This vintage railway film, produced in association with the Central Office of Information, the British Locomotive Allied Manufacturers' Association and the British Electrical Manufacturers' Association, covers the transition from steam to new forms of motive power, and its effects on railwaymen and passengers.

Britain once operated the most experienced diesel and electric railway in the world. Almost two centuries ago, she invented the steam engine as we know it today and introduced a new system of transport. In only nine years, in the middle part of the 20th century, British Rail and the British locomotive industry designed, built and tested enough diesel and electric locomotives to replace fifteen thousand steam engines.

A short clip has been trimmed from the middle of this movie, as the BBC has seen fit to claim copyright over a 20 second segment of a public domain film. If this film was not trimmed, it would not have been able to be viewed in Great Britain. Hopefully it does not affect the flow of the movie to a great degree.