Railway electrification in Australia

Electrification of Australian railways began with the Melbourne and Sydney suburban lines. Melbourne suburban lines were electrified from 1919 using 1.5 kV DC. Sydney suburban lines were electrified from 1926 using the same system.

Later Australian systems used 25 kV AC electrification, which had been introduced in the 1950s in France, and by the 1980s become the international standard. Hence they differed from earlier systems, although as each suburban system is centred on a main city and are not interconnected this is not a problem. Later suburban systems were Brisbane from 1979, Perth from 1992 and Adelaide from 2014. There has also been extensive non-urban electrification in Queensland using 25 kV AC, mainly during the 1980s for coal routes.

Electrification of Melbourne routes was considered as far back as 1896, and in 1903 and 1907. In 1908 British engineer Charles Merz of Merz and McLellan recommended a 200 km system to St Kilda, Port Melbourne, Sandringham and Broadmeadows using 800V DC from a third rail. However his later 1912 report recommended 1500V DC from overhead catenaries, although at the time the system was not used anywhere in the world. This proposal was approved, and his firm was appointed to supervise the work. . Conversion to DC was by rotary converters, but Melbourne extensions in the 1920s from Croydon and Ringwood used mercury arc rectifiers.

Electrification of the Sydney network had been recommended by a Royal Commission in 1909, and in the Bradfield plan of 1915. John Bradfield recommended using 1500V DC; and this was supported by a conference of Railway Commissioners in 1922 who were anxious to avoid a repeat of the different track gauges used in each state. By this time the 1500V DC system was used on railways in England, the Netherlands, France and America. The same system was also recommended for the Brisbane suburban system in 1947-1950 although this proposal was abandoned in 1959.

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