Great Western Railway’s innovative fast-charge battery train trial could transform UK’s railway

The fast-charge technology, which has been rigorously developed by specialist engineers over the past three years, solves the problem of delivering reliable, battery-only trains capable of fulfilling timetable services on branch lines, eliminating the use of diesel traction.

The system is capable of delivering charging power of up to 2,000kW – that’s eight times more powerful than Tesla’s Supercharger. At West Ealing, where the technology will be trialled in a real-world environment for the first time this spring, the train will charge for just 3 ½ minutes before restarting its journey on the Greenford branch line.

View B-roll footage of the battery train here

The use of batteries for extended operation has typically been constrained by their range and meant widespread implementation has, until now, not been possible. It also negates the need for overhead electric lines which are expensive and impact the landscape.  

The industry-leading trial could pave the way for battery-only trains to operate on branch lines across the UK and help meet the Government and wider rail industry’s target to reach net-zero carbon emissions by 2050.

GWR Engineering Director Dr Simon Green said:

“This work has never been done before and we’re leading the way to help the Department for Transport and Network Rail understand what is required to roll out this technology on the UK’s rail network.

“Only now has there been a combination of battery capability and charging technology that enables a branch line train to operate to the same timetable as a diesel unit, and yet still charge safely and with minimal impact on the local grid power supply.

“Clearly our specialist engineering team have been working round-the-clock to ensure that this fast-charge system has been fully tested and that there will be sufficient charge for the train to operate to the timetable on the Greenford branch line.

“Each branch line will vary but this is an incredibly exciting innovation and I’m proud that GWR is at the forefront of the railway’s commitment to phase out diesel-only traction by 2040.”

Rail Minister Huw Merriman said:

“We're ambitious about making the railways even more sustainable and this trial, backed by Government funding, could pave the way for greener journeys for millions of passengers across the network.

“Rail is already the most environmentally-friendly form of public transport and battery-powered technology will play an important role in further decarbonising it, helping us reach our net-zero target by 2050.”

Network Rail Interim Regional Managing Director, Rob Cairns, said:

“This trial marks an important milestone in sustainable travel in the UK. Rail is already the greenest form of public transport and battery-powered trains have the potential to play an important role in our commitment to a low-emission railway, with a goal of reaching net-zero by 2050.”

Unlike other charging technologies, the fast-charge system can be installed between the running rails in a matter of hours, with minimal disruption to the existing service or, in the case of West Ealing, no disruption at all.

It uses short charge rails which are fully covered by the train and are only live when the train is charging. This is very different to third-rail systems where the rail is live all the time and is arguably a safer approach to take.

The train charges from the charge rails using retractable shoegear (electrical contact pads) fed by two track-side battery banks. These are continuously ‘trickle-charged’ from the grid with a 63 Amp connection akin to a domestic supply.

GWR has already carried out simulations on other branch lines in the Thames Valley to explore how it could be rolled out even further in the future. This could reduce GWR emissions alone by over 1,700 tons of CO2e per year.

It is hoped the technology could one day see battery-powered trains in operation across the UK’s approximately 2,000 miles of 80-plus branch lines.

After more than 1,500 hours of testing at Long Marston Rail Innovation Centre, GWR’s Class 230 battery train this week began a series of test runs on the network.

The test runs will operate between Long Marston, Evesham, Honeybourne and Moreton-in-Marsh.  The train then makes its way to Reading Train Care Depot ahead of its move on to West Ealing.

Background

In February 2022, GWR signed a deal with Vivarail to trial new battery-charging technology designed to support the wider introduction of battery-powered trains on the UK’s rail network.

After Vivarail entered administration in December 2022, GWR agreed contracts to buy intellectual property, rolling stock and equipment relating to the fast-charge technology.

Charging rails and lineside battery banks have been installed at West Ealing in preparation for the start of the trial on the Greenford branch line.

Once the trial commences it will run in non-passenger service alongside scheduled passenger services.