Visible crew/equipment: As Henry crashes into the goods train, a crew member's hand can be seen pushing him, at the left side of the screen.
Continuity mistake: When Henry leaves the docks, there's nothing on his footplate, but when he's out of the docks, there are suddenly 2 lamps on his footplate.
Visible crew/equipment: As Henry approaches the green signal, the edge of the set is seen in the distance.
Answer: Breakdown trains help the engines back on track.