How electric subway trains work?

Question

How electric subway trains work?

Answer 1

Electric

Electric locomotives (engines) were invented about the same time as diesel engines. These engines use electricity to run. The electricity comes from a central plant. The engine gets the electricity through a third metal rail under the train, or from wires.

Electric engines are quiet and produce no smoke or exhaust. They can start and stop more quickly than steam or diesel engines. Electric trains are used all over Europe. In the United States we use diesel trains.

Answer 2

Alongwith the 2 rails there is a 3rd rail which runs parallel but on insulator. The 3rd rail is electrically charged and train gets current from 3rd rail using pantograpf type thing.

Answer 3

On the London Underground the trains have 2 running rails and 2 electric rails, 1 between the running rails and 1 on the outside. The train collects current from 1 rail - the pick-up is called a shoe - and returns it through the other.

Most underground railways use a similar system with 1 or 2 electic rails. In the system with 1 rail the return is through one of the running rails.

On the Glasgow Underground the trains are cable cars.