“With DfT keen to hold winning bidders to their deals, franchise bidders cannot risk new technology that doesn’t work.”

franchise bidders. With DfT keen to hold winning bidders to their deals, they cannot risk new technology that doesn’t work. Muldoon points to the importance of DfT’s Invitations to Tender (ITTs) for franchises in encouraging innovation. They can be written to make it clear what DfT wants to buy, so Muldoon is out to convince DfT that hydrogen is the way forward.

It has a reputation for being expensive, but that depends on how it’s made. It can be a by-product of industrial processes, which might make it sensible to hold trials in the North West or North East of England, close to areas of chemical production. It is also made by electrolysis of water. This could be cheap if it uses unwanted electricity - for example, that produced by wind farms at night. Other methods produce carbon dioxide, which negates the compared with equivalent ordinary trains.

Mireo should be able to bridge overhead catenary gaps of up to 80km. This distance is too small to make fuel cells economic, but they come into their own above this threshold where the cost and weight of extra batteries becomes uneconomic. Thereafter, range is limited only by the hydrogen carried on board. Mireo can also run as a conventional EMU using catenary.

Between these three major manufacturers, Hitachi, and smaller players such as Vivarail converting former London Underground trains into hybrids, Britain’s rolling stock is set for major change. The result should be cheaper and greener trains that only need major infrastructure investment to provide space for more of them to run. There remain plenty of challenges to overcome.