The WAGR O Class was a 2-8-0

2-8-0

Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...

 type steam locomotive built for the Western Australian Government Railways

Western Australian Government Railways

Western Australian Government Railways was most common name of the Western Australian government rail transport authority from 1890 to 1976. It is, in its current form, known as the Public Transport Authority of Western Australia....

 in 1896. They were tender locomotives, but also featured short boiler side tanks for additional water storage useful in the long distance required by operation in Western Australia's country lines. The type shared much in common with the N Class

WAGR N Class

The WAGR N Class tank engines were 4-4-4T type steam locomotives operated by the Western Australian Government Railways. The type was introduced in 1896 and initially served in both Perth and Kalgoorlie, but traffic was lost to Kalgoorlie within a few years and the type was withdrawn to Perth...

suburban tank engines, also of the WAGR, and 10 O class were rebuilt as N class locomotives in 1907/08. The last examples of the O class was withdrawn from service in 1962.