Work has begun on the Stockley Interchange in west London, a crucial part of the Crossrail network that will allow Crossrail services to operate to and from Heathrow.
Network Rail will build a new single track viaduct for all trains from Heathrow towards London. It will allow Crossrail trains to join the branch to Heathrow without delaying - or being delayed by - fast trains to the west, thus increasing capacity and reliability on the busy Great Western Main Line.
Network Rail is responsible for the design, development and delivery of the parts of Crossrail that are on the existing network, covering 70km of track and 28 stations from Maidenhead in the west to Abbey Wood and Shenfield in the east.
The current junction at Stockley is used by Heathrow Connect in both directions and Heathrow Express in the London direction. The viaduct will start on the western side of the existing airport lines. It will then cross over all of the tracks in the railway corridor, turning eastwards and will continue on the northern side of the railway tracks.
The viaduct will then widen and a junction for Crossrail and Heathrow Express services will be installed on the track. This junction will allow Heathrow Express services to cross above the slow lines and descend to main line track as at present. Crossrail services will remain on the northern side, descend on a second ramp and run on a dedicated track, which will then connect with the existing up slow line via a new junction constructed at a point just before Hayes & Harlington station.
The timetable for the works is as follows:
- Late March 2012 – Installation of a retaining wall begins
- February 2014 – Western flyover completed
- December 2014 – Northern viaduct completed
- September 2017 – Project completion