Network Rail will undertake new infrastructure enhancements and surface works on London’s Crossrail project as part of a contract worth £2.3bn.
Network Rail will carry out above ground elements of the Crossrail project to ensure a smooth service to Maidenhead, Heathrow, Abbey Wood and Shenfield.
The work includes modifications at 27 surface stations, power infrastructure, such as overhead lines, and the building of a larger flyover at Stockley in Hillingdon to enable Crossrail services to operate to Heathrow.
Crossrail surface director Matthew White said: "To enable Crossrail services to operate, Network Rail will be undertaking a multi-billion upgrade of the rail network with major improvements planned for the Great Eastern and Great Western main lines, including better stations, electrification, new and improved signalling and the integration of the new Crossrail tunnels with the existing railway."
Crossrail trains will pass through 37 stations and run 118km from Maidenhead and Heathrow, via new twin-bore 21km tunnels below central London to Shenfield and Abbey Wood.
The company said that the Crossrail service is expected to offer the ability to travel directly to the West End, the City and Canary Wharf.
Network Rail is also responsible for the design, development and delivery of the parts of Crossrail that are on the existing network.
Work under the project will also include upgrading 42 miles of track, redeveloping 27 stations, and renewing ten bridges.
Crossrail services, scheduled to start through central London in 2018, are expected to increase the city’s rail-based transport network capacity by 10%, supporting regeneration and cutting journey times across the region.