Tender documents have been issued that set out Crossrail’s requirements for new high-capacity rolling stock and associated depot at Old Oak Common.
A key feature of the Crossrail trains is air conditioning and inter-connecting walk-through carriages.
The contract for 60 trains will be awarded in 2014.
Secretary of state for transport Justine Greening said: ‘This is an important step in making Crossrail a reality for millions of passengers who will use it every week. Once these 60 trains are operational, they will carry an additional 1.5 million people within 45 minutes of the heart of London, help the growth of the UK economy and create opportunities for new apprenticeships and jobs.’