[1][2][3] The resultant locomotive included many proprietary boiler and ancillary fittings, as well as parts interchange ability.

[4] The running gear was based heavily on Beyer, Peacock & Co's Standard Light Garratt, which was built for the South Australian Railways as its 400 class.

Although they have a well-deserved reputation for their reliability, like any new class the W locos suffered some minor teething problems, including ashpan failures, and leaks in and around the foundation ring.

At one point, no fewer than 34 of the class were in Midland Railway Workshops or regional depots for stay repair.

The light axle load of the W class along with their relative youth resulted in them being sought after by tourist operators, both in Western Australia and interstate with 15 preserved.

Until 2006, Hotham Valley Railway's Ws operated services on the Brookfield Rail network, but today they are confined to its own heritage line.