The Trans-Australian Railway, opened in 1917, runs from Port Augusta in South Australia to Kalgoorlie in Western Australia, crossing the Nullarbor Plain in the process. As the only rail freight corridor between Western Australia and the eastern states, the line is strategically important. The railway includes the world's longest section of completely straight track. The inaugural passenger train service was known as the Great Western Express; later, it became the Trans-Australian. , two passenger services use the line, both of them experiential tourism services: the Indian Pacific for the entire length of the railway, and The Ghan between Port Augusta and Tarcoola, where it leaves the line to proceed north to Darwin. History In 1901, the six Australian colonies federated to form the Commonwealth of Australia. At that time, Perth, the capital of Western Australia, was isolated from the remaining Australian states by thousands of miles of desert terrain and the only practicable method of transport was by sea. The voyage across the notoriously rough Great Australian Bight was time-consuming, inconvenient and often uncomfortable. One of the inducements held out to Western Australians to join the new federation was the promise of a federally funded railway line linking Western Australia with the rest of the continent. In 1907, legislation was passed, allowing for the route to be surveyed. The survey, completed in 1909, endorsed a route from Port Augusta (the existing railhead at the head of Spencer Gulf in South Australia's wheatfields) via Tarcoola to the gold mining centre of Kalgoorlie in Western Australia, a distance of . The line was to be built to the standard gauge of , even though the state railway systems at both ends were narrow gauge at the time. Its cost was estimated at £4,045,000. Legislation authorising the construction was passed in December 1911 by the Fisher Commonwealth Government. Work commenced in September 1912 in Port Augusta. Work proceeded eastwards from Kalgoorlie and westwards from Port Augusta through the years of the First World War. Tracklaying proceeded briskly when materials were available. At its peak, up to of track were laid each day, and were completed in one calendar year – both Australian tracklaying records. By 1915, the two ends of the line were just over apart with materials being delivered daily. Construction progressed steadily as the line was extended through mainly dry and desolate regions until the two halves of the line met