Goofs

Flash Harry's surname is said to be Hackett. However, in both Blue Murder at St. Trinian's (1957) and The Pure Hell of St. Trinian's (1960), it was given as Edwards.

At the board meeting, the position of the carafes, glasses and ashtrays varies between the general view and the close-ups.

When Harry is in the signal box to stop the robber's train he pulls a lever back toward him and we then see the signal drop to danger. After the girls have uncoupled the wagon, he pushes the lever forward again and the signal returns to clear. These actions are the wrong way round. Signal levers are pulled back to raise the signal to clear, pushed forward again to return to danger.

Towards the end, the three trains are travelling backwards and forwards on the up and down lines, two of these are steam trains and the passenger train is electric. However there is no third rail to provide electricity for the passenger train.

Correction! The "electric train" is actually Diesel Electric, which means it carries an engine to generate electricity to drive it. Therefore it does not require a third rail.