This 0-4-0WT was built in 1918 by Andrew Barclay & Co. Ltd. for the Airservice Construction Corps. From 1921 until 1945 it worked at the RAF railway at Calshot Spit, Southampton. After a period in store at Calshot it was bought in 1949 by Abelson & Co. (Engineers) Ltd. who presented it to the Talyllyn in 1953. After overhaul and alteration from 2ft to 2ft 3in gauge, it entered service in 1954 and was named ‘Douglas’ at the donor’s request. Although smaller than the other locos it has performed well and was returned to service in 1995, having been fitted with a new boiler and turned out in its old Air Ministry Works & Buildings livery.
On 21st February 2018, it was the 100th Birthday of ‘Douglas’. To commemorate the centenary a new livery reflecting its RAF heritage was commissioned.
CURRENT STATUS: Boiler Ticket expired in late January 2024. Currently in storage awaiting Overhaul.
| Maker | Andrew Barclay & Co. |
| Year | 1918 |
| Works number | 1431 |
| Type | 0-4-0WT |
| Driving wheel diameter | 2′ 0″ |
| Trailing wheel diameter | nil |
| Coupled wheelbase | 3′ 11 1/4″ |
| Total wheelbase | 3′ 11 1/4″ |
| Cylinder size (bore/stroke) | 6 7/8 x 10 3/4″ |
| Heating surface | 130 sq. ft. |
| Working pressure | 160 psi |
| Tractive effort @ 85% BP | 3290 lbs |
| Weight | 8 tons |
| Length over buffers | 15′ 6″ |
