Heathrow Express

Heathrow Express is a British airport express train service between London Paddington and Heathrow Airport, opened on 23 June 1998. It is owned by Heathrow Airport Holdings and operates a 15-minute non-stop service over an entirely new spur from the Great Western Main Line at Hayes & Harlington.

The service was operated initially with a fleet of dedicated Class 332 EMUs (Siemens, 14 four-car sets), replaced from 2020 by Class 387 'Electrostar' units leased from Great Western Railway, in turn being replaced by Class 345 Aventra units shared with the Elizabeth Line.

The Heathrow Express tunnel was the venue for a serious incident on 20 October 1994, the partial collapse of the New Austrian Tunnelling Method works, which delayed the line's opening by a year.