The Merchant Shipping (Passenger Ship Construction: Ships of Classes I, II and II(A)) Regulations 1998

Construction and testing of watertight decks, trunks etc.

18.—(1) Watertight decks, trunks, tunnels, duct keels and ventilators shall be of the same strength as watertight bulkheads at corresponding levels. The means used for making them watertight, and the arrangements adopted for closing openings in them, shall be to the satisfaction of the Certifying Authority. Watertight ventilators and trunks shall be carried at least up to the bulkhead deck.

(2) Where a ventilation trunk passing through a structure penetrates the bulkhead deck, the trunk shall be capable of withstanding the water pressure that may be present within the trunk, assuming that the maximum heel angle allowable during intermediate stages of flooding shall be the angle specified in Schedule 1 of Merchant Shipping Notice MSN 1698 (M).

(3) Where all or part of the penetration of the bulkhead deck is on the main ro-ro deck, the trunk shall be capable of withstanding impact pressure due to internal water motions (sloshing) of water trapped on the ro-ro deck.

(4) In ships constructed before 1st July 1997, the requirements of paragraph (2) shall apply not later than the date of the first periodic survey after 1st July 1997 or the date on which these Regulations come into force whichever is later.

(5) After completion, a hose or flooding test shall be applied to watertight decks and a hose test to watertight trunks, tunnels and ventilators.