The S-class was a class of 18 trams built by Duncan & Fraser, Adelaide for the Melbourne, Brunswick & Coburg Tramways Trust (MBCTT).
All passed to the Melbourne & Metropolitan Tramways Board (MMTB) on 2 February 1920 when it took over the MBCTT, becoming the S-class[a] and renumbered 154-165.
[1][2][3] The other six were built to a slightly modified design, being delivered to the MMTB between 1920 and 1922.
[3][a] In 1941/42, 14 were rebuilt for one-man operation, seven for the isolated Footscray network and seven for all night services on the main network.
The Footscray cars were returned to crewed configuration in 1947.