10.1.1 The mandatory instruments referenced in
section 2 require the final waterline, taking into account sinkage,
heel and trim, to be below the lower edge of any opening through which
progressive flooding may take place. Such openings shall include air
pipes (irrespective of closing devices) and those which are closed
by means of weathertight doors or hatch covers and may exclude those
openings closed by means of watertight manhole covers and flush scuttles,
small watertight cargo tank hatch covers which maintain the high integrity
of the deck, remotely operated watertight sliding doors, and sidescuttles
of the non-opening type.
10.1.2 Within the required range of residual stability,
the immersion of any of the openings listed above and other openings
capable of being closed weathertight may be permitted.
10.1.3 In the final equilibrium condition watertight
escape hatches should not be submerged below the equilibrium damage
waterline and should be treated as weathertight openingsfootnote.
10.1.4 For an emergency generator room the lowest
point of the room should remain above the final equilibrium damage
waterline. Any opening leading to this room should be treated as unprotected
or weathertight, as applicable.
10.1.5 The following principles apply:
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.1 Watertight doors under the final waterline
after flooding
All watertight doors under the final
waterline after flooding should be remotely operated sliding watertight
doors. Installation of a hinged watertight door (e.g. between the
steering gear compartment and engine room) is subject to acceptance
by the Administration.
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.2 Progressive flooding due to damage or submersion
of air pipes
Progressive flooding may be accepted subject
to the air pipes leading to relatively small compartments which are
progressively flooded in a predictable and sequential manner in which
all intermediate stages of flooding (with the exception on no progressive
flooding) and the final stage of flooding meet the required stability
criteria.
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.3 Watertight doors on the aft wall of forecastle
under the final waterline after flooding.
10.1.6 Hinged watertight doors at the aft bulkhead
of a forecastle space are permitted to be submerged after damage only
when possible progressive flooding is limited to one relatively small
compartment which is progressively flooded in a predictable and sequential
manner in which all intermediate stages of flooding (with the exception
of no progressive flooding) and the final stage of flooding meet the
required stability criteria. No further progressive flooding is permitted
beyond the initial flooding of the forecastle. This approach is only
permitted after all other options, such as increasing the sill height,
relocating the door, only providing access from above, have been shown
to be unworkable in practice.