GWR 1500 / 1600 Class

The GWR 1500 and 1600 Classes were two related series of small outside-cylinder 0-6-0 pannier tank locomotives designed under the superintendency of F.W. Hawksworth and introduced in 1949, representing the final pannier tank designs produced under Great Western Railway tradition before nationalisation transformed British railway locomotive policy. Though technically introduced under British Railways, both classes were designed to GWR practice and are firmly part of the GWR locomotive heritage.

The 1500 Class (ten locomotives, Nos. 1500–1509) was an unusual design for the GWR tradition: outside cylinders driving the centre axle rather than the leading axle, short wheelbase for tight-curve working, and outside Walschaerts valve gear — giving the 1500 a distinctive and somewhat aggressive appearance quite unlike the typical GWR pannier tank. It was designed specifically for light shunting and trip working in industrial sidings and dock areas where small overall dimensions and outside-cylinder accessibility were important. The short wheelbase enabled it to negotiate curves that excluded most conventional 0-6-0 tank engines.

The 1600 Class (seventy locomotives, Nos. 1600–1669) was a more conventional small pannier tank based on the earlier 1400 Class auto-trailer tank but with minor modifications suited to branch freight and light goods working rather than auto-train passenger service. The 1600 retained the orthodox inside-cylinder layout and the characteristic GWR pannier tank profile.

Both classes gave service into the late 1950s and early 1960s before withdrawal as BR's diesel shunter fleet expanded. Several examples of both classes are preserved on heritage railways, making the 1500 and 1600 well-represented in the GWR pannier tank heritage collection alongside the much more numerous 5700 Class.