'Pug' locomotives are small steam locomotives which were produced for light shunting and industrial work, often on dockyards and factory sites, such as steelworks, collieries, etc. The Pugs are named after a common term in Scotland for a small industrial shunting locomotive – typically an 0-4-0tank. ‘Pug’ was a dialect word meaning ‘monkey’ inferring an ugly appearance. Another suggestion is that the locomotive type is named after the small sturdy 'Pug' dog, an ancient and well known breed with a snub nose, wrinkled face, and squarish body. Many were saddle tanks, with the water tank sitting on top of the boiler like a saddle. Whilst most commonly used for small shunting engines, on some railways the term 'Pug' was used for all tank engines. For example, the very large Glasgow and South Western Railway 540 Class 4-6-4T express passenger locomotives were known to their enginemen as the 'Big Pugs'.
Examples
Many locomotive manufacturers produced Pug type locomotives mainly for shunting work and for use on industrial sites with tight curves for which 0-6-0 locomotives were less well suited, despite their greater tractive effort capabilities. The Lancashire and Yorkshire RailwayL&YR Class 21 were nicknamed 'Pugs' and the Caledonian Railway built a class of 0-4-0 Pugs. The North British Railway had a class of 38 locomotives designated NBR G Class which were commonly nicknamed 'Pugs' by staff. A typical example is illustrated by the makers plate of number 1821, an 0-4-0 steam locomotive ordered from Andrew Barclay Sons & Co. on 12/02/1924 by the Caprington and Auchlochan Collieries Ltd. The locomotive was delivered to the customer in 1925 and mainly worked at Mauchline Colliery number 7 pit in Ayrshire, before ending its days at the nearby Barony Colliery. Pugs were used Worldwide, such as the metre gaugeBlack Hawthorn, an 0-4-0ST locomotive that was imported into India in 1873 for an irrigation project and shunted at Ajmer for several years in the later part of its working life. It can now be seen plinthed outside the Ajmer works.
In fiction
In The Railway Series books by the Reverend W. Awdry, a character called 'Pug' appears in the 12th book, The Eight Famous Engines. After problems of consistent accuracy of the drawings in the early books, later characters were based more closely on real locomotives. Although not explicitly identified by Awdry, the locomotive in the illustration by John T. Kenney, has been identified as most closely resembling a LMS Kitson 0-4-0ST.
