HydroFLEX is the first hydrogen-powered train to operate on the UK's network.

The project was initiated by rolling stock owner Porterbrook and the Birmingham Centre for Railway Research and Education in response to the UK government’s challenge to remove diesel-only trains from the national network by 2040.

Using a Class 319 electric multiple unit, the HydroFLEX demonstrator unit was fitted with hydrogen fuel tanks, a fuel cell and battery pack to provide a source of traction power capable of operating with zero carbon emissions.

In September 2020 the first HydroFLEX unit successfully started the first phase of mainline testing, achieving top speeds of 50mph.

Safety and certification expertise

The fuel cell unit is powered by hydrogen stored in high pressure tanks and oxygen sourced from ambient air. The cell converts the mixture and generates electricity of up to 100kW for traction while only creating emissions of pure water as a by-product.

Two lithium ion battery packs store electrical energy which powers the train’s existing traction systems throughout the operational duty cycle.

Before testing the vehicle's performance on Network Rail's mainline infrastructure, it needed to be approved by an EN17065 accredited certification body and an EN17020 accredited inspection body.

Ricardo fulfilled both requirements. Our rolling stock experts prepared the vehicle's Safety Case. Colleagues in Ricardo Certification, an independent accredited business within the Ricardo group, undertook an assessment in accordance with RIS-2700-RST, producing an Attestation Statement along with the Safety Assessment Report as the project’s appointed Assessment Body.