A £170m plan to build a line between the proposed Terminal 5 at London’s Heathrow Airport and Railtrack’s Southern Zone at Staines has been endorsed by British Airways, airport operator BAA and Railtrack. The three signed a Memorandum of Understanding on September 13 to launch operational and environmental investigations, which would lead to an application for an Order under the Transport & Works Act to build the line, known as Airtrack.

T5, which still awaits planning approval, is to be served by a branch of the Heathrow Express line. Airtrack would extend this west and south on to the abandoned formation of the line from West Drayton to Staines West, parallelling the M25 motorway. T5 would be only 4min from Staines. From there, trains could head west to Reading taking 35min, south to Woking (23min) and Basingstoke (42min), or east to provide an alternative route into London termini at Victoria or Waterloo (30min).

Heathrow Express is electrified at 25 kV AC and the Southern Zone at 750V DC third rail. Dual-voltage stock could run through services via Heathrow, between Norwich and Bournemouth, for example. However, Airtrack is unlikely to be completed before 2008.