When the Commonwealth of Australia was formed by the six Australian colonies in 1901, Perth, the capital of Western Australia was isolated from the remaining states by thousands of miles of desert, and only sea transporation was practicable, with adverse cost and time implications.
After a two-year survey, a route from Port Augusta (the terminus of an existing line in South Australia) via Tarcoola to the gold-mining center at Kalgoorlie was proposed.
The line was to be standard gauge throughout, despite the fact that the states at each end ran their own train systems on narrow gauge.
The relevant legislation was passed in December 1911, and work commenced in September 1912. by the end of 1915, working eastwards from Kalgoorlie and westwards from Port Augusta, the ends of the line were just over 600 miles apart, and they met on 17th October 1917.
On inauguration the passenger service was known as the Great Western Express - between Kalgoorlie and Port Augusta it was known as the Trans-Australian, and from February 1970 the entire route because known as the Indian Pacific.
Where it cross the Nullarbor Plains, the line includes a 478km section of track which is dead straight - the world's longest section of straight track.
This scenario doesn't follow the Indian Pacific faithfully, as from Sydney it takes a different line, down to Melbourne, before heading back up north past Adelaide to Port Pirie, then on to the west.
This scenario is the second Snowdonia scenario (after the Neuhauser Bockerlbahn scenario) to be designed by someone other than Tony Boydell - this scenario was was designed by Matthew Dunstan