Class 345

The Class 345 Aventra is a type of electric multiple unit built by Bombardier Transportation for use on London's Elizabeth Line. The contract for their delivery was awarded as part of the Crossrail project in February 2014, and a total of 70 nine-car units – each able to carry 1,500 passengers – were constructed in Derby between 2015 and 2019, at a cost of over £1 billion. The first unit entered service on 22 June 2017.

345001 at Abbey Wood, en route to Paddington.

History

In 2008, the British government's rolling stock plan called for approximately 610 carriages for Crossrail, designed to be similar to the Thameslink rolling stock. This design was intended to meet the enhancements outlined in the 2007 "Rail Technical Strategy" (RTS), including in-cab signaling and communication with satellite and European Train Control System level 3 technologies, regenerative braking, low operational costs, high reliability, light weight, and high acceleration.

The public specifications detailed a passenger capacity of 1,500, with 450 seats, in a fully air-conditioned train no longer than 205 meters (672 feet 7 inches), featuring a top speed of 145 km/h (90 mph) and an energy efficiency of up to 24 kWh per train-km. Tests on the completed trains showed that the energy efficiency target was surpassed, with the Class 345 consuming only 14 kWh per train-km. The trains are compatible with platform screen doors in the central tunnel section. The contract's estimated capital value, which included building a depot at Old Oak Common, was around £1 billion. The overall value may be higher due to the expectation that the winning bidder will also maintain the trains for three decades, the estimated lifespan of the fleet.

Bidding process and funding

In March 2011, Crossrail revealed that Alstom, Bombardier, CAF, Hitachi, and Siemens had been shortlisted for the rolling stock contract. The initial bidding process was scheduled to begin in late 2011, with a contract decision anticipated in 2013.

By August 2011, the invitation to tender was postponed by one year to 2012, and the contract decision was delayed until 2014. This adjustment also shifted the expected introduction of trains on the Great Eastern Main Line to May 2017 from the previously planned December 2016, resulting in a shortened production timeline. This delay was implemented as a cost-saving measure to prevent new vehicles from sitting idle while Crossrail tunneling was completed and to allow time for a review of government procurement processes. Alstom withdrew from the bidding in August 2011, citing the absence of a suitable developed product. Additionally, concerns over the value for money of PFI-funded projects prompted Transport for London (TfL) to explore purchasing the trains outright. However, in December 2011, the Department for Transport denied TfL's request to raise its debt ceiling for acquiring the trains with public funds.

In February 2012, an invitation to negotiate was issued, which included requirements for 'responsible procurement,' such as sourcing from the UK supply chain and providing training opportunities. The procurement process became politically charged after Bombardier, which had not secured the Thameslink rolling stock contract, suggested that failure to win the Crossrail contract might lead to the closure of its UK assembly plant (Derby Litchurch Lane), then the only operational rolling stock manufacturer in the UK.

Formal bids were expected by mid-2012, with a decision anticipated in early 2014, based on how well the proposed products met design requirements and provided value for money. The procurement was expected to involve both public and private financing. In September 2012, the government announced it would back an additional £240 million of the project cost through its 'UK Guarantees' infrastructure credit funding scheme, complementing the 30 percent government funding already allocated. Siemens withdrew from the tendering process in July 2013, citing concerns about insufficient production capacity within the required timeframe.

Contract award and Construction

In December 2013, the European Investment Bank (EIB) committed to providing up to £500 million in loans to TfL for the rolling stock. On 6 February 2014, it was announced that Bombardier Transportation had secured a £1 billion contract to supply 65 trains, with an option to supply an additional 18 trains. These trains were manufactured at Bombardier's Derby Litchurch Lane Works, with testing scheduled to commence in May 2016. On 29 July 2016, the first completed train was unveiled by Bombardier and TfL at the Litchurch Lane facility.

In March 2018, an option was exercised for five additional units, bringing the total order to 70 trains.

Further to this, following the launch of the Elizabeth line, TfL has seen significant passenger growth. TfL has indicated that additional capacity will be necessary when Old Oak Common railway station opens in the 2030s, coinciding with the commencement of High Speed 2. To address this need, TfL sought funding from the Department for Transport for extra trains. Both Alstom and Unite the Union advocated for an additional order, as the lack of national train orders had jeopardized the future of Alstom's Derby Litchurch Lane plant.

In June 2024, a £370 million contract was signed for 10 additional 9-car trains, along with their maintenance until 2046. The Department for Transport contributed £220.5 million to this contract.

Sale and leaseback

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. This £1bn, twenty-year, sale-and-leaseback deal was agreed in March 2019 with NatWest, SMBC Leasing and Equitix.

Operations

The first train entered service on 22 June 2017, operating as a seven-car unit on the eastern TfL Rail route between London Liverpool Street and Shenfield. Full nine-car trains could not be accommodated at the Liverpool Street terminus until platform extensions were completed in 2021.

The trains began service on the western TfL Rail route between London Paddington and Hayes & Harlington in May 2018 and extended to Reading by December 2019. Initially, trains on the western route were delivered as seven-car units but are being progressively converted into nine-car formations.

These new trains have entirely replaced the Class 315 units previously used on TfL Rail services to Shenfield. They have also largely replaced the Class 387 units of Great Western Railway on services to Reading and fully replaced the Class 360 units of the former Heathrow Connect service to Heathrow. The new trains offer free Wi-Fi, 4G connectivity, and full accessibility for wheelchair users.

In May 2020, the Office of Rail and Road (ORR) authorized the operation of Class 345 trains into Heathrow Terminals 2 & 3, Terminal 4, and Terminal 5. Service commenced on 30 July 2020. On 24 May 2022, the trains began operating in the central core section under the Elizabeth line brand, transitioning from the TfL Rail designation.