Development of an emission assessment scheme for a fishing vessel diesel propulsion engine

Abstract

While a significant effort has been made to reduce marine diesel exhaust emissions, there is a need to examine the world fleets and assess the current levels of engine emissions. This paper introduces an emission assessment scheme that the authors have applied to analyse the US fishing fleet with length L>22.9 m. The present results give an estimate that the 1051 vessels in the US fishing fleet produce 306 tonnes/day of nitrous oxides (NO _x ). The largest power values are found in the decades of 1960 to 1980. The actual power (kW) is compared with a reference power (kW_o) using the powering index ratio (PIR = kW/kW_o). It was found that 50–80 per cent of the power in seiners, trawlers, and crabber/trapper/clam vessels have a PIR>2.5. Based on this assessment, it is clear that a large number of trawlers and seiners are overpowered – resulting in high diesel engine NO _x emissions.