War Department (United Kingdom)

The War Department was the United Kingdom government department responsible for the supply of equipment to the armed forces of the United Kingdom and the pursuance of military activity.

One aspect of the War Department's work was the supply of locomotives and rolling stock for use on railways in the United Kingdom, other parts of the British Empire, and in theatres of conflict.

In World War I, the War Department ran the War Department Light Railways which were a system of narrow gauge trench railways used for the supply of ammunition and stores, the transport of troops and the evacuation of the wounded.

In World War II, large numbers of steam locomotives were produced, as well as some diesel locomotives, of varying gauges to suit the area of planned operation.

Of those that were sold, examples of three types ended up as part of the British Railways fleet (where they were often referred to as 'Austerity' locos): For more details see Steam locomotives of British Railways.