The Silverton W class differed from the WAGR examples in having a skyline cowling running the length of the boiler and smokebox, Westinghouseair brakes, and an additional blow-down valve in the middle of the bottom of the boiler barrel.[1][2][3]
When the 48s class diesels arrived in 1961, the W class locomotives were retired, after only 10 years in service. They remained in store until disposed of in 1970, with three now preserved. The Pichi Richi Railway has a locomotive operating as W22, although it is actually W916 masquerading as W22, including some parts from the latter.[2][4]