The Mid Sodor Railway was a narrow gauge railway which operated from January 1840 to December 1987. Some parts of the line were late rebuilt for the Arlesdale Railway, while a majority of the route has been reopened as the Mid-Sodor Heritage Railway.
Over its near-sixty-year existence, the MSR utilised a number of engines, most of which remain unrecorded. Four engines are mentioned in the books, and these are described below.
In the story Bulldog a 'fifth' engine may be seen asleep in the engine shed. Comparison of this engine with the 'pumping engine' pictured in the previous story might suggest that the two are one and the same engine (Stanley) – the top lamp bracket mounting is the same for both engines, for example. However, this is pure conjecture, as the Rev. W.V. Awdry makes no reference to it.
- Main Article: Duke
Duke worked on the Mid Sodor Railway until its closure. He now works on the Skarloey Railway.
Stanley was engine number 2 on the Mid Sodor Railway, and originally came from America. He had a tendency to ride roughly on the rails. He was also arrogant and careless, believing that it didn't matter if he came off the track occasionally. However, this attitude resulted in his being converted into a pumping engine. He last worked at the Cas-ny-Hawin mine, where a breakdown resulted in the mine flooding and the closure of the railway.
He appeared in a single illustration in Duke the Lost Engine, as a pumping engine at the back of the engine shed. The engine is only known as 'No. 2' in that book; his name not being revealed by the Rev. Awdry until the publication of The Island of Sodor: Its People, History and Railways.
Stanley is based on a Baldwin Locomotive Works 4-6-0 World War I military engine sold after the war to the Welsh Highland Railway where it ran as No. 590. The engine was reputed to ride roughly and was broken up for scrap in 1942.
- Main Article: Sir Handel
Falcon was a young engine who paid more attention to the view than where he was going. On closure of the MSR, he was bought by the Skarloey Railway where he works, renamed, as "Sir Handel".
- Main Article: Peter Sam
Stuart is also based on a Corris Railway locomotive, No.4, which was purchased by the Talyllyn Railway where he runs as "Edward Thomas".
The Mid Sodor Railway can claim many sources of inspiration. Most obviously, it takes inspiration from the Corris Railway and the Ffestiniog Railway. Some of the architecture, locomotives and rolling stock are clearly based on the former line. This is most notable in the case of Falcon and Stuart, which are based on the Corris Railway's number 3 and 4 respectively.
The Ffestiniog Railway's influence is most obvious in the character of Duke, an engine based on the Ffestiniog locomotive Prince; some of the rolling stock is also Ffestiniog-inspired. Like the Ffestiniog, the MSR is designed as a narrow gauge main line. In the history of the MSR, Awdry mentions Ffestiniog engineer James Spooner's involvement.
Readers have also identified elements of the Welsh Highland Railway (the character Stanley), the Snailbeach District Railways (the engine shed) and Owd Ratty (the original Template:3ft gauge Ravenglass & Eskdale Railway), among others, used by Gunvor & Peter Edwards the artists who illustrated Duke the Lost Engine.
In Model Form
Rev. W. Awdry owned a model railway based on the MSR which included engines called Albert (No. 5), Jim (No. 6), Tim (No. 7), and Jerry, as well as an unnamed tank engine working at the mines. See also the relevant section in Unfeatured Characters for more information.