Closed: still in operation
Length: 127km - 79mi (Gladstone to Paratoo) of 390km (242mi) total length
Built as a narrow gauge (3ft6in - 1067mm) line from Port Pirie to Gladstone in 1875, it was extended to Cockburn on the South Australia - New South Wales border in stages by 1888.
Because the South Australian Railways were not allowed to operate over the border into New South Wales, a private railway, the Silverton Tramway (which was called a "tramway" for legal reasons but it was a fully operating narrow gauge railway), was built to connect the line to the mines at Broken Hill. The SAR and Silverton Tramway simply swapped locos at Cockburn on the border.
The main purpose of the line was to transport the mineral ores from the mines at Broken Hill to the smelters and port at Port Pirie, a function it still performs today.
Several narrow gauge branch lines were added at Gladstone (to Wilmington), Peterborough (to Quorn and Terowie) and to mines between Paratoo and Cockburn. A broad gauge (5ft3in - 1600mm) line from Adelaide (the state capital) was extended to Gladstone in 1894. The narrow gauge line from Peterborough to Terowie was made dual gauge with the addition of broad gauge in 1970, providing a second broad gauge line to Adelaide.
In the 1902 working timetable a typical stopping freight service was allocated 3½ hours for the trip from Gladstone to Peterborough with about 50 minutes (in total) allowed for shunting, refuelling and crossing other services at the intermediate locations (Caltowie, Jamestown, Belalie North and Yongala).
During 1969-1970 the entire Port Pirie-Broken Hill line was converted to standard gauge (4ft8½in - 1435mm). The conversion closed or bypassed many of the locations along the narrow gauge line. Gladstone and Peterborough became triple gauge "break-of-gauge" locations. By 1990 all the connecting narrow and broad gauge lines were closed.
The line is now a vital part of the standard gauge Transcontinental railway from Sydney to Perth.
Only one passenger service still operates on the line, the Indian-Pacific which runs between Sydney and Perth via Adelaide. It runs non-stop between Broken Hill and Adelaide.