This study analyses the development of the EIVs* of new ships built over the last 50 years. The analysis shows that after a period of deteriorating or constantly poor EIVs in the 1970s, design efficiency improved considerably for all ship types and all size categories in the 1980s, reaching an optimum in the 1990s. In the 2000s, EIVs deteriorated again.
This historical analysis suggests there were major improvements in design efficiency within the relatively short space of a decade: during the 1980s, EIVs improved by 22-28% depending on ship type and size. This development seems to have been purely market-driven, principally through a combination of sharply increasing fuel prices and constant or low freight rates.
An analysis of the factors contributing to EIV improvements in the 1980s shows that in some, but not all cases, efficiency improvements were brought about by reductions in design speed, while in other cases vessel size increased. However, these two developments cannot fully explain the improvements; in many cases, the evidence points to improvements in hull design and propulsion efficiency having also contributed significantly. Likewise, the deterioration in EIVs after the 1990s appears to be due, at least in part, to designs in which cargo capacity or capital costs were given more weight than fuel efficiency.
* EIV (Estimated Index Value, a simplified form of EEDI, Energy Efficiency Design Index).