In pictures: Building of London Underground trains rolling along

Bombardier will supply, deliver and maintain 65 new trains and a depot at Old Oak Common. Christopher Furlong / Getty Images

Transport for London is working with Bombardier on the final design for the Crossrail trains with the first due to be delivered in May 2017. Christopher Furlong / Getty Images

The new fleet of trains will be progressively introduced to the existing rail network well in advance of services commencing through Crossrail’s central section in December 2018. Christopher Furlong / Getty Images

At the Old Oak Common depot construction, the project will create 244 jobs and 16 apprenticeships. When fully operational, the depot will support 80 jobs to maintain the new fleet of trains. Christopher Furlong / Getty Images

Bombardier will supply, deliver and maintain 65 new trains and a depot at Old Oak Common. Christopher Furlong / Getty Images

Each Crossrail train being built by Bombardier Transport is just over 200 metres long, made up of nine carriages and able to carry up to 1,500 passengers. Christopher Furlong / Getty Images

Bombarderi's London Crossrail contract includes an option to purchase 18 additional trains. Christopher Furlong / Getty Images

Bombardier will supply, deliver and maintain 65 new trains and a depot at Old Oak Common. Christopher Furlong / Getty Images

Technicians work on London Underground trains at the Bombardier Transport manufacturing plant in Derby, England. Christopher Furlong / Getty Images

Bombarderi's London Crossrail contract includes an option to purchase 18 additional trains. Christopher Furlong / Getty Images

The Canadian transport giant Bombardier has a £1 billion contract to build and maintain a fleet of 65 nine-car electric multiple units for the UK’s Crossrail project.