The last train of the new S Stock fleet has been delivered from Bombardier’s site in Derby to London Underground’s Ruislip depot.
The new fleet is one of the components of a major upgrade of the sub-surface lines, known as the Four Lines Modernisation (4LM) project.
As well as the S Stock fleet – the first Underground’s trains to include walk-through carriages and air conditioning – the Circle, District, Hammersmith & City and Metropolitan lines will be deploying a CBTC signalling system designed to increase capacity by a third.
The project’s principle contractor is Thales, which has delivered a similar system on the Jubilee and Northern lines.
The majority of the S Stock fleet is already in service. However, all of the 192 trains will have to return to Bombardier’s Litchurch Lane factory to have the in-cab signalling system installed – a process which has already begun.
London Underground had originally placed an order for 191 units to replace the current D Stock but later revised it up to 192 in anticipation of the opening of an extension of the Metropolitan line to Watford Junction in 2020.
By spring 2017, the D Stock fleet will have been completely phased out.
Mark Wild, London Underground managing director, said: “The delivery of the final 192nd S-Stock train is a landmark moment in the history of London Underground, bringing us one step closer to modernising the oldest metro lines in the world.
“Once the new signalling system is complete in 2023, our customers will benefit from faster, more frequent and more reliable journeys.”