Thomas & Friends (1984)

Season 2: Episode 12

Duck is boasting about being Great Western and how useful he is, much to the annoyance of the others. Later, the Fat Controller introduces Diesel, a shunter who is "on trial". He asks Duck to show Diesel around, but Diesel says he doesn't need Duck. Duck leaves him to it and Diesel has an accident with some trucks. He thinks it's Duck's fault...