Rio Tinto said Dec. 28 that it has successfully deployed the AutoHaul program across its iron ore operations in Western Australia's Pilbara region, establishing the world's largest robot and automated heavy-haul, long distance rail network.

The miner operates about 200 locomotives on more than 1,700 kilometers of track in the Pilbara region, transporting ore from 16 mines to four port terminals.

Since completing the first loaded run in July, the company increased the number of autonomous journeys across the operations, with over 1 million kilometers.

"It's been a challenging journey to automate a rail network of this size and scale in a remote location like the Pilbara, but early results indicate significant potential to improve productivity, providing increased system flexibility and reducing bottlenecks," said Ivan Vella, Rio Tinto Iron Ore managing director Rail, Port & Core Services.

The US$940 million project reached the near-completion stage around four years behind its original schedule of early 2015 and 81% over budget. The original budget for the project was A$517 million, according to a same-day report by The Australian Financial Review.

The company said it will continue to work closely with drivers in the coming months and does not expect to make any redundancies in 2019 due to the deployment of the autonomous rail project.

Rio Tinto said previously that the project will probably affect only 10% train driver jobs, as the company still needs people to supervise the trains and drive on some portions of its rail network, and would also look into reskilling and redeploying workers displaced by technology.