10.6.1 Arrangements should be made for draining
any watertight compartment other than the compartments intended for
permanent storage of liquid. Where in relation to particular compartments
drainage is not considered necessary, drainage arrangements may be
omitted but it is to be demonstrated that the safety of the craft
will not be impaired.
10.6.2 Bilge pumping arrangements should be provided
to allow every watertight compartment other than those intended for
permanent storage of liquid to be drained. The capacity or position
of such compartments should be such that flooding thereof could not
affect the safety of the craft.
10.6.3 The bilge pumping system should be capable
of operation under all possible values of list and trim after sustaining
the postulated damage in 2.4.4 and 2.4.5.
The bilge pumping system should be so designed as to prevent water
flowing from one compartment to another.
10.6.4
-
(a) At least two pumps should be available for
bilge pumping of which at least one should be reserved solely for
bilge pumping duties. Any other pump of suitable output available
on board, except for an oil pump, may be used as the second bilge
pump.
-
(b) The pumps may be fixed or portable and they
should be power driven unless the output of each pump is less than
1.5 tonnes per hour.
-
(c) The output of each pump should in general
meet the following formula:
- where
|
Q |
= |
output in tonnes
per hour and |
|
L |
= |
length of the
craft in metres |
Provided that if, in the case of a particular type of craft,
the Administration is satisfied that having regard to:
-
(i) previous service experience with similar craft;
-
(ii) the conditions of service; and
-
(iii) the constructional features of the craft
a lesser bilge pump output can be permitted, the output
of each bilge pump may be reduced, but in no case to less than:
- where
|
Q |
= |
output in tonnes
per hour with a minimum of 1 tonne per hour |
|
LW |
= |
lightweight of
the craft in tonnes. |
10.6.5 Internal diameters of suction branches
should not be less than 25 millimetres. Suction branches should be
fitted with effective strainers.
10.6.6 Spaces situated above the water level in
the worst anticipated damage conditions may be drained directly overboard
through scuppers fitted with non-return valves.
10.6.7 Any space for which bilge pumping arrangements
are required should be provided with a method of establishing the
presence of water in that space. In unattended machinery spaces this
should be by means of a bilge alarm.