Watertight doors should be tested by water pressure to a
head of water measured from the lower edge of the door opening to
the bulkhead deck or the freeboard deck, or to the most unfavourable
final or intermediate waterplane during flooding, whichever is greater.
Large doors, hatches or ramps on passenger and cargo ships,
of a design and size that would make pressure testing impracticable,
may be exempted from regulation 16.2, provided it is demonstrated
by calculations that the doors, hatches or ramps maintain watertightness
at design pressure with a proper margin of resistance. Where such
doors utilize gasket seals, a prototype pressure test to confirm that
the compression of the gasket material is capable of accommodating
any deflection, revealed by the structural analysis, should be carried
out. After installation every such door, hatch or ramp should be tested
by means of a hose test or equivalent.
Note See notes under regulation 13 for additional information
regarding the treatment of steps in the bulkhead deck of passenger
ships. See notes under regulation 13-1 for additional information
regarding the treatment of steps in the freeboard deck of cargo ships.