TINSLEY MPD (coded 41A to May 1973, then TI under TOPS) was a major purpose-built diesel depot in north-east Sheffield near the city’s border with Rotherham. It was part of a plan by British Railways to modernise and rationalise rail operations, being built in coordination with the expansive Tinsley Marshalling Yard that was designed to handle wagonload freight in the area.
The Tinsley site was chosen because it offered access to and from all directions, being situated on the Sheffield District Railway (SDR) with connections to the former Midland Railway and Great Central Railway routes. The only problem was that the SDR ran from Treeton to Brightside via a summit at Tinsley Wood Tunnel, where the line skirted around a large hill. Building the new marshalling yard and sidings meant excavating this hill area by some 50-100 feet (15-30 metres) to create a wide and level cutting into which the SDR line was diverted, although the depot was built at the higher level of the original SDR route.
Tinsley TMD formally opened in April 1964, replacing the area’s steam age sheds at Millhouses, Grimesthorpe, Darnall and Canklow, and soon became home to more than 200 main line diesels of Classes 20, 25, 31, 37, 47 plus around 75 shunters – including the three unique Class 13 ‘master and slave’ pairs converted from standard ‘08s’ to work Tinsley’s hump shunting yard.