 These small shunters remained in long service under the LMS (who gave all Neilson saddle locomotives the power class 0F, shared by many other types) and British Railways, with the last of the class withdrawn in 1962.The two classes, sometimes referred to by the generic term "pugs", were mainly used as works shunters in the area around Glasgow, Scotland, often running with home-made tenders to improve their small coal capacity.Like most 0-4-0 tanks of the period they had outside cylinders and inside slide valves driven by Stephenson valve gear.