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

9.1.1 Where arrangements for cooling cargo, Ro-Ro or special category spaces below the bulkhead or freeboard deck, or fire-fighting by means of fixed spraying nozzles or by flooding of these spaces with water are provided, the following provisions are to apply, see also IMO guidelines (MSC.1/Circular.1320 – Guidelines for the Drainage of Fire-Fighting Water From Closed Vehicle and Ro-Ro Spaces and Special Category Spaces of Passenger and Cargo Ships – (11 June 2009)):

1. The drainage system is to be sized to remove no less than 125 per cent of the combined capacity of both the water spraying system pumps and the required number of fire hose nozzles.

2. The drainage system valves are to be operable from outside the protected space at a position in the vicinity of the extinguishing system controls.

3. Adequately sized bilge wells are to be located at the side shell of the ship at a distance from each other of not more than 40 m in each watertight compartment, the bilge wells should be uniformly distributed fore and aft, see also Pt 3, Ch 12, 4.1 General 4.1.4 and Pt 4, Ch 2, 10.2 Openings in main vehicle deck. For cargo ships only, if this is not possible, the free surface effect on the ship’s stability is to be determined and submitted to the Flag Administration for appraisal.

9.1.2 If drainage of vehicle or cargo 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 Pt 3, Ch 12, 4.1 General 4.1.3. If led to a closed drain tank, this tank is to be located outside the machinery spaces and provided with a vent pipe leading to a safe location on the open deck. See also Pt 4, Ch 2, 10.2 Openings in main vehicle deck.

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

9.1.4 On ships with closed vehicle spaces, ro-ro spaces and special category spaces, means are to be provided to prevent the blockage of drainage systems from these spaces.