Thomas the Tank Engine (1973) was an animated musical television series planned by Andrew Lloyd Webber and animated by Brian Cosgrove in 1973 and cancelled in 1977 because the American market did not show interest.
Until now, the only thing we have are his a mention of this pilot in the book The Thomas the Tank Engine Man, and two pictures of this pilot.
After the 1953 disaster that was The Sad Story of Henry on the BBC, People were still interested to bring Awdry's books to life. Andrew Lloyd Webber had read The Railway Series when he was a young child and he approached Kaye & Ward (the publishers of The Railway Series). This adaption was going to be a musical (Unlike the planned 1953 series) and was going to be animated in a style similar to shows like Ivor the Engine and later on Monty Python's Flying Circus and the (extremely) controversial Comedy Central show, South Park. One of the songs of the series was going to be like this
"Come take a ride with the eight famous engines
Famous and Faithful and driven by steam
Each one is run by the branch line Controller
Each part of his scheme
The Fat Controllerʼs team..."
The Pilot was finally finished in 1976 and but the American market didn't seem very interested or how Awdry put it "Once the Americans get hold of it the whole series would be vulgarised and ruined!"
The project was abandoned in the next year (1977) and in 1984 The Railway Series books were brought to television by Britt Allcroft, unlike the first 2 version this one was successful as the saying goes "Third times the charm"
The songs Webber made for the series did not go to waste, as they were adapted into the 1984 musical Starlight Express.