1 It should be documented that chapter
12, paragraph 2.2.1.3, of the Code is satisfied and the suction
inlet is fully submerged under all conditions given in this unified
interpretation.
1.1 Operational seagoing condition for which roll,
pitch and heave should be taken into account.
The lightest seagoing condition should be considered, which
is defined as the ballast condition which gives shallowest draught
at the position of the sea chest and emergency fire pump as given
in the approved stability booklet (or preliminary stability calculation
for new building). The following table should be applied for the calculation
of roll, pitch and heave. The heave combined pitch and heave combined
roll are taken into account separately.
1.1.1 Heave combined pitchfootnote in head sea
L, m
|
75 and below
|
100
|
125
|
150
|
175
|
200
|
225
|
250
|
300
|
350 and above
|
φ, deg
|
4.5
|
4
|
3.2
|
2.7
|
2.3
|
2.1
|
1.8
|
1.7
|
1.6
|
1.5
|
H, m
|
0.73
|
0.8
|
0.87
|
0.93
|
0.98
|
1.03
|
1.07
|
1.11
|
1.1.9
|
1.25
|
|
|
|
|
|
|
|
|
|
|
|
|
Note
|
Values at the intermediate length of ships are to be obtained by
linear interpolation.
|
|
where:
|
|
|
L:
|
length of the ship, in metres, as defined in the International
Convention on Load Lines in force, or length between perpendiculars at the
ballast draught, whichever is greater
|
|
φ
|
pitch anglefootnote as defined in figure 1
|
|
H:
|
heave amplitude as defined in figure 1.
|
1.1.2 Heave combined roll in beam sea
Heave combined roll anglefootnoteshould
be taken as:
1.2 The emergency fire pump suction should be
submerged at the waterlines corresponding to the two following conditions:
-
.1 a static waterline drawn through the level
of 2/3 immersion of the propeller at even keel (for pod or thruster
driven ship, special consideration should be given); and
-
.2 the ship in the arrival ballast condition,
as per the approved trim and stability booklet, without cargo and
with 10% stores and fuel remaining.
For either condition, roll, pitch and heave need not be
applied.
1.3 A ship operating solely in sheltered water
issued with SOLAS Certificates should be subject to compliance with
the still water submergence requirements set out in paragraph 1.2.1
above.
2 In all cases the net positive suction head (NPSH)
available for the pump should be greater than the NPSH required.
3 Upon completion of the emergency fire pump installation,
a performance test confirming the pump's capacity required in the
FSS Code, chapter 12, paragraph 2.2.1.1,
should be carried out and, if the emergency fire pump is the main
supply of water for any fixed fire-extinguishing system provided to
protect the space where the main fire pumps are located, the pump
should have the capacity for this system. As far as practicable, the
test should be carried out at the draught corresponding to the lightest
seagoing condition.