In order to meet the energy efficiency requirement (i.e. the ‘required EEXI’), that is introduced in the revised MARPOL Annex VI regulations, ships may be required to undertake certain modifications to improve their calculated efficiency (i.e. the ‘attained EEXI’).
This TAN aims to give guidance on common queries relating to these methods when used on an Isle of Man ship.
One option to improve a ship’s attained EEXI is a shaft power limitation (‘ShaPoLi’).
There are two standards to which ShaPoLi systems may comply with to be accepted for use for Isle of Man ships:
MEPC.335(76) - 2021 Guidelines on the Shaft / Engine Power Limitation System to Comply with the EEXI Requirements and Use of a Power Reserve; or
IACS Unified Requirement No 172 - EEXI Implementation Guidelines.
Any power limitation which is installed prior to the first periodical survey after 1st January 2023 does not need to be switched on until the survey is completed.
Vessels with ShaPoLi systems will require two sets of maneuvering charts and posters, showing data for the vessel with the limitation in place and with it overridden and reserve power in use.
In all cases, Bridge teams should not hesitate to use the reserve power where necessary to ensure the safety of the ship and its crew.