Japanese classification society ClassNK has released Edition 3.0.1 of its Part A Guidelines for Ships Using Alternative Fuels, adding supplementary explanations on safety requirements for methyl and ethyl alcohol-fuelled ships.

The updated guidelines include clarifications on frequently requested requirements and compile key points on required plans, documents, and class survey items for vessels using methanol and ethanol as fuel.

According to ClassNK, the revision responds to an increasing number of methyl alcohol-fuelled ships being built both domestically and internationally. The society said it has issued the revised edition to clarify requirements in Part A and to support stakeholders involved in such projects.

The Guidelines for Ships Using Alternative Fuels describe safety requirements for alternative-fuelled ships, stipulating requirements for installation, controls, and safety devices to minimize risks to ships, seafarers, and the environment posed by the use of alternative fuels. The guidelines consist of four parts covering methyl/ethyl alcohol (Part A), LPG (Part B), ammonia (Part C), and hydrogen (Part D).

Edition 3.0.1 adds supplementary explanations for design topics that have attracted attention in shipbuilding, utilizing knowledge and experience gained from design review activities and further clarifying the interpretation of safety requirements for methyl and ethyl alcohol-fuelled ships.

ClassNK noted that discussions on the revision of the IMO Interim Guidelines — MSC.1/Circ.1621, which form the basis of Part A — are scheduled to take place at the 12th session of the IMO Sub-Committee on Carriage of Cargoes and Containers (CCC 12) in September 2026. The classification society said it will monitor these discussions and reflect the outcomes in Part A as necessary.

The guidelines are part of ClassNK's Transition Support Services, which the society describes as supporting customers' transition to zero-emission shipping through the provision of safety requirements and guidance for design.

The guidelines are available to download via the 'Guidelines' section of My Page on ClassNK's website after registration.