The Caledonian Railway had a large number of 0-4-4T tank locomotives built between 1884 and 1925, which were intended for local passenger traffic in Edinburgh and Glasgow. One of four chief engineers who procured these locomotives was John F. McIntosh. During his service, which lasted from 1895 to 1914, twelve members of class 92, twelve of class 104, ten of class 879 and 68 of class 439 were created.

Depending on where the individual classes were to be used, the driving wheel diameter differed significantly with 54 or 69 inches. For the sections laid underground, some locomotives had a condensation device, but this apparently could not always retain all of the steam. Pickersgill introduced the class 431 in 1922, which was based directly on the 439 and was used as a banker locomotive. The LMS also had its own version of the 439 built from 1925 onwards. A large number of McIntosh's 0-4-4Ts also survived into the British Railways era.