I was reading the CANADIAN RAIL OPERATING RULES - which is apparently the kind of thing you have time to read in retirement - and was fascinated by the section on Hand Signals, that one rail worker would use to communicate movements to the locomotive engineer.

(Once I master these, I’m going to try to understand Canadian Football League referee signals.)

Here are a few -

• STOP: Swung from side to side at right angle to the track.

• MOVE BACKWARD: Swung in a circle at right angle to the track at a speed in proportion to the speed required.

• MOVE FORWARD - Raised and lowered at a speed in proportion to the speed required.

However I think my favourite might be this note:

Any object waved violently by anyone on or near the track is a signal to stop.

That is surely useful advice for all situations, not just train movements.