Effect of ship size on EEDI requirements for large container ships

The Energy Efficiency Design Index (EEDI) is a technical measure introduced by International Maritime Organization (IMO) aiming to improve energy efficiency of ships. The Attained EEDI of a ship has to be calculated for every new ship and lower than the Required EEDI determined by the EEDI reference line, which represents world fleet average for a certain ship type, and an appropriate reduction factor. Nowadays ultra large container ships (ULCS) are being built, and for the time being they are not accounted for in the Required EEDI formulation for container ships. Consequently, in most cases, it makes existing EEDI criteria relatively irrelevant for the design of ULCS. In this paper, the effect of ship size on the EEDI requirements for large container ships is elaborated in details. Several important issues are addressed: updating of existing baseline formulation with new ULCS data available in the IHS Fairplay database; extending the EEDI reference line into the EEDI reference surface for container ships as a function of ship capacity and speed; establishing a relation between the deadweight used in the EEDI calculation and the real ship capacity measured in TEU which enables more practical data handling in overall container ship design procedure.