Regulation 13 sets progressively reducing NOx emission limits for diesel engines (other than emergency engines) of over 130 kW output power in three tiers (Tier I, Tier II and Tier III), according to date of construction of the ship, with the lowest limits applied to engines in ships built on or after 1 January 2016 when operating in an Emission Control Area. Within each tier the NOx emission limit (in grams per kilowatt-hour, or g/kWh) is set according to the rated engine speed (i. e. crankshaft revolutions per minute).
How does the revised MARPOL Annex VI regulate emissions of nitrogen oxides?
