As already advised in ClassNK Technical Information No.TEC-0771 dated 13 May 2009, marine diesel engines with a power output of more than 5,000kW and a per cylinder displacement at or above 90 liters installed onboard ships constructed on or after 1 January 1990 but prior to 1 January 2000 are to comply with Tier I emission limits using an Approved Method, provided that an Approved Method for that engine has been certified by an Administration (Reg. 13.7.1 of ANNEX VI). In the case of the diesel engines described below, the Administration of Denmark has recently certified methods for reducing the NOx emission levels of each respective diesel engine as Approved Methods.

Since the IMO has subsequently newly published relevant information on the Approved Methods for MAN B&W S70MC and S50MC engines in MEPC Circulars, as attached, this ClassNK Technical Information provides the relevant information on these methods and their confirmation during survey, as described below.

1. Notification about the Approved Method for MAN B&W S70MC type engines
(1) Notification of additional information(MEPC.1/Circ.738/Add.1)
On 10 August 2011, the IMO published additional information in MEPC.1/Circ.738/Add.1 (Attachment 1), regarding the Approved Method for MAN B&W S70MC engines shown in the table below, which was already advised in ClassNK Technical Information No.TEC-0836 dated 1 December 2010. This MEPC Circular contains additional information about the conditions to identify those diesel engines to which the Approved Method is to be applied (fuel nozzle type and shop test performance value) and a sample of the Approved Method File, etc.