1.1 The design, materials and construction of
all watertight closures such as doors, hatches, sidescuttles, gangway and cargo ports,
valves, pipes, ash-chutes and rubbish-chutes referred to in these regulations shall be
to the satisfaction of the Administration.
1.2 Such valves, doors, hatches and mechanisms
shall be suitably marked to ensure that they may be properly used to provide maximum
safety.
1.3 The frames of vertical watertight doors
shall have no groove at the bottom in which dirt might lodge and prevent the door
closing properly.
2 Watertight doors and hatches shall be tested by water
pressure to the maximum head of water they might sustain in a final or intermediate
stage of flooding. For cargo ships not covered by damage stability requirements,
watertight doors and hatches shall be tested by water pressure to a head of water
measured from the lower edge of the opening to one metre above the freeboard deck. Where
testing of individual doors and hatches is not carried out because of possible damage to
insulation or outfitting items, testing of individual doors and hatches may be replaced
by a prototype pressure test of each type and size of door or hatch with a test pressure
corresponding at least to the head required for the individual location. The prototype
test shall be carried out before the door or hatch is fitted. The installation method
and procedure for fitting the door or hatch on board shall correspond to that of the
prototype test. When fitted on board, each door or hatch shall be checked for proper
seating between the bulkhead, the frame and the door or between deck, the coaming and
the hatch.