Mitsui O.S.K. Lines- Namura Shipbuilding and Mitsubishi Shipbuilding Secure AiP for Large Ammonia-Fuelled Carrier
Mitsui O.S.K. Lines (MOL), Namura Shipbuilding, and Mitsubishi Shipbuilding have received Approval in Principle (AiP) from ClassNK for their jointly developed large ammonia-fuelled ammonia carrier. The milestone marks a significant step in the maritime industry’s shift toward sustainable fuel alternatives.
A Milestone in Sustainable Shipping
On March 14, 2025, the three companies announced their success in obtaining AiP from ClassNK (Nippon Kaiji Kyokai) for their newly designed ammonia-fuelled ammonia carrier. This vessel is designed to use ammonia as its primary fuel, aligning with global efforts to reduce greenhouse gas (GHG) emissions in the maritime sector. Compared to conventional Very Large Gas Carriers (VLGCs) and Very Large Ammonia Carriers (VLACs), the new ship is significantly larger, improving transport efficiency and meeting the anticipated rise in ammonia transportation demand.
The collaboration among Mitsui O.S.K. Lines, Namura Shipbuilding, and Mitsubishi Shipbuilding reflects the industry’s commitment to reducing the environmental impact of maritime operations. The companies have been working together on the development of this large ammonia-fuelled carrier since 2021, envisioning ammonia as a crucial zero-carbon fuel and hydrogen carrier.
A Strategic Approach to Ammonia-Powered Vessels
Ammonia has gained traction as a next-generation marine fuel due to its potential to significantly cut CO2 emissions. As industries worldwide focus on decarbonization, ammonia is seen as an essential alternative to conventional fossil fuels, particularly in sectors that are difficult to electrify. The newly developed ammonia-fuelled vessel is positioned to support the expansion of ammonia as a fuel, as well as its use in power generation via ammonia co-firing in power plants.
A key aspect of the design is its increased cargo capacity. By exceeding the size of existing VLGCs and VLACs, the ship ensures higher efficiency in transporting ammonia, which is expected to experience growing demand in the coming decades. Furthermore, the vessel is designed to meet port entry restrictions for major power plants in Japan, a critical factor in ensuring its operational feasibility.
ClassNK’s Approval Process and Safety Measures
ClassNK played a crucial role in evaluating the vessel’s design, focusing on safety, efficiency, and environmental compliance. As part of the AiP review, ClassNK conducted a Hazard Identification (HAZID) assessment, prioritizing safety concerns associated with ammonia toxicity. The HAZID assessment ensured that necessary countermeasures were incorporated into the ship’s design to mitigate risks related to ammonia handling.
Ensuring compatibility with existing infrastructure was another priority. The vessel’s cargo manifolds and other ship-to-shore interfaces were carefully designed to maintain operational efficiency comparable to traditional VLGCs. This design consideration facilitates the seamless integration of the new vessel into current ammonia supply chains without requiring extensive modifications to existing port facilities.
Advancing the Design Beyond AiP Requirements
While securing AiP is a major achievement, the three companies have taken the vessel’s development further than the standard requirements for this stage. The ship’s design is more advanced than typical AiP-acquired projects, positioning it for swift adaptation to market demands and potential commercialization.
By proactively addressing regulatory and technical challenges, Mitsui O.S.K. Lines, Namura Shipbuilding, and Mitsubishi Shipbuilding have accelerated the pathway to deployment for ammonia-fuelled carriers. This strategic approach aims to ensure that the vessel can be rapidly introduced into commercial operation as ammonia adoption expands.
Ammonia as a Key to Carbon-Neutral Shipping
The global shipping industry is under increasing pressure to reduce emissions, with the International Maritime Organization (IMO) setting ambitious targets for GHG reduction. Ammonia is considered one of the most promising solutions, as it does not emit CO2 when burned in engines designed for its use. However, challenges remain, including ammonia’s toxicity and the need for new bunkering and handling infrastructure.
With the newly approved ammonia-fuelled vessel, Mitsui O.S.K. Lines, Namura Shipbuilding, and Mitsubishi Shipbuilding are taking a proactive stance in tackling these challenges. The project also aligns with Japan’s broader strategy to establish itself as a leader in ammonia fuel technology and logistics.
Future Prospects and Industry Implications
The approval of this large ammonia-fuelled carrier is expected to have significant implications for the shipping industry and ammonia supply chains. As more industries and countries invest in ammonia-based energy solutions, the demand for efficient transport solutions will increase.
By developing an ammonia-fuelled ship that is both larger and safer, the three companies are setting a new benchmark for future vessels in the sector. This initiative not only advances shipping decarbonization efforts but also strengthens Japan’s position in the global ammonia value chain.
Looking ahead, Mitsui O.S.K. Lines, Namura Shipbuilding, and Mitsubishi Shipbuilding plan to further refine the vessel’s design, conduct prototype testing, and work toward full-scale commercialization. The companies remain committed to contributing to a greener maritime industry by leading the way in ammonia-fuelled ship development.
The Approval in Principle (AiP) granted by ClassNK marks a key milestone in the shift towards sustainable shipping solutions. With its enhanced cargo capacity, reduced emissions, and compliance with safety and operational standards, the new ammonia-fuelled ammonia carrier represents a major step forward in achieving a carbon-neutral maritime industry.
As the global push for greener fuels intensifies, innovations like this will play a crucial role in defining the future of maritime transport. Mitsui O.S.K. Lines, Namura Shipbuilding, and Mitsubishi Shipbuilding have demonstrated a strong commitment to sustainability, and their jointly developed vessel stands as a testament to the industry’s evolving efforts to embrace cleaner, more efficient technologies.
