The British Rail Class 345 Aventra is a type of electric multiple unit passenger train built by Bombardier Transportation as part of the Crossrail project for use on the Elizabeth line. Seventy nine-car trains have been manufactured at a cost of over £1 billion, with each train able to carry 1,500 passengers. The contract was awarded to Bombardier in February 2014 and the first train entered service on 22 June 2017.