The first railway in colonial South Australia was a line from the port of Goolwa on the River Murray to an ocean harbour at Port Elliot, which first operated in December 1853, before its completion in May 1854.
During the following seven decades construction continued, by stops and starts, often to encourage agricultural development or to ameliorate unemployment. Very little additional trackage was built from the 1920s onwards. In 1966, the total was , comprising of and of .
Following almost total closure of regional lines in South Australia in the last decades of the twentieth century, today the state's rail network comprises standard gauge links to other states, broad gauge suburban railways in Adelaide, a narrow-gauge gypsum haulage line on the Eyre Peninsula, and both copper–gold concentrate and coal on the standard-gauge line in the Adelaide–Darwin rail corridor north of Tarcoola.
History
The first railway in colonial South Australia was the horse-drawn tramway from Goolwa to Port Elliot opened in 1854, providing a rail link from the port of Goolwa on the Murray River to an ocean harbour at Port Elliot. It was later extended to a safer harbour at Victor Harbor. This line was used to move freight between the shallow-draft vessels navigating the Murray, and coastal and ocean-going vessels, without either having to traverse the narrow and shallow mouth of the river with unpredictable currents.
The first of the Railways in Adelaide was built in 1856 between the city and the port. The Adelaide railways were all built as broad gauge of . Gradually, a network of lines spread out from Adelaide. These were initially built to carry ore, particularly copper, then later freight from the Murray River, and grain from the broadacre lands. In the first half of the 20th century, most of these lines carried passengers as well as freight.
The main line to Melbourne was opened after a bridge was built at Murray Bridge in 1886. It was the first railway line between colony capitals to not have a break-of-gauge. It was also the last of these to be converted to standard gauge in 1995.
Gauge
In 1847, the Parliament of South Australia passed an act confirming adoption of the newly termed "standard gauge" (originally "Stephenson gauge") of – the first Australian colony to do so. In 1848 the Colonial Secretary in London, Lord Grey, recommended all the Australian colonies adopt that gauge. However, the company building the first railway in New South Wales decided to adopt the "Irish" broad gauge gauge of . Soon afterwards, Victoria and South Australia ordered locomotives and rolling stock to the wider gauge. New South Wales changed back to preferring standard gauge, but it was too late for Victoria and South Australia to change yet again. Thus began Australia's "mixed gauge muddle", which persists to this day.
The first main line railway in Adelaide was built in 1856 between the city and the port. The main line to Melbourne was opened after a bridge was built at Murray Bridge in 1886. It was the first railway line between Australian capital cities not to have a break-of-gauge – but it was to be 109 years before it was converted to standard gauge in 1995, the last inter-capital line to be converted.
Narrow gauge
Influenced by Queensland Railways' successful adoption of the narrow gauge for cost reasons (opened 1865), and influenced by the advocacy of people such as Abraham Fitzgibbon, South Australia changed the gauge of the Port Wakefield line in the middle of construction. The Port Wakefield line, opened 1870, was originally horse drawn.
Because the narrow gauge lines of started out as isolated lines from independent ports at Port Wakefield, Port Pirie, Port Augusta, Port Lincoln, Port Broughton, Beachport, Kingston SE and Wallaroo, and a private tramway from Whyalla, the problems of the nascent break of gauge was not immediately apparent. When the broad and narrow systems finally met at Hamley Bridge, Terowie, Wolseley and Mount Gambier endless complaints started. There may have been even more breaks of gauge, as the original bridge at Murray Bridge was designed for narrow gauge.
The horse-drawn narrow gauge Port Broughton railway line on the Yorke Peninsula was never connected to the main system.
The lines on the Eyre Peninsula Railway and throughout the mid-north were built to narrow gauge. Once the narrow gauge from Port Pirie to Broken Hill was converted to standard gauge, the narrow gauge from Terowie was converted to broad gauge to Peterborough. Peterborough became the change of gauge station for Broken Hill Adelaide express. The narrow gauge line was retained north from Peterborough to Quorn.