The London, Midland and Scottish Railway (LMS) Royal Scot Class is a class of 4-6-0 express passenger locomotive introduced in 1927. Originally having parallel boilers, all members were later rebuilt with tapered type 2A boilers, and were in effect two classes.Built 1927-35. Designed by Sir Henry Fowler - Rebuilt by Stanier. Total Number Built 71 - Total to BR 71. Introduced 1927. Fowler and North British Locomotive Co. design with parallel boiler Classification 6P.Rebuilt to Stanier design with taper boiler (2A type), new cylinders and double chimney during 1943-55.