Part 4 Vessel Systems and Machinery Chapter 7 Fire Safety Systems Section 3 Fire-extinguishing Systems and Equipment 4-7-3

514 ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS . 2013

1.7 Diameter and Pressure in the Fire Main 1.7.1 Fire Main Diameter

The diameter of the fire main and water service pipes is to be sufficient for the effective distribution of the maximum required discharge from two fire pumps operating simultaneously. However, the diameter need only be sufficient for the discharge of 140 m3/hour (616 gpm).

1.7.2 Fire Main Pressure (1 July 2002) With the two pumps simultaneously delivering through nozzles specified in 4-7-3/1.15 the quantity of water specified in 4-7-3/1.7.1, through any adjacent hydrants, the following minimum pressures are to be maintained at all hydrants:

i) Vessels of 6,000 gross tonnage and upwards: 0.27 N/mm2 (2.8 kgf/cm2, 40 psi);

ii) Vessels less than 6,000 gross tonnage: 0.25 N/mm2 (2.6 kgf/cm2, 37 psi).

1.7.3 Fire Hose Handling The maximum pressure at any hydrant is not to exceed that at which the effective control of a fire hose can be demonstrated.

1.9 Number and Position of Hydrants (1 July 2002) The number and position of hydrants are to be such that at least two jets of water not emanating from the same hydrant, one of which is to be from a single length of hose, may reach any part of the vessel normally accessible to the passengers or crew while the vessel is being navigated and any part of any cargo space when empty, any ro-ro cargo space or any vehicle space in which latter case the two jets are to reach any part of such space, each from a single length of hose. Furthermore, such hydrants are to be positioned near the accesses to the protected spaces.

1.11 Pipes and Hydrants (1 July 2002) 1.11.1 General (2006)

Materials readily rendered ineffective by heat are not to be used for fire mains and hydrants unless adequately protected. The pipes and hydrants are to be so placed that the fire hoses may be easily coupled to them. The arrangement of pipes and hydrants is to be such as to avoid the possibility of freezing. Suitable drainage provisions are to be provided for the fire main piping. Isolation valves are to be installed for all open deck fire main branches used for purpose other than fire fighting. In vessels where deck cargo may be carried, the positions of the hydrants are to be such that they are always readily accessible and the pipes are to be arranged as far as practicable to avoid risk of damage by such cargo. Unless one hose and nozzle is provided for each hydrant in the vessel, there are to be complete interchangeability of hose couplings and nozzles.

Materials used for the firemain, hydrants and firemain components (such as valves, expansion joints, fittings, gaskets, etc., including filler materials used for associated methods of attachment) are not considered “readily rendered ineffective by heat”, provided the components made of such materials are capable of passing a recognized fire test acceptable to ABS.

1.11.2 Hydrant Valves A valve is to be fitted to serve each fire hydrant so that any fire hose may be removed while the fire pumps are in operation.

1.11.3 Isolating Valves and Pipes Routing Isolating valves to separate the section of the fire main within the machinery space containing the main fire pump or pumps from the rest of the fire main are to be fitted in an easily accessible and tenable position outside of the machinery spaces. The fire main is to be so arranged that when the isolating valves are shut, all of the hydrants on the vessel, except those in the machinery space referred to above, can be supplied with water by another fire pump or an emergency fire pump.

This requirement applies to a machinery space of category A only. Any part of the fire main routed through a machinery space of category A is to be fitted with isolating valves outside of the space.