10 April 2025 – ClassNK has issued an approval in principle (AiP) for an Onboard Carbon Capture and Storage system (OCCS) developed by Mitsubishi Shipbuilding. The certification confirms its feasibility from regulatory and safety perspectives.

Right: Mr. Shingen Takeda, Chief Technology Officer, Mitsubishi Shipbuilding
Left: Mr. Masaki Matsunaga, Executive Vice President, ClassNK
Interest in CO2 capture the method from exhaust gases is growing alongside fuel conversion as part of efforts to reduce GHG emissions from ships. In response, the development of OCCS is progressing. To support the smooth development and introduction of related technologies, ClassNK has published the ‘Guidelines for Shipboard CO2 Capture and Storage Systems’ as a subset of the ClassNK Transition Support Services. This guideline outlines safety requirements for OCCS and its installation on ships.
ClassNK reviewed the design of the system based on ‘Guidelines for Shipboard CO2 Capture and Storage Systems’. Upon confirming compliance with the prescribed requirements, ClassNK issues an AiP.
ClassNK will continually strive to contribute to advanced decarbonization initiatives through safety assessments and more.
Approval in Principle (AiP):
At the initial stage of designing or before the specific target ship to be implemented is decided, the design is examined based on the existing regulations such as international conventions and ship classification rules, and an Approval in Principle (AiP) is issued as proof of conformity with requirements. It also prevents rework of regulatory aspects in the post-process, shortens the examination time at the time of class registration, and can be used as a technical basis for external appeal of the design status. For more information, visit our website.