Built in 1951 for Commonwealth Railways by Clyde Engineering under license from General Motors, the eleven members of the GM1 class were ordered primarily to dieselise operations, following on from overseas examples. The GM1 Class were based on the US EMD F7 model, with a number of alterations to ensure that they fitted the local loading gauge and axle load restrictions. Part of the design for the first eleven locomotives was to have an unpowered centre bogie – making the wheel arrangement A1A-A1A. All eleven members of the class were delivered by July 1952, displacing most mainline steam on the Commonwealth Railway network.

Text courtesy of Trackside