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Fire protection and Fire extinction on Liquefied Gas Carriers

The provisions of this article about Fire Protection are applicable to ships carrying flammable products and should be applied in conjunction with part D of chapter II-1 of the 1983 SOLAS amendments.

Electric Installations

Electrical installations are to be such as to minimize the risk of fire and explosion from flammable products Refer to the relevant standarts of the International Electrotechnical Commission, in particular publication 60092-502.x. Electrical installations complying with this article need not be considered as a source of ignition for the purpose of “Arrangement of the gas carrier ships”Ship arrangement. The requirements of Rules for Electrical Installations (Part 1, Vol. IV), are to be complied with.

Electrical equipment or wiring is not to be installed in gas-dangerous spaces or zones unless essential for operational purposes. Electrical equipment, cables and wiring should not be installed in hazardous locations unless it conforms with the standards not inferior to those acceptable to the Organization Refer to the standarts published by the International Electrotechnical Commission , IEC 60092-502:1999 ‘Electrical installations in ships – Tankers’x. 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 Society, to ensure that an equivalent level of safety is assured.

Where electrical equipment is installed in gas-dangerous spaces or zones as provided above, it must be to the satisfaction of the Society and approved by the relevant Authorities recognized by the Society for operation in the flammable atmosphere concerned.

Bonding

Independent cargo tanks are to be electrically bonded to the hull.All gasketed cargo pipe joints and hose connections are to be electrically bonded. (See also “Piping System of pressure vessels on gas tankers”Piping system – general)

Fire Protection and Fire Extinction

Fire safety requirements

The requirements for tankers in SOLAS Chapter II-2 (see Section 1, C.35) apply to liquefied gas tankers, irrespective of tonnage including ships of less than 500 gross tonnage, except that:

1 regulations “Cargo containment system of gas vessel”Allowable stresses and corrosion allowance and “Cargo containment system of gas carrier”Allowable stresses do not apply;

2 regulation 10.2 as applicable to cargo ships and regulations 10.4 and 10.5 shall apply as they would apply to tankers of 2 000 gross tonnage and over;

3 regulation 10.5.6 should apply to ships of 2 000 gross tonnage and over;

4 the following regulations of SOLAS chapter II-2 related to tankers do not apply and are replaced by section and paragraph of the Rules as detailed below;

RegulationReplaced by
10.1011.6
4.5.1.1 and 4.5.1.2“Arrangement of the gas carrier ships”Ship arrangement
4.5.5 and 10.8“Water spray system” and “Dry chemical powder fire extinguishing systems”
10.9“Cargo compressor and pump rooms”

5 regulations 13.3.4 and 13.4.3 should apply to ships of 500 gross tonnage and over.

All sources of ignition are to be excluded from spaces where flammable vapour may be present except as otherwise provided in “Electric Installations” and “Cargo LNG as fuel”Use of Cargo as Fuel on Gas Tankers. The provisions of paragraph “Fire safety requirements” apply in conjunction with “Arrangement of the gas carrier ships”Ship arrangement.

For the purposes of fire fighting, any open deck areas above cofferdams, ballast or void spaces at the after end of the aftermost hold space or at the forward end of the forward most hold space are to be included in the cargo area.

The structural fire protection provisions of Chapter II-2 of the 1974 SOLAS Convention, applicable to liquefied gas carriers, are given in Rules for Hull (Part 1, Vol. II) Sec. 22, F.

Fire water main equipment

All ships, irrespective of size, carrying products which are subject to these Rules shall comply with the requirements of Regulations II-2/10.2, II-2/10.4 and II-2/10.5 of the 1974 SOLAS Convention, except that the required fire pump capacity and fire main and water service pipe diameter shall not to be limited by the provisions of Regulations II-2/10.2.2.4.1 and II-2/10.2.1.3 when the fire pump and fire main are used as part of the water spray system as permitted below. In addition, the requirements of Regulation II-2/10.2.1.6 are to be met at a pressure of at least 5,0 bar gauge.

Regarding Regulations 10.2.2.4.1 and 10.2.1.3 of Chapter II-2 of the 1974 SOLAS Convention see Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, E.1 and Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, E.2.

The arrangements are to be such that at least two jets of water can reach any part of the deck in the cargo area and those portions of the cargo containment system and tank covers above the deck. The necessary number of fire hydrants shall be located to satisfy the above arrangements and to comply with the requirements of Regulation II-2/10.2.1.5.1 and II-2/10.2.3.3 of the 1974 SOLAS Convention, with hose lengths as specified in Regulation II-2/10.2.3.1.1.

Regarding Regulations II-2/10.2.1.5.1 and II-2/10.2.3.3 of the 1974 SOLAS Convention see also Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, E.2.4 and Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, E.2.6.

Stop valves are to be fitted in any cross-over provided and in the fire main or mains at the poop front and at intervals of not more than 40 m between hydrants on the deck in the cargo area for the purpose of isolating damaged sections of the main.

All water nozzles provided for firefighting use are to be of an approved dual-purpose type capable of producing either a spray or a jet. All pipes, valves, nozzles and other fittings in the fire fighting systems shall be resistant to corrosion by sea water, for example by galvanized pipe, and to the effect of fire.

Where the ship’s engine room is unattended, arrangements are to be made to start and connect to the fire main at least one fire pump by remote control from the navigating bridge or other control station outside the cargo area.

Water spray system

On ships carrying flammable of toxic products or both, a water spray system for cooling, fire prevention and crew protection are to be installed to cover:

  1. exposed cargo tank domes and any exposed parts of cargo tanks;
  2. exposed on-deck storage vessels for flammable or toxic products;
  3. cargo liquid and vapour discharge and loading and any other areas where essential control valves are situated which shall be at least equal to the area of the drip trays provided;
  4. boundaries of superstructures, deckhouses normally manned, cargo compressor rooms, store-rooms containing high fire risk items and cargo control rooms all facing the cargo area. Boundaries of unmanned forecastle structures not containing high fire risk items do not require water spray protection.

The system is to be capable of covering all areas mentioned in list above with a uniformly distributed water spray of at least 10 R/m2 per minute for horizontal projected surfaces and 4 R/m2 per minute for vertical surfaces. For structures having not clearly defined horizontal or vertical surfaces, the capacity of the water spray system is to be determined by the greater of the following:

  1. projected horizontal surface multiplied by 10 R/m2 per minute;
  2. actual surface multiplied by 4 R/m2 per minute.

On vertical surfaces, spacing of nozzles protecting lower areas may take account of anticipated run-down from higher areas. Stop valves are to be fitted at intervals in the spray main for the purpose of isolating damaged sections. Alternatively, the system may be divided into two or more sections which may be operated independently provided the necessary controls are located together, aft of the cargo area. A section protecting any area included in list above is to cover the whole of the athwartship tank grouping which includes that area.

The capacity of the water spray pump shall be sufficient to deliver the required amount of water to all areas simultaneously or, where the system is divided into sections, the arrangements and capacity shall be such as to simultaneously supply water to any one section and the surfaces specified above.

Alternatively, the main fire pumps may be used for this service provided that their total capacity is increased by the amount needed for the spray system. In either case, a connection, through a stop valve, is to be made between the fire main and water spray main outside the cargo area.

Subject to the approval of the Society, water pumps normally used for other services may be arranged to supply the water spray main.

All pipes, valves, nozzles and other fittings in the water spray systems shall be resistant to corrosion by sea water, for example by galvanized pipe, and to the effect of fire.

Remote starting of pumps supplying the water spray system and remote operation of any normally closed valves in the system shall be arranged in suitable locations outside the cargo area, adjacent to the accommodation spaces and readily accessible and operable in the event of fire in the areas protected.

Dry chemical powder fire extinguishing systems

Ships intending to carry flammable products are to be fitted with a fixed dry chemical powder type extinguishing systems for the purpose of fighting fire on the deck in the cargo area and bow or stern cargo handling areas if applicable. The system and the dry chemical powder shall be adequate for this purpose and satisfactory to the Society.

Drawings of the system and details of the dry chemical powder are to be submitted to the Society for approval.

The system is to be capable of delivering powder from at least two hand hose lines or a combination monitor/hand hose line(s) to any part of the above-deck exposed cargo area including above-deck product piping. The system shall be activated by an inert gas, such as nitrogen, used exclusively for this purpose and stored in pressure vessels adjacent to the powder containers.

The system for use in the cargo area shall consist of at least two independent self-contained dry chemical powder units with associated controls, pressurizing medium fixed piping, monitors or hand hose lines. For ships with a cargo capacity of less than 1 000 m3 only one such unit need be fitted subject to the approval of the Society. A monitor is to be provided and so arranged as to protect the cargo loading and discharge manifold areas and be capable of actuation and discharge locally and remotely.

Fire on the ship
Chemical powder usage in firefighting

The monitor is not required to be remotely aimed if it can deliver the necessary powder to all areas of coverage from a single position. All hand hose lines and monitors shall be capable of actuation at the hose storage reel or monitor. At least one hand hose line or monitor is to be situated at the after end of the cargo area.

A fire extinguishing unit having two or more monitors, hand hose lines, or combinations thereof, shall have independent pipes with a manifold at the powder container, unless a suitable alternative means is provided to ensure proper performance as approved by the Society. Where two or more pipes are attached to a unit the arrangement shall be such that any or all of the monitors and hand hose lines are capable of simultaneous or sequential operation at their rated capacities.

The capacity of a monitor shall be not less than 10 kg/s. Hand hose lines shall be non-kinkable and be fitted with a nozzle capable of on/off operation and discharge at a rate not less than 3,5 kg/s. The maximum discharge rate shall be such as to allow operation by one man. The length of a hand hose line shall not exceed 33 m. Where fixed piping is provided between the powder container and a hand hose line or fluidized state during sustained or intermittent use, and which can be purged of powder when the system is shut down. Hand hose lines and nozzles shall be of weather resistant construction or stored in weather resistant housing or covers and be readily accessible.

A sufficient quantity of dry chemical powder is to be stored in each container to provide a minimum 45 seconds discharge time for all monitors and hand hose lines attached to each powder unit. Coverage from fixed monitors shall be in accordance with the following requirements:

  • Capacity of fixed monitors [kg/s] each: 10 25 45;
  • Maximum distance of coverage [m]: 10 30 40

Hand hose lines shall be considered to have a maximum effective distance of coverage equal to the length of hose. Special consideration is to be given where areas to be protected are substantially elevated above the monitor or hand hose reel locations.

Ships fitted with bow or stern loading and discharge arrangements are to be provided with an additional dry chemical powder unit complete with at least one monitor and one hand hose line complying with the requirements of information above. This additional unit is to be located to protect the bow or stern loading and discharge arrangements. The area of the cargo line forward or aft of the cargo area shall be protected by hand hose lines.

Cargo compressor and pump rooms

The cargo compressor and pump room of any ship is to be provided with a carbon dioxide system as specified in Regulation II-2/10.9.1.1ofthe 1974 SOLAS Convention see also Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, G. A notice is to be exhibited at the controls stating that the system is only to be used for fire-extinguishing and not for inerting purposes, due to the electrostatic ignition hazard. The alarms referred to in Regulation II-2/10.9.1.1.1 of the 1974 SOLAS Convention see also Part Rules for Machinery Installations (Part 1, Vol. III) Sec. 12, G.7.1 are to be certified safe for use in a flammable cargo vapour-air mixture.

For the purpose of this requirement, an extinguishing system is to be provided which is suitable for machinery spaces. However, the amount of carbon dioxide gas carried shall be sufficient to provide a quantity of free gas equal to 45 % of the gross volume of the cargo compressor and pump rooms in all cases.

Cargo compressor and pump rooms of ships which are dedicated to the carriage of a restricted number of cargoes are to be protected by an appropriate fire-extinguishing system approved by the Society.

Fire-Fighter’s outfits

Every ship carrying flammable products shall carry fire-fighter’s outfits complying with the requirements of Regulation II-2/10.10 of the 1974 SOLAS Convention as follows:

Total cargo capacityNumber of outfits
≤ 5 000 m34
> 5 000 m35

Additional requirements for safety equipment are given in “Personal protective equipment”Personal protection of crew on Gas Carriers.

Any breathing apparatus required as part of a fire-fighter’s outfit should be a self-contained air breathing apparatus having a capacity of at least 1200 R of free air.

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