
of smoke and heat detection, the spacing of detectors should meet the guidance given
in Table 1.2.1 Maximum fire detector
spacing for maximum fire detector
spacing. However greater spacing of smoke and heat fire detection than that detailed
in Table 1.2.1 Maximum fire detector
spacing may be implemented in areas
also provided with flame detector coverage.
2.9 Fire and gas detection systems for
topsides hydrocarbon process modules
2.9.2 An audible fire and gas alarm is to be provided having a characteristic
tone which distinguishes it from other audible warnings having lower priority. The
audible fire and / or gas alarm is to be immediately audible at the main control
station and at all repeater stations along with initiating the general alarm
throughout the unit.
2.9.3 Fire and gas detection control units, indicating panels, detectors,
manual call points and short-circuit isolation units are to be Type Approved.
Whenever practicable they should be selected from the List of Type Approved Products
published by Lloyd’s Register (LR).
2.9.4 When it is intended that a particular detector is to be temporarily
switched off locally, this state is to be clearly indicated at the main fire and gas
detection control panel.
2.9.5 If the process module is of an open or partially open construction,
flame detection is to be provided. The number and position of utilised flame
detectors is to ensure an appropriate coverage of the fire risk areas associated
with the process module.
2.9.6 Except in enclosed process modules of restricted height and where their
use is particularly appropriate, fire detection systems using only heat (thermal)
detectors shall not be permitted.
2.9.7 For enclosed process modules utilising smoke detection or a combination
of smoke and heat fire detection, the spacing of fire detectors should meet the
guidance given in Table 1.2.1 Maximum fire detector
spacing for maximum fire detector
spacing. However greater spacing of smoke and heat fire detection than that detailed
in Table 1.2.1 Maximum fire detector
spacing may be implemented in areas
also provided with flame detector coverage.
2.9.8 The number and position of utilised gas detectors is to ensure an
appropriate coverage of the hydrocarbon leak risks associated with the process
module.
2.10 Fire and gas detection systems for
drilling areas on mobile offshore drilling units
2.10.2 An audible fire and gas alarm is to be provided having a characteristic
tone which distinguishes it from other audible warnings having lower priority. The
audible fire and / or gas alarm is to be immediately audible at the main control
station and at all repeater stations along with initiating the general alarm
throughout the unit.
2.10.3 Fire and gas detection control units, indicating panels, detectors,
manual call points and short-circuit isolation units are to be Type Approved.
Whenever practicable they should be selected from the List of Type Approved Products
published by Lloyd’s Register (LR).
2.10.4 When it is intended that a particular detector is to be temporarily
switched off locally, this state is to be clearly indicated at the main fire and gas
detection control panel.
2.10.5 If the drilling area is of an open or partially open construction, flame
detection is to be provided. The number and position of utilised flame detectors is
to ensure an appropriate coverage of the fire risk areas associated with the
drilling area.
2.10.6 Except in enclosed drilling modules of restricted height and where their
use is particularly appropriate, fire detection systems using only heat (thermal)
detectors shall not be permitted.
2.10.7 For enclosed drilling areas utilising smoke detection or a combination
of smoke and heat fire detection, the spacing of fire detectors should meet the
guidance given in Table 1.2.1 Maximum fire detector
spacing for maximum fire detector
spacing. However greater spacing of smoke and heat fire detection than that detailed
in Table 1.2.1 Maximum fire detector
spacing may be implemented in areas
also provided with flame detector coverage.
2.10.8 The number and position of utilised gas detectors is to ensure an
appropriate coverage of the hydrocarbon leak risks associated with the drilling
facilities.
2.10.10 For mobile offshore drilling units, fixed automatic combustible gas detection and
alarm systems are to be provided for the following areas:
- Cellar deck;
- Drill floor;
- Ventilation intake of positive pressure explosion-proof driller's cabin or
local equipment rooms etc.;
- Mud pit area;
- Shale shaker area;
- Enclosed spaces containing the open components of mud circulation system
from the bell nipple to the mud pits;
- Ventilation intakes of accommodation spaces;
- Ventilation intakes of enclosed machinery spaces contiguous to hazardous
areas and containing internal combustion engines, boilers, or non-explosion
proof electrical equipment, for example, such equipment in local equipment
rooms etc.;
- Air intakes to all combustion engines or machinery, including internal
combustion engines, boilers, compressors or turbines, located outside of an
enclosed machinery space;
- At each access door to accommodation spaces; and
- Near other openings, including emergency egress, of accommodation spaces,
regardless of whether these openings are fitted with self-closing and
gastight closing appliances.
2.10.11 For mobile offshore drilling units, fixed automatic combustible gas detection and
alarm systems are not required:
- Near access doors to accommodation spaces where these form part of an air
lock which is provided with a gas detection and alarm system between the two
doors of the air lock;
- Near emergency egress doors which are fitted with a mechanism to prevent use
other than in an emergency (e.g. doors fitted with security seals acting as
a deterrent but easily breakable in a real emergency.); and
- Near other openings which are provided with closing appliances of
non-opening type, e.g. bolted closed maintenance ways etc.
2.10.12 For mobile offshore drilling units, fixed automatic hydrogen sulphide gas detection
and alarm systems are to be provided for the following areas:
- Drill area;
- Mud processing area; and
- Well test area.
2.10.13 The hydrogen sulphide detection and alarm system is to clearly indicate where gas has
been detected, with the low level alarm indication set at 10 ppm hydrogen
sulphide.
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