Last year we rode a funicular railway with a single overhead wire and a large bank of resistors on the roof that got very hot when it was descending. I'm guessing that it was a DC motor/generator setup with the resistors absorbing the generators output on the way down.

Today we rode a train with two overhead wires but no resistor banks. This train apparently runs on a three phase supply. Presumably the rails supplied the third "leg" of the supply but how safe is this with AC? Wouldn't the rails be dangerously live relative to earth?

There were no warning signs and the track was unprotected so it must be safe but I don't understand how. Can anyone explain? Also, how did the braking work?

https://en.m.wikipedia.org/wiki/Petit_train_de_la_Rhune

Tim