Gordon and the Engineer - S11-E6
Continuity mistake: When Gordon is at the signal box, he drops off his coaches on his track and leaves. When he comes back with the mechanic, the coaches are gone.

Starring: Alec Baldwin, Michael Brandon, Ben Small, Martin Sherman, Michael Angelis
Gordon and the Engineer - S11-E6
Continuity mistake: When Gordon is at the signal box, he drops off his coaches on his track and leaves. When he comes back with the mechanic, the coaches are gone.
Plot hole: When Duck and Diesel leave the shed, Diesel follows Duck instantly, but the tracks they are on both lead to the turntable. As they are on different tracks to each other, it would be impossible for Diesel to follow Duck that quickly as the turntable could only be set to one track at a time.
Duke: Excuse me. Are you a vandal? Driver told me vandals smash and break things.
Trivia: The events of this episode were remade in CGI for the 2015 special, The Adventure Begins.
Question: How did they get the broken down train at the scene of the crash without any calls?
Answer: Breakdown trains help the engines back on track.