Visible crew/equipment: When the Fireflies form the engine, the end of the set is visible in the distance.
Visible crew/equipment: When Stepney puffs through the fog after dropping off the stone loads, studio equipment can be seen in the top left corner of the screen.
Visible crew/equipment: When Henry puffs under the bridge, studio equipment can be seen in the top left corner.
Visible crew/equipment: When Toad falls into the pond, in the shot from his point of view, studio equipment can be seen in the top left corner.
Answer: Breakdown trains help the engines back on track.