Rio Tinto will buy 150 driverless trucks from Japanese firm Komatsu Limited in the next four years under its Mine of the Future programme.

Tom Albanese and Kunio Noji, the companies' chief executives, signed in Tokyo a memorandum of understanding for the purchase and supply of the trucks.

Komatsu will begin delivery of the new trucks in 2012. Rio Tinto will use the driverless trucks in its Pilbara iron ore mines in Western Australia. The trucks could be controlled by remote from more than 1,500 kilometres away at Rio Tinto's operations centre in Perth.

The mining firm initially planned to just double its high-tech trucks to 10 units, but decided to hike the number to 150 to reduce cost and improve efficiency and health, safety and environmental performance as well.

Rio Tinto has been pilot-testing the Komatsu Autonomous Haulage System in Pilbara since December 2008.

"Autonomous haulage is an important component in our Mine of the Future programme. These 150 new trucks will work with our pioneering operations centre that integrates and manages the logistics of 14 mines, three ports and two railways. These technologies are revolutionising the way large-scale mining is done, creating attractive hi-tech jobs, and helping us to improve safety and environmental performance and reduce carbon emissions," Mr Albanese said in a statement.

Another component of the programme is the deployment of more automated drills in Pilbara and at coal and copper mines.

At its coal operations in Mozambique, Rio Tinto is considering transporting the resource from Tete using the Zambebi River. Rio Tinto Coal Mozambique Chief Executive Eric Finlayson said the river-based solution is more efficient that transporting the coal through the Nacala railroad system.

He explained the distance from Tete to the port would cover only 500 km if transported through the river while it would cover 900 km if moved by rail.

"Coal resources of billions of tons are being developed by Rio Tinto and by Vale, amongst other companies, and the railroad from Moatize to Beira is the only operational facility for transporting the coal and massive investment is needed in infrastructure to achieve significant levels of production," the Mozambique press quoted Mr Finlayson.