Northern says trials of a different style of train driving show that fuel consumption could be cut by 7 per cent, potentially saving £3 million a year.

The train operator has been working with specialists from Chrome Angel Solutions and auticon, who have developed a model to calculate the best speed and braking patterns.

The output of the model is then used to help train drivers change their driving styles to use less fuel while keeping trains on time.

Northern says early tests between Whitby and Middlesbrough identified the potential 7 per cent saving in fuel consumption, with the added benefit of an equal reduction in CO2 emissions.

Northern pays around £50 million a year for diesel, and so in theory the state-owned operator could save £3 million or more annually, although the precise benefits are likely to vary on different routes.

The tests have now been extended to the routes between Darlington and Bishop Auckland and Darlington and Saltburn, Newcastle and Hexham, Nunthorpe and Kildale, and Seaham and Middlesborough. The original test route from Whitby stays in the trials, but has been extended from Middlesbrough to Newcastle.

Northern’s strategic development director Rob Warnes said: ‘Along with the rest of the rail industry, Northern is working towards phasing out diesel-only trains by 2040.

‘However, with only 25 per cent of our network electrified, diesel trains remain integral to our operation and, as such, we want to make sure we operate them in the most fuel-efficient way.

‘This has been a fascinating, year-long project and it’s great to see the proof on concept realised so that we can now expand trials and build the case for implementation.’