Section 9 Additional requirements relating to fixed pressure water spray fire-extinguishing systems

9.1.1 Systems are to be designed in accordance with the requirements of an appropriate international or naval standard.

9.1.2 Documentation is to be submitted in accordance with Vol 2, Pt 7, Ch 1, 2.1 Documentation required for design review, including a system design description and pipe flow calculations.

9.2.1 Where arrangements for cooling underdeck hold spaces, or fire-fighting by means of fixed spraying nozzles or by flooding of spaces with water are provided, the drainage arrangements are to be such as to be effective under all normal angles of heel and trim. The following provisions are also to be satisfied:

1. The drainage system is to be sized to remove no less than 125 per cent of the maximum water input through fire fighting systems on each side of the ship in each fire zone.

2. The drainage system valves are to be operable from outside the protected space. The operating position is to be in the vicinity of the extinguishing system controls where such controls are fitted.

3. Adequately sized bilge wells are to be located at the side shell of the ship at a distance of not more than 40 m in each watertight compartment, see also Vol 1, Pt 3, Ch 4, 8.1 General 8.1.4 and Vol 1, Pt 4, Ch 3, 2.11 Openings in main vehicle deck. In ships other than NS3 Ships and vessels designed to carry less than 50 embarked personnel, if it is not possible to locate the bilge wells as required, the free surface effect on the ship's stability is to be determined.

9.2.2 If drainage of aircraft, vehicle or hold spaces is by gravity, the drainage is to be led directly overboard or to a closed drain tank. If led overboard the scuppers are to comply with Vol 1, Pt 3, Ch 4, 8.1 General 8.1.3. If led to a closed drain tank, this tank is to be located outside the machinery spaces and provided with a dedicated vent pipe leading to a safe location on the open deck. See also Vol 1, Pt 4, Ch 3, 2.11 Openings in main vehicle deck.

9.2.3 Drainage from a space into bilge wells in a lower space is only permitted if that space satisfies the same requirements as the space above.

9.2.4 Magazines may have specific requirements for water input for fire protection purposes and the water drainage arrangements are to take these requirements into account. See Vol 1, Pt 4, Ch 1, 6.9 Fire protection and Vol 2, Pt 7, Ch 5, 10.2 Pump units.