Asturias56.....the idea of a "short " taxi at LHR is new one onto me - sometimes I could be halfway through Lord of the Rings in the time it takes to line up.
London Heathrow is a very large and very busy airport, and the runways are each over 2 miles long. So if you have to taxi from one end of the airport to the other before lining up, owing to the wind direction, it might take a while.......