Stanley came to Sodor to join the fleet of the Mid Sodor Railway after the First World War. Built by the Baldwin Works, he served during the war, and was later bought by the Mid Sodor Railway for use on the line. Even after being regauged, Stanley proved to be a rough runner, he was later converted for use as a pumping engine in one of the mines.
In December 1946, Stanley failed and the mine flooded. With all revenue earning gone, the Mid Sodor closed and Stanley was scrapped.
When building his model of Ulfstead Road, Stanley was built for use on the layout, but was plagued with problems, most of which were to do with the engine derailing and bouncing. Awdry rebuilt him into a 0-6-0PT for ease of running, and used him like that until the chassis died. When this happened, Awdry removed the motor and made Stanley a static model.