LMS Royal Scot Class

The Royal Scot Class was a class of 4-6-0 express passenger locomotives introduced in 1927 for the London, Midland and Scottish Railway. Until the mid-1920s the LMS had followed the Midland Railway's small engine policy and had no locomotive powerful enough for its West Coast expresses. After a one month loan of the Great Western Castle class engine Launceston Castle showed what a large 4-6-0 could do, the company cancelled a planned compound Pacific and ordered fifty three-cylinder engines from the North British Locomotive Company of Glasgow, with a further twenty built at Derby Works. The Derby drawing office and North British staff designed the class together, using drawings of the Southern Railway Lord Nelson Class for the firebox. The engines were first named after regiments of the British Army and historical LNWR locomotives. They were built with parallel boilers, and all were later rebuilt with tapered 2A boilers, so that the class was in effect two classes.