class-10-shunter

The BR Class 10 was a series of 173 diesel-electric 0-6-0 shunting locomotives built at British Railways works at Doncaster, Darlington, Crewe, and Horwich between 1955 and 1962, mechanically identical to the concurrent Class 08 in their English Electric traction equipment and overall layout but fitted with the Blackstone ER6T diesel engine rather than the English Electric 6KT that powered the Class 08. The Blackstone engine — made by Blackstone & Co. of Stamford, Lincolnshire — proved less satisfactory in service than the English Electric unit, and the Class 10 locomotives were progressively converted to Class 08 specification by replacement of the Blackstone engine with the English Electric type through the 1960s and 1970s, effectively merging the Class 10 into the Class 08 fleet.

The existence of two engine types in what was otherwise the same locomotive was a consequence of the early BR diesel procurement strategy, in which parallel orders from different suppliers were placed to evaluate competing engine designs under the same operating conditions. The English Electric 6KT and the Blackstone ER6T produced similar power outputs and occupied the same engine compartment, allowing the comparison to be made on equal terms. The English Electric engine's superior reliability in service led to the progressive re-engining of the Class 10 fleet, which was a significant decision: it committed BR to the English Electric traction philosophy for its standard shunter fleet and effectively standardised the Class 08 as the universal BR heavy shunter.

One example retaining Class 10 identity, D3452, is preserved on a heritage railway.