One branch runs to Heathrow Central (for Terminals 2 and 3), Heathrow Terminal 4 and Heathrow Terminal 5, The main western section runs on the surface from Reading to Acton Main Line.Upgrades are being made to stations at Maidenhead, Taplow, Burnham, Slough, Langley, Iver, West Drayton, Hayes & Harlington, Southall, Hanwell, West Ealing, Ealing Broadway and Acton Main Line.The project that became Crossrail has origins in the 1943 County of London Plan and 1944 Greater London Plan by Patrick Abercrombie.These led to a specialist investigation by the Railway (London Plan) Committee, appointed in 1944 and reporting in 19.One of the two eastern sections runs underground from Whitechapel to Stratford, then on the surface on the existing main line.The service will replace the "Shenfield metro", with key stops at Ilford, Romford (for interchange with London Overground services to Upminster), Gidea Park (where some peak hour trains will start or terminate), and Shenfield.
The tunnelled sections will be approximately 22 kilometres (14 mi) in length.
In the east, the line splits at Whitechapel, with one branch running over the existing Great Eastern Main Line via Stratford to Shenfield, and the other branch running through Canary Wharf and emerging from the tunnel at Custom House on a disused part of the North London Line, continuing under the River Thames to Abbey Wood.
In the west the route connects with the Great Western Main Line at Paddington and runs to Hayes and Harlington, where it splits.
The central tunnels run from a portal just west of Paddington to Whitechapel, with further tunnelling to Stratford and to Canary Wharf.
There will be new stations at Paddington, Bond Street, Tottenham Court Road, Farringdon, Liverpool Street and Whitechapel, with interchanges with the London Underground and other National Rail services.
It was also suggested that the alignment of the tunnels should be safeguarded while a final decision was taken.