‘World-first’ as ammonia-fuelled two-stroke engine passes quality assurance

February 25th, 2026

Swiss marine power company WinGD has completed what it says is the world’s first type approval (TAT) and factory acceptance testing (FAT) for an ammonia-fuelled two-stroke marine engine.

Source: WinGD

Both TAT and FAT programs were completed last month, with testing of the X52DF-A-1.0 engine carried out at the HD Hyundai Heavy Industries’ Engine & Machinery (HHI-EMD) facility in South Korea, witnessed by classification society Lloyd’s Register (LR), with representatives from all major classification societies, supervised by Belgian shipping company EXMAR.

The testing was carried out on a 52-bore engine to be installed on a 46,000m3 LPG/ammonia carrier on order for EXMAR. According to WinGD, the vessels in the series are set to become the first ammonia-fuelled gas carriers to enter commercial service.

“These successful tests represent a key milestone in EXMAR’s development of ammonia as a marine fuel, a journey that began in 2021. Drawing on more than 40 years of experience in transporting ammonia as cargo, EXMAR has been able to critically assess both the engine design and the test program, with particular attention to the safety considerations associated with using a toxic cargo as fuel,” said Kristof Coppé, Director Fleet Operations & Technical Business Development at EXMAR.

“EXMAR now looks ahead to the next phase, which will involve sea trials on ammonia fuel. These trials will have to validate the seamless integration and performance of all onboard systems. Preparations are currently underway, with the trials scheduled to take place in the coming months.”

WinGD noted that excellent performance has been demonstrated throughout a rigorous multi-year development and testing process, with emissions data from the X‑DF‑A engine impressing with NOx emissions during ammonia operation well below those generated during diesel use. Excellent results have also been recorded for emissions of N2O.

The Swiss firm has also revealed that it had secured an early orderbook of around 30 X-DF-A engines across multiple vessel segments, including gas and bulk carriers, tankers and container vessels.

“Completing Type Approval Testing and Factory Acceptance Testing with our joint development partner HHI-EMD represents a major technical milestone in the development of ammonia-fuelled two-stroke propulsion. As first movers, we are addressing a completely new fuel landscape, where safety, control and system integration are paramount. We have developed an engine that has been well proven to be safe and efficient by tackling, one by one, all the technical challenges we faced,” said Sotiris Topaloglou, Global Head of Testing & Validation at WinGD.

“Demonstrating the world’s first TAT for an ammonia-fuelled two-stroke engine with strong results demonstrates that ammonia propulsion can meet the highest standards of reliability, performance and safety expected by the industry for commercial marine application.”