The BR Standard Class 8 was a class of 4-6-2 Pacific steam locomotive designed by Robert Riddles for use by British Railways. Only the prototype was constructed, named Duke of Gloucester. Constructed at Crewe Works in 1954, the Duke, as it is popularly known, was a replacement for the destroyed LMS Princess Royal Class locomotive number 46202 Princess Anne, which was involved in the Harrow and Wealdstone rail disaster of 1952.^[2]

The Duke was based on the BR Standard Class 7 Britannia design. It incorporated three sets of modified Caprotti valve gear, relatively new to British locomotive engineering and more efficient than Walschaerts or Stephenson valve gear. The Duke was regarded as a failure by locomotive crews due to its poor steaming characteristics and its heavy fuel consumption. Trials undertaken by British Railways also returned negative feedback, reporting problems with the poor draughting of the locomotive which resulted in difficulty adhering to the timetables.