IRISH Rail (IÉ) has signed a contract with Digas, Latvia, to retrofit a class 071 diesel locomotive with a hydrogen internal combustion engine as a proof of concept under a €1.5m project.

Digas will manufacture, deliver and install the hydrogen internal combustion engine retrofit that will convert the diesel locomotive to hydrogen power. IÉ will provide the workshop necessary for installation, testing and commissioning activities and will test the retrofitted locomotive.

IÉ will also identify project partners that will provide hydrogen refuelling equipment for the retrofitted locomotive.

The partners state that unlike other hydrogen fleet projects in the rail sector that rely on fuel cells or specially produced hydrogen engines, this project will showcase the use of hydrogen in the locomotive’s existing internal combustion engine. “The project requires minimal adaptations to the locomotive, and if successful, will showcase a more practical and cost-effective way to decarbonise and run the existing diesel locomotive fleet,” the partners note.


The project is currently in the design phase with two testing phases scheduled for 2024 and 2025. Phase 1 will focus on static testing of the locomotive to check power and emissions output. The second phase, which will commence in 2025, will focus on service trials on the IÉ network. All designs and testing standards are subject to approval from the Commission for Railway Regulation (CRR).

“IÉ has 18 class 71 diesel locomotives in operation, 12 of which are used to support freight operations,” says Mr Jim Meade, IÉ chief executive. “If the conversion tests are successful, these locomotives can be converted to greener and more efficient alternatives.”

IÉ and Digas are jointly funding the project, with co-funding provided by EIT Urban Mobility, which is part of the European Institute of Innovation and Technology and Mechanical Engineering Competence Center, a Latvian body receiving the funding from the European Recovery and Resilience Facility.

“We see the same challenge over and over again with all railway operators - the need to decarbonise their operations but having an extremely long lifecycle of their assets which still runs on diesel fuel,” says Petro Dumenko, CEO and co-founder of Digas. “This project will showcase a cost-effective and practical way for operators like IE to decarbonise their existing fleet of diesel locomotives.”

The October edition of IRJ will include a feature article on Digas’ hydrogen retrofit activities.