16.1 To assist Administrations in determining
the adequate capacity of sludge tanks, the following criteria may
be used as guidance. These criteria should not be construed as determining
the amount of oily residues which will be produced by the machinery
installation in a given period of time. The capacity of sludge tanks
may, however, be calculated upon any other reasonable assumptions.
For a ship the keel of which is laid or which is at a similar stage
of construction on or after 31 December 1990, the guidance given in
items .4 and .5 below should be used in lieu of the guidance contained
in items .1 and .2.
-
.1 For ships which do not carry ballast water
in oil fuel tanks, the minimum sludge tank capacity (V
1) should be calculated by the following formula:
- where
|
K
1
|
= |
0.01 for ships where heavy fuel oil is purified for main engine
use, or 0.005 for ships using diesel oil or heavy fuel oil which does
not require purification before use, |
|
C
|
= |
daily
fuel oil consumption (tonnes); and |
|
D
|
= |
maximum
period of voyage between ports where sludge can be discharged ashore
(days). In the absence of precise data a figure of 30 days should
be used. |
-
.2 When such ships are fitted with homogenizers,
sludge incinerators or other recognized means on board for the control
of sludge, the minimum sludge tank capacity (V
1)
should, in lieu of the above, be:
|
V
1
|
= |
1 m3 for ships of 400 gross tonnage and above but
less than 4,000 gross tonnage, or 2 m3 for ships of 4,000
gross tonnage and above.
|
-
.3 For ships which carry ballast water in fuel
oil tanks, the minimum sludge tank capacity (V
2)
should be calculated by the following formula:
- where
|
V
1
|
= |
sludge tank capacity specified in .1 or .2 above in m3,
|
|
K
2
|
= |
0.01 for heavy fuel oil bunker tanks, or 0.005 for diesel oil
bunker tanks, and |
|
B
|
= |
capacity
of water ballast tanks which can also be used to carry oil fuel (tonnes). |
-
.4 For ships which do not carry ballast water
in fuel oil tanks, the minimum sludge tank capacity (V
1) should be calculated by the following formula:
- where
|
K
1
|
= |
0.015 for ships where heavy fuel oil is purified for main engine
use or 0.005 for ships using diesel oil or heavy fuel oil which does
not require purification before use, |
|
C
|
= |
daily
fuel oil consumption (m3); and
|
|
D
|
= |
maximum
period of voyage between ports where sludge can be discharged ashore
(days). In the absence of precise data a figure of 30 days should
be used. |
-
.5 For ships where the building contract is placed,
or in the absence of a building contract, the keel of which is laid
before 1 July 2010, and which are fitted with homogenizers, sludge
incinerators or other recognized means on board for the control of
sludge, the minimum sludge tank capacity should be:
-
.5.1 50% of the value calculated according to
item .4 above; or
-
.5.2 1 m3 for ships of 400 gross tonnage
and above but less than 4,000 gross tonnage or 2 m3 for
ships of 4,000 gross tonnage and above; whichever is the greater.
16.2 Administrations should establish that in
a ship the keel of which is laid or which is at a similar stage of
construction on or after 31 December 1990, adequate tank capacity,
which may include the sludge tank(s) referred to under 16.1 above,
is available also for leakage, drain and waste oils from the machinery
installations. In existing installations this should be taken into
consideration as far as reasonable and practicable.