Panagiotis Leontis, Managing Director at Intership Maritime Inc., FRINA CEng, Chairman of Hellenic Joint Branch (IMarEST and RINA) and Chairman of Hellenic Marine Technical Consultants & Surveyors Association, discusses technical and economic considerations for propeller modifications.

The entry into force of the Energy Efficiency Existing Ship Index (EEXI) in November 2022 has led to a considerable reduction in power, in many cases exceeding 25%. This measure has resulted in a noticeable decrease in propeller efficiency, as propellers are called upon to abide at a rating often as much as 30-40% less than the original MCR, for which they were designed.

Consequently, the propeller, which was optimised for the old design MCR/RPM/ship-speed before EEXI is now not able to compensate for the new operational difference as effectively as before, resulting in reduced efficiency and fuel wastage. There are a variety of factors ultimately affecting a vessel’s performance and the efficiency of its fuel consumption.