Nitrogen Oxides (NOx) Regulation 13.7; Marpol Annex VI; Pre-2000 Engines.

IMO at the 58Th session of the MEPC adopted MEPC 176(58) and introduce in 2008 Annex VI amendments, The revised MARPOL ANNEX VI become in to force on 01/07/2010, and under this amendments Tier I standards become applicable to existing engines installed on ships built between 1st January 1990 to 31st December 1999, with a displacement ≥ 90 litre per cylinder and rated output ≥ 5000 kW, subject to availability of approved engine upgrade kit. Before commonly known, as NOx control on Pre-2000 engines.


This NOx control on Pre-2000 engines will generally affect only the main engines on such ships, the 90 litre/cylinder criteria represents, for example in current medium speed engine designs, engines with a bore of 460 mm and above.

The amendments require on these engines: Either the installation of a certified “Approved Method”, not necessarily approved by the ship’s flag State but for any other administration on behalf of IMO that has certified an “Approved Method” which results in an emission value no higher than the relevant Tier I level for that particular engine model, rating and duty or the engine has been certified that operates within the limits set forth Tier I, II or III.

If compliance is demonstrated through The Approved Method, it must be applied no later than the first renewal survey which occurs more than 12 months after deposition of the advice to IMO.


However, if the ship owner can demonstrate that the Approved Method is not commercially available, by vessel’s flag administration confirmation, at that time then it is to be installed no later than the next annual survey after which it has become available. Given within regulation 13.7 are constraints on the Approved Method that limit its cost and detrimental effects on engine power and fuel consumption.

An approved Method shall include an approved Method File which accompanied the engine during its all life and where is stated the engine on board verification to confirm compliance during successive surveys.

Implementation of MARPOL VI, regulation 13.7 must be achieved by following the next steps:


• Ship constructed between 01/01/1990 and 31/12/2000 and the engine power > 5000 Kw and   displacement > 90 litres per cylinder?
No, no further action required.
Yes, engines details shall be added to the supplement attach to IAPP Certificate.

• Engine has been certified as being Tier I, II or II?
Yes, details to be added to the supplement. Engine in compliance with Reg. 13.7
No, below alternatives are possible.

• Engine has an Approved Method (A.M.) available?
No, no further actions required.
Yes, below alternatives are possible. However, Supplement must be updated as A.M. exists.

• Is vessel at first renewal survey, which occurs 12 month or more after notification to IMO and it was installed?
Yes, add to supplement that A.M. exists & A.M. Installed. Now vessel is in compliance with Reg. 13.7
No, below alternative is possible

• Is the vessel at next Annual Survey and Flag confirmed that the A.M. is not commercially available?
Yes, add to supplement that A.M. exists & A.M. no commercially available.
No, Flag shall be contacted and certificates withdraw “no in compliance”.