Transport for London (TfL) has signed a £1.5bn contract with Siemens to design and build a new fleet of Piccadilly Line trains after the High Court lifted a temporary restriction that had put it on hold.
TfL first announced it was awarding Siemens with the contract in June, but its ability to sign the contract was put on hold after rival developers Bombardier and Hitachi launched legal action against the decision.
Last month the High Court lifted the temporary restriction that had prevented TfL from physically signing the contract with Siemens, but it is understood that the legal dispute has not been resolved in the long term.
The Piccadilly Line upgrade will mean that the old 1970s-built fleet will be replaced with 94 new trains that will be more spacious, air conditioned and have walk-through carriages and improved accessibility.
The contract will also allow Siemens to build a new factory in Goole, East Yorkshire, creating thousands of jobs.
One of the reasons Bombardier objected to TfL's decision was because it already had a factory in Derby where it could make the trains.
TfL said it expects the trains to be delivered in 2023 and in service by 2024. It aims to run a service of 27 trains per hour by 2026 – equivalent to one train every 135 seconds at peak time.
The Piccadilly Line contract paves the way for Siemens to build trains for all four deep Tube lines, including the Bakerloo, Central and Waterloo & City services, which TfL said would allow it to "maximise cost savings through greater standardisation of train operations, staff training, equipment, spares and maintenance".
Managing director of London Underground Nigel Holness said: “The introduction of new trains on the Piccadilly Line will significantly improve the journeys of millions of our customers, providing more frequent and more reliable trains for decades to come. This order will mean the replacement of the 1970s Piccadilly Line fleet, with delivery of the new trains in 2023, and will help address crowding on the line as London’s population continues to rise.”
A spokesperson for Hitachi said it would "vigorously pursue claims for damages against London Underground in court".
They added: “Failings with London Underground’s procurement, which has been challenged in the court by three different manufacturers, mean that Londoners will be paying a higher price for an inferior tube train.
"The train we put forward offered a more advanced design and better value for money, and would therefore have provided a greater boost to the economy in London and the rest of the UK."
TfL is currently facing criticism over the poor state of its finances. The transport body is facing a £1bn operational deficit this year, and board papers released last week show that its cash balance has decreased by £724m over the year to date.