The WAGR Dm Class was a type of 4-6-4T tank engine used by the Western Australian Government Railways from 1945. It was based on the earlier D class but differed significantly in the addition of large boiler-length side tanks, and was built by converting older E Class tender locomotives. The Dm Class served on suburban workings around Perth until the end of steam of Western Australia's railways.[1]
The Second World War was a major setback for Western Australia's railway system. The need to move large numbers of troops and material had taken its toll on the ability of the railways to continue the construction of much needed motive power. During the war years only three new locomotives were built, to the S class design, and as much as a quarter of the WAGR's locomotive fleet was out of action pending maintenance. Much of it was over forty years old.[2]