|This article is about the narrow gauge engine. You may be looking for the standard gauge engine.|
Douglas is a 0-4-0WT built in 1918 by Andrew Barclay and Co. Ltd. for the Airservice Construction Corps.
From 1921 until 1945, he worked at the RAF railway at Calshot Spit, Southampton. After a period in store at Calshot, he was bought in 1949 by Abelson and Co. Ltd. who presented him to the Talyllyn in 1953. After overhaul and alteration from 2ft to 2ft 3in gauge, he entered service in 1954 and was named "Douglas" at the donor's request. Although smaller than the other locos he has performed well and was returned to service in 1995, having been fitted with a new boiler, turned out in his old Air Ministry Works and Buildings livery.
Douglas spent many years painted red and blue and running under the guise of Duncan.
Douglas is currently painted RAF Blue with the RAF roundel painted on the sides of his boiler. In his appearance in the Railway Series, he was painted in the Talyllyn Railway's Bronze Green livery with black and yellow lining.
- Douglas' tall cab that scraped against the tunnels it ran through was an inspiration for the story of Home at Last. In addition, Douglas was known for being a rough rider due to its short wheelbase, which was what inspired Duncan's "rock 'n' roll" tendencies.