W class trams were introduced to Melbourne in 1923 as a new standard design. They had a dual bogie layout and were characterised by a substantially timber frame supplanted by a steel under frame, a simple rugged design, and fine craftsmanship (particularly the older models). The W Class was the mainstay of Melbourne's tramways system for 60 years. A total of 748 trams of all variants were built. The W class is an icon to the city and recognised by the National Trust of Australia.