New definition of "Sludge Tank" and amended Oil Record Book Codes according with Marpol Annex I as from 1 January 2011.

As from 1 January 2011 a new definition of "Sludge Tank" is applicable to vessels with Marpol Annex I (IOPP) certificate. Also the codes for Oil Record Book has been amended. Ch. Engineers should use new codes in their ORB entries in order to avoid problems with PSC. In this post we have prepared a comparison between old and new Oil Record Book codes for your easy reference, describing the requirements. You can download highlighted MEPC187(59).

Description of requirement

MEPC.187(59) amended Marpol Annex I that will enter in to force 1 January 2011. It gives a new definition of sludge tank as follows:

30.31 Oil residue (sludge) means the residual waste oil products generated during the
normal operation of a ship such as those resulting from the purification of fuel or
lubricating oil for main or auxiliary machinery, separated waste oil from oil
filtering equipment, waste oil collected in drip trays, and waste hydraulic and
lubricating oils.


30.32 Oil residue (sludge) tank means a tank which holds oil residue (sludge) from
which sludge may be disposed directly
through the standard discharge connection
or any
other approved means of disposal.

According with the new definition, tanks that are NOT directly connected to approved means of discharge (shore connection) are NOT considered as “Sludge Tanks”. So holding tanks which used to retain sludges prior to incineration and are not connected to approved discharge can NOT be considered as “Sludge Tanks”.

Also Oil Record Book Codes have been amended. Ch. Engineers must pay particular attention to code (C) 11 that has been redefined. For your easy reference we have prepared a comparison between NEW and OLD oil record book codes.

In next annual/ intermediate/ renewal survey class should issue new IOPP supplement with corrected sludge tanks.

Finally MEPC 187(59) gives definition of bilge water and bilge water holding tanks. But these changes does not affect existing certificates or practices.

How We Can Help

- Download comparison of OLD Marpol 2010 vs NEW Oil Record Book Codes Marpol 2011. Amended comparison.
- Download MEPC.187(59) marked with most important changes.
-Download IMO Guidance for the recording of operations in the Oil Record Book MEPC.1/Circ.736