Mitsubishi Shipbuilding Acquires Certification from WinGD for MAmmoSS® Ammonia Fuel Handling System
-- First Such Certification in Japan, Advancing Commercial Deployment of Ammonia-Fueled Vessels --

Certificate Presentation Ceremony

Tokyo, November 9, 2026 - Mitsubishi Shipbuilding Co., Ltd., a part of Mitsubishi Heavy Industries (MHI) Group, has obtained Supplier Pre-Approval from WinGD, the Swiss marine large engine licensor, for the MAmmoSS® ammonia fuel handling system.(Note1) This is the first time a Japanese company has acquired Supplier Pre-Approval, achieved through collaboration between Mitsubishi Shipbuilding and WinGD based on a Memorandum of Understanding (MoU) signed in 2023 and the successful completion of a basic design for an ammonia fuel supply system in 2024.

The equipment subject to Supplier Pre-Approval is the Fuel Valve Unit (FVU)(Note2) and Ammonia Injector Cooling Water System (AICWS),(Note3) essential components for the X-DF-A engine, an ammonia-fueled large, low-speed two-stroke marine engine developed and marketed by WinGD. Technical consultations with WinGD confirmed the development, design, and manufacturing capabilities of Mitsubishi Shipbuilding, as well as its quality assurance system and project execution capabilities, leading to the acquisition of the Supplier Pre-Approval. Going forward, Mitsubishi Shipbuilding will pursue the market launch for the FVU and AICWS.

MAmmoSS consists of a "core package" for general use regardless of the engine licensor, and a "customization package" to optimize the system for each licensor. The FVU and AICWS subject to this certification are classified as a customization package for the X-DF-A engine. FVU and AICWS units are usually controlled separately by controllers installed on each device, but integration with the MAmmoSS core package allows for integrated control through a central control unit. This also contributes to operational efficiency and easier maintenance.

Because ammonia emits no CO₂ when burned, it is considered a promising next-generation fuel option for achieving decarbonization in international marine transport. The world's first ocean-going ammonia-fueled vessel is already in service, and with several additional vessels scheduled to enter service this year, the technology is reaching the practical use stage. Mitsubishi Shipbuilding combines the core and customization packages of MAmmoSS to build optimal systems for onboard equipment such as multiple ammonia-fired engines and boilers. This provides shipping companies, shipyards, and other customers with convenience and safety.

MHI Group is implementing strategic measures to strengthen its energy transition business. Mitsubishi Shipbuilding plays a key role in this effort, and by providing safe and efficient ammonia fuel utilization systems for ships, will contribute to the decarbonization of the maritime industry and the realization of a carbon-neutral society.

Commenting on the acquisition of the Supplier Pre-Approval, Shin Ueda, President of Mitsubishi Shipbuilding, said: "This approval is the result of joint development and technical consultations with WinGD for ammonia fuel-related technologies, and marks a significant step toward the widespread adoption of ammonia-fueled vessels. Mitsubishi Shipbuilding will continue to contribute to the decarbonization of the maritime industry through the development and supply of ammonia fuel supply systems and related equipment."

Benny Hilström, Executive Vice President of WinGD said: "Our high regard for Mitsubishi Shipbuilding's technological capabilities and quality management system led to the awarding of this Supplier Pre-Approval. We will continue to deepen our cooperative relationship, and work to develop the market for ammonia-fueled marine vessels."

• 1The Mitsubishi Ammonia Supply and Safety System (MAmmoSS®) consists of an Ammonia Fuel Supply System (AFSS) and an Ammonia Gas Abatement System (AGAS), along with control equipment to integrate and regulate these systems. The AFSS, AGAS, and central control unit are classified as the "core package" of MAmmoSS. "MAmmoSS" is a registered trademark of Mitsubishi Shipbuilding in Japan and other countries.
• 2The FVU (Fuel Valve Unit) is a valve module to supply and shut off fuel to the engine. It uses inert gas to safely remove residual ammonia from the lines, and helps to circulate the ammonia solution from the AICWS.
• 3The AICWS (Ammonia Injector Cooling Water System) circulates the ammonia solution via the FVU, neutralizes and removes ammonia remaining in the lines, and cools the fuel injection valve during oil-fueled operation.