New South Wales Sputnik suburban carriage stock

Between 1956 and 1960, 40 power cars and 40 trailer cars were built by Commonwealth Engineering for the New South Wales Government Railways. Broadly similar to the Tulloch built carriages, built earlier in the 1950s, they differed in having motors on all four (as opposed to two) bogies and power operated doors. They operated as eight carriage sets and were targeted as S sets, gaining the nickname Sputniks after the Russian satellite that was launched at the same time as their entry into service.[3][4][5]

Ostensibly built to provide rolling stock for the newly electrified Parramatta to Penrith section of the Main Western line, they operated across the Sydney suburban network.[5]

Following the delivery of the Tulloch double deck trailers from 1964, these replaced the original trailers in the S sets. The displaced carriages had their power door equipment disconnected, were fitted with manually operated door equipment and pooled with the Suburban and Tulloch stock. These were renumbered upwards by 50, eg T4701 became T4751.[3][4][5]

Originally painted indian red, from 1973 they were repainted in the Public Transport Commission blue and white livery before the livery reverted to indian red in 1976. The interiors were painted in two-tone green.[5]

Overhauls of the stock continued up until 1988, with some receiving sliding aluminum Beclawat windows to alleviate rust problems. Most of the trailer cars remained in service until the end of single deck operation in January 1992.[3] The last power cars were withdrawn in November 1993.[5] Several have been preserved.[6]