The Trans-Australian Railway railway line crosses the Nullarbor Plain from Kalgoorlie to Port Augusta. Construction of the line began in 1917, when two teams set out from Kalgoorlie in Western Australia and Port Augusta in South Australia, meeting in the centre of the Plain at Ooldea, an uninhabited area noted for a water supply. This original line suffered severe problems with track flexing and settling in the desert sands, and journeys across the Plain were slow and arduous. The line was entirely rebuilt in 1969, as part of a project to standardise the previously disparate rail gauges in the various states, and the first crossing of the Nullarbor on the new line reached Perth on 27 February 1970. The Indian Pacific is a regular passenger train crossing the Nullarbor from Perth to Sydney via Adelaide.