The six examples of this class were designed by Patrick Stirling for the GSWR and were built by Kilmarnock Locomotive Works between 1864 and 1866, to replace earlier 0-4-0 goods locomotives inherited by the railway. They were numbered 52-57-. The members of the class were fitted with weather boards, later replaced by Stirling cabs. The safety valves over the firebox were later replaced by those of Ramsbottom design over the centre of the boiler following a boiler explosion at Springhill in 1876. The class was later perpetuated by Stirling’s brother James Stirling (1835–1917) in his 65 class goods locomotives.