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 Administration. Watertight ventilators
and trunks shall be carried at least up to the bulkhead deck in passenger
ships and up to the freeboard deck in cargo ships.
2 In passenger ships, where a ventilation trunk passing
through a structure penetrates a watertight area of the bulkhead deck, the trunk shall
be capable of withstanding the water pressure that may be present within the trunk,
after having taken into account the maximum heel angle during flooding, in accordance
with regulation
7-2.
3 In ro-ro passenger ships, 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 After completion, a hose or flooding test shall
be applied to watertight decks and a hose test to watertight trunks,
tunnels and ventilators.