INTERNATIONAL MARITIME ORGANIZATION
MARINE ENVIRONMENT PROTECTION
COMMITTEE
44th session
Agenda item 11
MEPC 44/11/7
24 December 1999
Original: ENGLISH
PREVENTION OF AIR POLLUTION FROM SHIPS
Revision of the NOx Technical Code
Tiers 2 emission limits for diesel marine engines at or above 130 kW
Submitted by the United States
SUMMARY
Executive summary:
This paper outlines the views of the United States on the need for establishing a second tier of emission limits for marine diesel engines above 130 kW.
Action to be taken: Paragraph 16
Related documents: MP/CONF.3/35
Background
1 On September 26, 1997, the Parties to the International Convention for the Prevention of Pollution from Ships, 1973, as Modified by the Protocol of 1978 Relating Thereto (MARPOL 73/78) adopted a new Annex VI to the Convention, Regulations for the Prevention of Air Pollution from Ships (1997 Protocol). Regulation 13 of the 1997 Protocol sets out emission limits for emissions of nitrogen oxides (NOx) from marine diesel engines. According to Regulation 13, the NOx emissions of any diesel engine with a power output of more than 130 kW installed on a ship constructed on or after 1 January 2000, or that undergoes a major conversion on or after that date, cannot exceed the following limits: **
(i) 17.0g/kWh
when n is less than 130 rpm
(ii) 45.0*n(-0.2) g/kWh
when n is 130 or more but less than 2000 rpm
(iii) 9.8 g/kWh
when n is 2000 rpm or more
where n｡疵ated engine speed (crankshaft revolutions per minute).
**See Figure 1. at the annex of this paper for a graphical representation of this engine speed (rpm) to NOx emissions relationship.
