British Rail Class 345

The new depot built for class 345s at Old Oak Common

In 2008, the British government's rolling stock plan stated a requirement for around 610 carriages for Crossrail, expected to be similar in design to the Thameslink rolling stock, to meet the design improvement requirements of the 2007 "Rail Technical Strategy" (RTS), including in-cab signalling/communication with satellite and European Train Control System level 3 technologies, regenerative braking, low cost of operation and high reliability, with low weight and high acceleration.[7][8]

The publicly released specifications included a passenger capacity of 1,500, with 450 seated, in a fully air-conditioned train no longer than 205 m (673 ft) with a top speed of 145 km/h (90 mph), and an energy efficiency as good as 24 kW·h per train-kilometre. Tests on the finished trains indicate that the energy efficiency target has been exceeded, with Class 345s consuming only 14 kW·h per train-km.[9] The trains will work with platform screen doors in the central tunnel section.[5] The capital value of the contract, which included construction of a depot at Old Oak Common, was estimated at around £1bn,[10] the total value may be greater due to the winning bidder expected to undertake maintenance of the trains for three decades, the estimated lifespan of the fleet.[11]

The procurement programme was launched in December 2010. The package valued at approximately £1bn was for 70 ten-carriage trains with a capacity of about 1,500 passengers and construction of maintenance depots.[12]

In March 2011, Crossrail announced that Alstom, Bombardier, CAF, Hitachi and Siemens had been shortlisted. The initial bidding process was expected to start in late 2011, with a contract decision in 2013.[13][14]

In August 2011, the invitation to tender was delayed by one year to 2012 and the contract decision to 2014, with the introduction of trains on the Great Eastern Main Line expected from May 2017 (previously December 2016), with a correspondingly shortened production schedule. The delay was a cost-saving measure to avoid new vehicles being unused whilst Crossrail tunnelling was completed;[15] it also postponed bidding until after a review of governmental procurement processes.[16][17] Alstom withdrew from the bidding process in August 2011, stating it lacked a suitable developed product.[17] Concerns about taxpayer value for money on PFI funded projects led to Transport for London (TfL) seeking to purchase the trains outright.[18] In December 2011 the request to raise the debt ceiling at TfL to allow the acquisition with public funds was refused by the Department for Transport.[19]

In February 2012, an invitation to negotiate was issued, which included clauses on 'responsible procurement' relating to UK supply chain sourcing and training opportunities;[10] the procurement became politicised after Bombardier failed to win the Thameslink rolling stock contract, and said it may have to close its UK assembly plant (Derby Litchurch Lane, at the time the only operational rolling stock manufactory in the UK) if it did not win the Crossrail contract.[11][20]

Formal bids were expected in mid-2012, with a decision in early 2014, based on the proposed product meeting the design requirements, and on value for money. Procurement was expected to be partly public and partly privately financed.[10] In September 2012, the government announced that it would underwrite a further £240 million of the project cost under its 'UK Guarantees' infrastructure credit funding scheme, in addition to the 30 per cent of the project being government funded.[21] Siemens withdrew from the tendering process in July 2013, citing a likelihood of insufficient production capacity in the production timeframe.[22]

In December 2013, the European Investment Bank (EIB) agreed to provide loans to Transport for London for the rolling stock of up to £500m.[23] On 6 February 2014, it was announced that Bombardier Transportation had been awarded a £1bn contract to supply 65 trains,[4][24] with an option for 18 more.[4] The trains were constructed at Bombardier's Derby Litchurch Lane Works,[25] with testing scheduled to begin in May 2016.[26] On 29 July 2016, the first completed train was unveiled by Bombardier and Transport for London at Derby Litchurch Lane.[27]

In March 2018, an option for five more units was exercised taking the order to 70 units.[28]

In January 2018 it was proposed that the fleet would be sold by TfL and leased back in order to provide funding for the New Tube for London.[29] This £1bn, 20 year sale and leaseback deal was agreed in March 2019.[30]