5) Now here’s another new train, but of an entirely different kind. The Royal Scot travels 400 miles from London to Glasgow. This electric train travels between Liverpool Street and Shenfield, about twenty miles north east of London on the railway to Chelmsford and Colchester. Liverpool Street is one of the busiest passen-ger stations in Britain, and until this new electric service was opened in September 1949, by the Minister of Trans-port, the passengers were all carried in steam trains.

You’ll notice that this train, which is just entering Shenfield Station, takes its power from overhead cables through an apparatus on the roof, which is known as a pantograph. The train is made up of nine coaches, and there’s a pantograph and electric motor in the front of every three coaches.

But perhaps you are more familiar with electric trains which pick up their power from a third rail...