Plans for Piccadilly line trains with walk-through, air-conditioned carriages are on track, Transport for London (TfL) has said.

New trains are expected to be introduced on the Tube line from the start of 2025, replacing the current fleet which dates back to the 1970s.

TfL said the new fleet would aim to boost capacity on each train by 10 per cent, as well as ensuring a smoother, quieter ride for passengers.

From mid-2027, the frequency of trains at peak times will rise from 24 to 27 trains per hour.

This will ensure a train runs every two minutes and 15 seconds. Combined with the increase in the number of people each train can hold, the Piccadilly line should be able to increase its capacity at peak times by 23pc.

Half of the new train fleet will be built in the Siemens Mobility factory in Goole, East  Yorkshire and it is expected that the first train will be delivered for testing this summer.

Harrow Times: Mayor of London Sadiq Khan last year during his visit to the Siemens Mobility factory which will manufacture new Piccadilly line trains Mayor of London Sadiq Khan last year during his visit to the Siemens Mobility factory which will manufacture new Piccadilly line trains (Image: PA Media)

Stuart Harvey, TfL’s chief capital officer, said: “The trains will be fully accessible and will significantly improve the experience of millions of customers with wider doors and walk-through, air-conditioned carriages for more comfortable journeys.

“While TfL is hoping to follow the introduction of new trains on the Piccadilly line with new signalling, and then to upgrade the rest of the Deep Tube lines, such large-scale investment will not be possible without continued capital investment from the Government from April 2024.

“TfL remains fully committed to upgrading the remaining Deep Tube lines - the Central, Bakerloo, and Waterloo & City lines – and will continue to work with the Government to make the case for long term investment in London to make it an even better, greener, safer and more successful place for everyone."

As part of the upgrade, TfL is committed to building new facilities at its Cockfosters depot in Enfield, including a maintenance shed and wheel lathe building.

A TfL spokesperson said: “The new Piccadilly line trains will need facilities to keep them well-maintained which is why we’re improving our depots at Cockfosters, Northfields and South Harrow.

"Prior planning approval for the work to upgrade the depot at Cockfosters was given in March 2022 but we re-submitted the application at the end of last year to include detailed proposals for a wheel lathe facility to ensure that the wheels of our 94 new trains are kept in good condition.

"Planning approval for this new facility was given earlier this month.”

Enfield Council confirmed that the application was approved on March 8.