Appendix II – Test Cycles and Weighting Factors (Regulation 13)
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Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.328(76) - Amendments to the Annex of the Protocol Of 1997 to Amend the International Convention for the Prevention of Pollution from Ships, 1973, As Modified by the Protocol of 1978 Relating Thereto - (adopted on 17 June 2021) - Annex - MARPOL Annex VI Regulations for the Prevention of Air Pollution from Ships - Appendix II – Test Cycles and Weighting Factors (Regulation 13)

Appendix II – Test Cycles and Weighting Factors (Regulation 13)

 The following test cycles and weighting factors shall be applied for verification of compliance of marine diesel engines with the applicable NOx limit in accordance with regulation 13 of this Annex using the test procedure and calculation method as specified in the revised NOX Technical Code 2008.

  • .1 For constant-speed marine engines for ship main propulsion, including diesel-electric drive, test cycle E2 shall be applied;

  • .2 For controllable-pitch propeller sets test cycle E2 shall be applied;

  • .3 For propeller-law-operated main and propeller-law-operated auxiliary engines the test cycle E3 shall be applied;

  • .4 For constant-speed auxiliary engines test cycle D2 shall be applied; and

  • .5 For variable-speed, variable-load auxiliary engines, not included above, test cycle C1 shall be applied.

 Test cycle for constant speed main propulsion application
(including diesel-electric drive and all controllable-pitch propeller installations)

Test cycle type E2 Speed 100% 100% 100% 100%
Power 100% 75% 50% 25%
Weighting factor 0.2 0.5 0.15 0.15

 Test cycle for propeller-law-operated main and propeller-law-operated auxiliary engine application

Test cycle type E3 Speed 100% 91% 80% 63%
Power 100% 75% 50% 25%
Weighting factor 0.2 0.5 0.15 0.15

 Test cycle for constant-speed auxiliary engine application

Test cycle type D2 Speed 100% 100% 100% 100% 100%
Power 100% 75% 50% 25% 10%
Weighting factor 0.05 0.25 0.3 0.3 0.1

 Test cycle for variable-speed and -load auxiliary engine application

Test cycle type C1 Speed Rated Intermediate Idle
Torque 100% 75% 50% 10% 100% 75% 50% 0%
Weighting factor 0.15 0.15 0.15 0.1 0.1 0.1 0.1 0.15

 In the case of an engine to be certified in accordance with paragraph 5.1.1 of regulation 13, the specific emission at each individual mode point shall not exceed the applicable NOx emission limit value by more than 50% except as follows:

  • .1 The 10% mode point in the D2 test cycle.

  • .2 The 10% mode point in the C1 test cycle.

  • .3 The idle mode point in the C1 test cycle.

Parent topic: Annex - MARPOL Annex VI Regulations for the Prevention of Air Pollution from Ships
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