Under the agreements, traditional trucks will be converted to autonomous vehicles, with a total of 29 Komatsu haul trucks to be retrofitted with autonomous haulage system (AHS) technology starting next year.
By mid-2019, the company will be able to run the Brockman 4 operation entirely in AHS mode once fully deployed.
In addition, the company plans to retrofit 19 Caterpillar haul trucks at the Marandoo mine starting mid-2018 for completion by the end of 2019.
Rio Tinto iron ore chief executive Chris Salisbury said: “Rapid advances in technology are continuing to revolutionise the way large-scale mining is undertaken across the globe.
“The expansion of our autonomous fleet via retrofitting helps to improve safety, unlocks significant productivity gains, and continues to cement Rio Tinto as an industry leader in automation and innovation.
“We are studying future additions to our autonomous fleet in the Pilbara, based on value, to help deliver our share of $5bn of additional free cash-flow for the company by 2021.”
Once the projects with Komatsu and Caterpillar are complete, Rio Tinto will have more than 130 autonomous trucks, which is approximately 30% of its fleet.
Through the automation drive, the company aims to improve productivity and efficiencies across its operations in the Pilbara.
Under the AHS technology, trucks are operated by a supervisory system and a central controller, eliminating the need for a driver.
Using pre-defined GPS courses, AHS automatically navigates haul roads and intersections and has information regarding actual locations, speeds and directions of all vehicles.
In September, the company ran its first fully autonomous heavy haul train.