To assist Administrations in determining the adequacy of
the design and construction of oil residue (sludge) tanks to facilitate
their cleaning and the discharge of residues to reception facilities,
the following guidance is provided, having effect on ships the keel
of which is laid or which is at a similar stage of construction on
or after 31 December 1990:
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.1 sufficient man-holes should be provided such
that, taking into consideration the internal structure of the oil
residue (sludge) tanks, all parts of the tank can be reached to facilitate
cleaning;
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.2 oil residue (sludge) tanks in ships operating
with heavy oil, that needs to be purified for use, should be fitted
with adequate heating arrangements or other suitable means to facilitate
the pumpability and discharge of the tank content;
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.3 the oil residue (sludge) tank should be provided
with a designated pump for the discharge of the tank content to reception
facilities. The pump should be of a suitable type, capacity and discharge
head, having regard to the characteristics of the liquid being pumped
and the size and position of tank(s) and the overall discharge time.
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.4 where any oil residue (sludge) tank (i.e. oil
residue (sludge) service tankfootnote)
that directly supplies oil residue (sludge) to the means of the disposal
of oil residues (sludge) prescribed in paragraph 3.2 of the Supplement
to IOPP Certificate Form A or B is equipped with suitable means for
drainage, the requirements in subparagraph .3 above may not be applied
to the oil residue (sludge) tank.