A seawater pump which supply the ship fire main when the machinery space pump is not available.
According to SOLAS (Chapter II-2: Construction, Part A, Reg. 4) in cargo ships of 2,000 gross tonnage and upwards, the space containing an emergency fire pump shall not be contiguous to the engine room. There are ships where meeting this requirement is not practical and SOLAS allows using such solution in special cases. Unfortunately, shipyards often use this possibility, even if arrangement of ship enables the correct solution. As the result, there are many new ships with the fire pump located just abaft the aft engine room bulkhead. In addition, the emergency fire pump sea suction and all suction piping are located in the machinery space. SOLAS allows only in exceptional cases short length of the emergency fire pump suction piping can penetrate the machinery space if enclosed in substantial steel casing. Unfortunately, such situation is tolerated by Classification Societies, which accept insulation of suction pipe to A-60 standard in lieu of steel casing. The philosophy of Classification Societies regarding the seawater inlet valve operation differs: one requires valve to be remote operated, other requires valve to be locked in open position.
The arrangement of a container ship enables the correct solution without any compromises to safety: location of the emergency fire pump and its sea suction in the bow thruster room fully complies with SOLAS requirements. In addition such solution eliminates troublesome external piping. Much easier connections to the fire mains in underdeck passageways can be arranged with better protection against corrosion and frost.