NEW trains powered by electricity instead of diesel are now operating on the line between Maidenhead and London Paddington.

Six electric trains, known as GWR Electrostar trains, went live on Monday on the newly electrified line, which means they are powered through overhead power cables.

Great Western Railway (GWR) told the Observer that as the railway line is not electrified beyond Maidenhead, services would generally begin and terminate there or at Paddington, with services between Reading and Paddington still running on regular Turbo diesel trains.

In both cases the trains will continue to stop at Slough and various stations in South Bucks, depending on the service.

A GWR spokesperson said: “This is a temporary measure until the line is further electrified.”

GWR said the new electric trains had been fitted into the schedule and their services were in addition to those already offered on the line to London Paddington.

In total there are now eight electric trains on the network between Berkshire and London but only three will run at a time for now, carrying eight carriages each, responsible for 12 services between them.

In July this will be expanded to 16 services, before the line is electrified to Reading and Didcot Parkway by early 2018.

By the summer GWR says the new trains will increase seating capacity in the Thames Valley by 40 per cent – improving the number of seats during peak hours between Maidenhead and London Paddington.

GWR Managing Director Mark Hopwood said: “The Thames Valley is one of the most popular rail corridors in the UK. We have promised the current fleet would be upgraded to provide much needed additional capacity and more comfortable, quieter journeys.

“We started to run our first new electric trains between Paddington and Hayes & Harlington in September and increased this to a half hourly frequency at the start of the year. Today (Monday) I am delighted to announce that we have now extended these services to Maidenhead.”

The move is part of the biggest fleet upgrade in a generation on the Great Western network, costing £2.8 billion, and the project initially suffered long delays.

The electrification will gradually see Turbo diesels replaced with the Electrostar trains, which are built by Bombardier at their factory in Derby, and technically known as the Class 387.