Lloyd’s Register approval in principle will support shipowner confidence on vessel designs using ammonia-fuelled main engines.

Swiss marine power company WinGD has secured the first ever approval in principle for two­­‑stroke engines fuelled with ammonia. Lloyd’s Register awarded the AiP to WinGD’s X-DF-A dual-fuel range, giving shipowners the assurances they need to realise vessel designs using ammonia-fuelled main engines for the first time.

Development of WinGD’s ammonia-fuelled engine series has been advanced with strong support from shipowners, shipyards and engine builders. The first engine to be developed, the 52-bore X52DF-A, will be available for delivery from Q4 2024 and is applicable to a range of vessels including gas and bulk carriers.

WinGD CEO Dominik Schneiter said: “Time is of the essence as shipping looks to clean power solutions. This approval shows the industry that WinGD is leading the way in bringing carbon-free ammonia power to the deep-sea fleet. With the support of expert partners including Lloyd’s Register, these technologies will be available long before emission targets require them, giving operators vital space to plan and gain experience.”

Lloyd’s Register CEO Nick Brown added: “The maritime industry needs to trust that new technologies can be deployed safely as it continues to evaluate multiple transition pathways. This AiP will give first movers confidence that, subject to subsequent care in design, build, integration and operation, this ammonia two-stroke engine can help meet that demand. LR is delighted to have worked with WinGD on this groundbreaking development.”

WinGD was able to validate to Lloyd’s Register experts that the X52DF‑A concept is technically ready to satisfy future regulatory requirements with no major obstacles. As part of the AiP process, Lloyd’s Register considered the engine safety concept, risk assessments and preliminary engine and fuel supply system design, as well as confirming the compatibility of materials with ammonia fuel.

WinGD will extend the X‑DF‑A platform to a 72-bore variant in 2025 followed by other engine sizes in 2026 according to market needs, accommodating a wide range of vessel types from small tankers and car carriers to very large tankers. The engines operate according to the Diesel principle in both diesel and ammonia modes, have the same rating field as WinGD’s existing Diesel engines and will be available with the same cylinder configurations.