Continuity mistake: The coal tender has the No.99 on it in some shots, or the letters "SP and QR" on others. Other times it has no number at all.
Continuity mistake: In close-ups, the train's engine carries the No. 651 in some shots, and No. 814 in others. In some long shots, the number is missing.
Continuity mistake: In long shots, the train cars can be seen with the letters "S.P.Q.R." on them. In close-ups, this changes to "South East and Western."
Trivia: When we see the train during the opening credits, look at the carriages and you can see they have names of Warner Brothers staff on them: "Frizby" (Friz Freleng), "Hawley" (Hawley Pratt), "Ross" (Virgil Ross) and "Champin" (Ken Champin).