Modification of the EEDI for Ro-ro Passenger Ships

Abstract

In the 3rd IMO GHG study the new data on the ships emissions indicate a clear need for improvements in ship energy efficiency in order to preserve the environment. Although the majority of the pollution originates from the international shipping, the environmental impact of the short-sea shipping, primarily from ro-ro passenger ships, should not be neglected. The pollution originating from these ships is especially pernicious for public health since they operate in and near ports and highly populated areas. The newest amendments to MARPOL Annex VI introduce the Energy Efficiency Design Index (EEDI). The EEDI should be a measure of ships energy efficiency, but its application is limited since it may not be applied to ships with diesel-electric or hybrid propulsion systems. Also the EEDI seems not to be feasible for the regulation of energy efficiency for ro-ro passenger ships because their design criteria vary too much. The aim of this paper is to propose a new approach to the EEDI definition for ro-ro passenger ships. It introduces the Reference surface as the function of ships capacity and speed instead of the Reference line. It also expands the attained EEDI calculation to different loads trying to give a clearer view of the ships CO2 emission. This modified EEDI would then allow a fair comparison between different ro-ro passenger ships.