Mitsubishi Shipbuilding Co., Ltd., a part of Mitsubishi Heavy Industries (MHI) Group, has jointly developed a large ammonia carrier that uses ammonia as fuel, in collaboration with Mitsui O.S.K. Lines, Ltd. (MOL) and Namura Shipbuilding Co., Ltd. Approval in Principle (AiP) (Note1) for the design has been obtained from Nippon Kaiji Kyokai (ClassNK). The approval was given through ClassNK’s review of basic design drawings and risk assessment (Hazard Identification Study: HAZID(Note2)) conducted by ClassNK based on the basic design. In order to respond quickly to the future demands, the design have been completed in more detail than generally required for the AiP.

Currently, ammonia is mainly used as a raw material for fertilizer, and its marine transportation volume is limited. In recent years, however, ammonia has gained attention as a clean energy source because it does not emit CO2 during combustion. Its demand is expected to grow as a promising option for achieving carbon neutrality by 2050, particularly for fuel transition in power plants and as a hydrogen carrier.

Mitsubishi Shipbuilding, Mitsui O.S.K. Lines, and Namura Shipbuilding had been working to develop a basic design for a large ammonia carrier, and have now obtained an AiP from ClassNK. The vessel is intended to have an engine that utilizes ammonia as the main fuel source, aiming to reduce greenhouse gas emissions from the vessel itself. Furthermore, the ship is designed to be even larger than conventional Very Large Gas Carrier/Very Large Ammonia Carrier (VLGC/VLAC), enhancing the efficiency of marine transport. This revolutionary ship design satisfies the port entry restrictions at major power plants in Japan and ensures compatibility between ammonia loading/unloading terminals, and cargo handling connections at a level almost equivalent to existing VLGCs.

MHI Group is implementing strategic measures to strengthen its energy transition business. Mitsubishi Shipbuilding plays a key role in this effort, and aims to contribute to the development of the maritime industry in Japan and overseas through maritime engineering technology based on shipbuilding as well as its conventional shipbuilding. Going forward, as a marine system integrator that provides shipbuilding technologies and environmentally friendly products in response to all customer needs, Mitsubishi Shipbuilding will continue to contribute to the further development of maritime logistics and the realization of a decarbonized world.

(1) Approval in Principle (AiP) indicates that a certification body has reviewed the basic design of the subject equipment and confirmed that it meets technical requirements and relevant safety standards. The inspection of the basic design for the ammonia-fueled ammonia carrier was conducted in accordance with ClassNK’s Rules for the Survey and Construction of Steel Ships (Part N Ships Carrying Liquefied Gases in Bulk), and Guidelines for Ships Using Alternative Fuels.
(2) A Hazard Identification Study (HAZID) is a safety evaluation method for plants and systems, which identifies potential risk (hazard) items in a design concept and evaluates the magnitude of the risk and the effectiveness of countermeasures.