8.1 The bilge pumping system should have a required
capacity to pump:
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.1 the maximum hourly rate of green water shipped
in seagoing conditions as established by the comprehensive model testing
specified;
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.2 an amount equal to rainfall of 100 mm/hour
regardless of the installation of rain covers;
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.3 the amount of shipped green water measured
during the seakeeping model tests for the dead ship condition in beam
seas, multiplied by safety factor 2;
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.4 four-thirds of the amount of water required
for fire-fighting purposes in the largest hold;
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.5 an amount equal to the capacity required for
ships with closed cargo holds,
whichever is the greater.
8.2 The pumping of hold bilges should be possible
by at least three bilge pumps.
8.3 At least one of these pumps should have a
capacity of not less than the required capacity as defined in 8.1 and should be dedicated to bilge
and ballast service only. It should be located in such a way that
it will not be affected by a fire or other casualty to the space containing
the pumps required in 8.4 below
or the space containing the main source of power and should be supplied
from the emergency switchboard required by regulation II-1/43 of SOLAS 1974, as amended.
8.4 The combined output of at least two further
pumps should not be less than the required capacity as defined in 8.1. These pumps should be supplied
from the main source of electrical power required by regulation II-1/41 of SOLAS 1974,
as amended, or any other source of power independent of the emergency
switchboard required by regulation
II-1/43 of SOLAS 1974, as amended.
8.5 The bilge pumping system, including the piping
system, should incorporate sufficient redundancy features so that
the system will be fully operational and capable of dewatering the
hold spaces at the required capacity in the event of failure of any
one system component.
8.6 The bilge pumping system should be arranged
to be effective within the limiting angles of inclination required
for the emergency source of electrical power by SOLAS 1974, as amended,
and bilge wells should be readily accessible for cleaning.
8.7 All open cargo holds should be fitted with
high bilge level alarms. The alarms should annunciate in the machinery
spaces and the manned control location and be independent of bilge
pump controls.
8.8 If the loss of suction prevents the proper
functioning of the bilge system, special measures to prevent this
should be considered, as for instance, the installation of level indicators.
8.9 Open cargo hold drain wells should be designed
to ensure unobstructed discharge of water and easy access for cleaning
under all conditions.
8.10 If provided, freeing ports should be fitted
on both sides of each open cargo hold, subject to the following:
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.1 the number, size and location of the freeing
ports on each side of each open hold should be sufficient to prevent
the accumulation of water above the level defined in 5.12;
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.2 efficient means of closure to prevent the accidental
ingress of water should be provided. Such means should be operated
from above the freeboard deck. In the case of a ship operating in
areas where icing is likely to occur, these arrangements should be
suitable to enable the ports to operate efficiently under such conditions.