Cost of delayed Arterio train fleet withheld by government

The new Arterio train fleet had been due to start running in 2019

The government has refused to reveal the cost to the taxpayer of the delayed introduction of a new fleet of trains.

The Class 701 Arterio trains should have entered service with South Western Railway (SWR) in 2019.

However, the first passenger service ran between London Waterloo and Windsor in January.

The Department for Transport (DfT) said answering the BBC's Freedom of Information (FOI) request could "prejudice commercial interests".

The trains are designed to hold more passengers

The Derby-built carriages, originally ordered for £1bn, have been delayed by numerous software faults.

Other reported issues have included the coupling process, faulty windscreen wipers and cab doors that were difficult to open.

SWR has accepted 71 of 90 trains from manufacturer Alstom and is running three of them in a trial.

The BBC asked how much money was being paid to Rock Rail, the owner of the trains that are not carrying any passengers, as well as asking for the cost of storing unused trains.

We also inquired about the cost of retaining and maintaining other rolling stock where the leases have been extended to cover the absence of the new trains.

South Western Railway said it expected the full fleet to be running in 2025

The DfT replied: "The Department does hold the information you have requested."

But it would not release the numbers, stating: "Disclosure of the details of 701 cost delay would likely prejudice the commercial interests of South Western Railway and the Department."

It said it was required to balance the public interest in disclosing the information against that of withholding it.

SWR expects the rollout of the full fleet, along with training 769 mainline drivers, to take up to 18 months from January 2024.

The Class 701 trains will replace all other rolling stock on services connecting London Waterloo with Reading and Windsor, and throughout the busy south London suburban network as far as Guildford.

Follow BBC South on Facebook, X, or Instagram. Send your story ideas to [e-mail].