The recording of the phrase "Mind the gap" dates from 1968, and is voiced by Peter Lodge, who owned a recording company in Bayswater.
He stepped in when the actor hired to record the lines insisted on royalties.
There have been several books, a gameshow, two theatre companies, several films and lots of songs called Mind the Gap.
While Lodge's recording is still in use, some lines use recordings by Manchester voice artist Emma Clarke, while commuters on the Piccadilly line hear the voice of Tim Bentinck, who plays David Archer in The Archers.
SOURCE: David Long 'The Little Book of London Underground'
A steam train which carried passengers in the 19th Century has returned to mark 150 years since the first tube journey.
A look back at some of the stops on London Underground's 150 year journey.
All day we've been adding fascinating facts about the Tube, which turns 150 years old this week. Now find out how much you know.