The GWR 0-6-0PT (Pannier Tank), is a type of steam locomotive built by the British Great Western Railway with the water tanks carried on both sides of the boiler, in the manner of panniers. They were used for local, suburban and branch line passenger and goods traffic, for shunting duties, and as banker engines on inclines. The early examples, such as the 1901 and 2021 classes, were rebuilt from saddle or side tanks when the locos received a Belpaire firebox – this type of firebox has a square top and is incompatible with a curved saddle tank. This process mostly took place during the tenure at Swindon Works of George Jackson Churchward. Only a very small number of saddle tank locomotives escaped rebuilding as panniers, notably the 1361 Class built new under Churchward in 1910, by which date a few of the 1813 Class had already been rebuilt as pannier tanks.
The GWR pannier tank locomotives were classified as follows:
Small engines (wheelbase under 15'), rebuilt from saddle or side tanks
93, 850, 1901 Classes · G. Armstrong/W'hampton 1874-95, 292 locos
2021, 2101 Classes · Dean/W'hampton 1897-1905, 140 locos
Small engines (wheelbase under 15'), built as pannier tanks from new
5400 Class · Collett/Swindon 1930, 25 locos
6400, 7400 Classes · Collett/Swindon 1932-50, 90 locos
1366 Class · Collett/Swindon 1934, six locos
1600 Class · Hawksworth/Swindon 1949-55, 80 locos
Large engines (wheelbase over 15'), rebuilt from saddle or side tanks
302 Class · J. Armstrong/W'hampton 1864-5, eight locos
1016 Class · G. Armstrong/W'hampton 1867-71, eight locos
1076 (Buffalo), 1134 Classes · J. Armstrong/Swindon 1870-1881, 266 locos
645, 1501 Classes · G. Armstrong/W'hampton 1872-81, 106 locos
119 Class · G. Armstrong/W'hampton (renewals after Gooch) 1878-83, 11 locos
322 Class · G. Armstrong/W'hampton (renewals after Beyer) 1878-85, six locos
1813 Class · Dean/Swindon 1882-4, 40 locos
1661 Class · Dean/Swindon 1886-7, 40 locos
655 Class · G. Armstrong/W'hampton 1892-7, 52 locos
1854 Class · Dean/Swindon 1890-95, 120 locos
2721 Class · Dean/Swindon 1897-1901, 80 locos
Large engines (wheelbase over 15'), built as pannier tanks from new
GWR 5700 Class · Collett/Swindon and outside firms 1929-50, 863 locos
GWR 9400 Class · Hawksworth/Swindon and outside firms 1947-56, 210 locos
Large boiler/short wheelbase
GWR 1500 Class · Hawksworth/Swindon 1949, 10 locos
In the Railway Series of children's books by the Rev. W. Awdry, the character Duck the Great Western Engine is based on a 5700 Class pannier tank.
No. 5775 is featured in the film The Railway Children in a brown livery, with the initials of the fictitious Great Northern and Southern Railway on the tank sides.
No. 6412 starred in the 1970s children's TV series The Flockton Flyer.
