ClassNK has released a revised edition of its Guidelines for Ships Using Alternative Fuels.
Edition 3.1 updates safety requirements for ships using hydrogen, methanol and ethanol as fuel.
The changes aim to help shipyards, designers and shipowners develop alternative-fueled vessels in line with the latest international standards.
New requirements for hydrogen-fueled ships
ClassNK has carried out a full revision of Part D, which covers hydrogen-fueled ships.
The classification society incorporated the IMO’s Interim Guidelines for the Safety of Ships Using Hydrogen as Fuel (MSC.1/Circ.1701).
ClassNK also added estimated hydrogen leak frequencies to the guidelines.
The estimates use a Bayesian method and appear in Appendix 2 of Part D. According to ClassNK, they can support safety assessments required for administration approval of alternative-fueled ships.
ClassNK participated in the development of the IMO hydrogen guidelines as part of the Japanese delegation to IMO’s Sub-Committee on Carriage of Cargoes and Containers (CCC 11).
Methanol and ethanol requirements expanded
ClassNK has also revised Part A of the guidelines.
The new edition introduces structural strength requirements for methanol and ethanol fuel tanks.
ClassNK developed these requirements based on its experience reviewing the design of such vessels.
The classification society noted that specific structural strength requirements for these tanks are not included in the IMO guidelines for ships using methanol and ethanol as fuel, MSC.1/Circ.1621.
According to ClassNK, the additional requirements should make fuel tank design assessments more efficient.
Supporting alternative-fueled ship development
ClassNK’s guidelines cover ships using methanol, ethanol, LPG, ammonia and hydrogen.
They include requirements for equipment, controls and safety devices. These measures aim to address risks to ships, seafarers and the environment.
ClassNK said it will continue developing standards and certification services to support the maritime industry’s environmental efforts.
The revised guidelines are available through the My Page section of the ClassNK website.
