Rapid-charging battery train trials under way

The new trains are converted from old Underground ones

Battery-powered trains using a new rapid-charging system are being tested as part of a trial by Great Western Railway (GWR).

The trains use the onboard FastCharge battery that delivers the equivalent of a full charge for a car in 85 seconds, and it is hoped they could help replace their diesel counterparts.

They are converted from old Underground trains and are being trialled in west London - but are expected to be eventually rolled out in the Thames Valley.

Simon Green, GWR's engineering director, described the more environmentally friendly trains as a "really good solution".

The trials have taken place without fare-paying passengers, who will have to wait until the spring

GWR's railway franchise includes the west and south west of England, as well as routes between London and Didcot, Oxford, Reading and Windsor.

Mr Green said: "The environment in this train is just as good as it is in the diesel train. Some might argue it’s slightly better.

"Therefore, from a passenger’s perspective... it takes you along that path of decarbonisation and it allows us ultimately to remove diesel trains from those services and that environment."

He said that "most customers and most neighbours of the railway" would be "really pleased" to see such changes.

The charging system is utilised before the trains head off on the return leg of their journeys

The charging system is utilised before the trains head off on the return leg of their journeys.

It means the trains do not rely on a third rail or overhead wires, such as those on the Elizabeth line.

Trial manager Julian Fletcher explained: "The train comes to a halt, and then the rails become powered, and then they charge up the train, and that all happens within the minutes it takes the driver to get out of one end and in the other."

He said a lot of tests were carried out successfully before the installation of the charging equipment, including some that "covered ice, snow, and all sorts of contamination".

GWR has many similar carriages ready for conversion, including older Underground trains.

Fare-paying passengers in west London are expected to ride the new trains from the spring.