'Driverless' Tube trains: See inside TfL's new fleet for London Underground

Trains will be first ‘walk-through, air-cooled’ carriages on deep-level lines

A fleet of 250 new 'driverless' Tube trains will be introduced onto the network in the mid-2020s (TfL)

Plans for a fleet of “driverless” Tube trains have been unveiled by Transport for London (TfL).

The fleet of 250 trains, which are not expected to be in service on the Tube until the mid-2020s, will start out with an operator on board, but will be designed and built to be “capable of fully automatic operation”.

The trains are part of what Mayor Boris Johnson has called the “New Tube for London”, the plans for which claim will increase the passenger capacity by thousands.

New technology will see the air-cooling feature already in use on the Metropolitan and District lines extended to deep-level lines for the first time, while the new trains’ carriages will be “walk-through”, appearing similar to the current Circle and Hammersmith & City Line trains, with wider doors to let people get on and off the trains quicker.

The trains will be rolled out across the Central, Bakerloo, Piccadilly, and Waterloo & City lines, and alongside planned signalling improvements promise to provide Londoners with faster, more frequent and more reliable services.

When the trains eventually join London’s Underground network, they are intended to be in service for 40 years.

The new train designs are currently on display in London's King's Cross St Pancras Underground station as part of a public exhibition.