In addition to improving safety and efficiency, the change could reduce the mine’s idle time by 10,000 hours annually
By Steve Fiscor, Editor-in-Chief
Freeport-McMoRan and Caterpillar recently announced that the two companies are collaborating to convert the mining company’s fleet of 33 Cat 793 haul trucks at its Bagdad mine in Arizona to an autonomous haulage system (AHS).
“We look forward to partnering with Caterpillar to become the first U.S. copper mine to implement a fully autonomous haulage system, and we are excited about the numerous benefits it will bring to our Bagdad operation and employees,” said Kathleen Quirk, president, Freeport-McMoRan. “The three-year conversion project is expected to improve safety, optimize our fleet, reduce GHG emissions through reduced idle time and position us to capitalize on future technological advancements in electrification.”
Cat recently celebrated the 10th anniversary of its MineStar Command for hauling platform, and the company has more than 620 haul trucks operating autonomously around the world. These trucks have hauled more than 6.3 billion metric tons of material and traveled more than 143 million miles without causing any reported injuries.
“We are pleased to collaborate with Freeport as they transition to fully autonomous haulage at Bagdad,” said Denise Johnson, group president of Caterpillar Resource Industries. “The Cat 793 haul truck remains Caterpillar’s most popular autonomous truck model and is well proven to enhance safety, increase productivity, and reduce idle time across multiple operations, including copper mines. Additionally, Caterpillar continues to work with Freeport, and other mining companies, to introduce new electrification technologies supporting their sustainability objectives.”
Located approximately 100 miles northwest of Phoenix, the Bagdad mine is a porphyry copper deposit containing both sulphide and oxide mineralization. It consists of an 85,000 ton-per-day concentrator that produces copper and molybdenum concentrate and a solvent extraction/electrowinning (SX/EW) plant that produces 9 million lb/y of copper. It is one of the oldest, continuously operating SX/EW plants in the world.
Meeting Sustainability Objectives
Freeport-McMoRan has active partnerships with Cat and Komatsu to advance zero-emissions mining trucks, supporting technologies and infrastructure. In mid-2023, the company decided to transition the haul truck fleet at the Bagdad mine to 100% autonomous over three years.
The first two years of the conversion project will be spent retrofitting the existing haul trucks with autonomous technology, installing new supporting equipment and infrastructure, and training its workforce to safely operate and service the new technology. During the third year, the autonomous trucks are expected to come online.
Manned trucks run 24/7, but often sit idle for, among other things, operator breaks, shift change, fatigue and coaching. Freeport’s preliminary estimates indicate that Bagdad will be able to reduce idle time by more than 10,000 hours per year.
Although full electrification of haul trucks on a large scale is still years in the future, autonomous haul truck technology is an important step toward electrification. Rather than waiting for electrification technology to be developed and attempting to embrace it all at once, by transitioning Bagdad now, Freeport believes they will be able to learn more about autonomous technology and how to leverage that technology before battery-operated haul trucks are introduced.
The Rationale Behind the Decision
The Bagdad mine has operated manned fleets very efficiently for many years. They had evaluated the use of AHS in the past but didn’t believe the economics would work. Today, both Cat and Komatsu have much more experience operating fleets and Freeport reconsidered.
“The efficiency of autonomous fleets historically hasn’t kept pace with, or hasn’t met the capability of our manned fleets,” said Justin Cross, vice president of operational improvement for Freeport-McMoRan. “The economic driver wasn’t there at the time and the economics just wouldn’t work out. The technology, however, has matured. The Bagdad mine was also dealing with some constraints as far as finding and retaining labor. That, coupled with the possibility of running battery-powered trucks in the future, brought the decision on AHS forward. The time was right, and we believe AHS will now be economically viable as a deployed haulage solution.”
Cross believes the transition will improve efficiency. “We are implementing AHS at a site that is positioned to grow,” he said. “Increasing the workforce to support manned haulage is not a viable option, and AHS minimizes that need.”
The use of electrically powered haulage, whether it’s batteries, overhead trolleys or both, is rather complex. “Power management with these systems will be incredibly important,” Cross said. “If you have a 500-ton truck running on empty, the operator has to decide whether to make one more run or recharge. What speed were we supposed to be traveling on that trolley line? Should I go to the shovel and get another load? Do I have enough power to make it to the crusher? AHS solves the problems associated with people making those decisions. If electrically powered haul trucks are our future reality, we knew we needed to get familiar with AHS.”
Freeport selected the Bagdad mine, not only because of the workforce challenges, but also because it was a mid-sized mine. “Bagdad has enough trucks to make this deployment make sense,” Cross said. “We thought about smaller mines, like Tyrone and Climax, but the truck fleets are not large enough. For a mine like Morenci, that would be a big leap to try and go from a manned fleet to autonomous at a complex like that.”
The mine plans to improve its current mesh network to support data transfer. “This will be dispatch on steroids,” Cross said. “Mesh networks are a little more expensive, but highly reliable, and we need 100% coverage all the time.”
Bagdad operates one deep pit with a long uphill haul to a crushing installation or multiple waste dumps. The cycle time for the haul trucks varies from 30 to 60 minutes. “Bagdad is the right size for the initial deployment, the technology is mature enough, and we want to learn about AHS,” Cross said.
Making the Leap
Komatsu and Cat have a great deal of experience running trucks autonomously, Cross explained, but Bagdad already had a Cat platform in place and the upgrade just made sense. “Bagdad runs a standard fleet of Cat 793 haul trucks,” Cross said. “We can readily apply the technology to our existing fleet.”
Bagdad has already started to retrofit the trucks, but it is not running any trucks autonomously yet. “We rebuild all of our trucks,” Cross said. “As the trucks go to the shop for a rebuild, we install the autonomous-ready packages and then rebuild them. The first autonomous truck will probably be running by the middle of 2025.”
Cross said they will integrate the autonomous trucks one at a time with the manned fleet. The fleet will operate mingled until the transition is complete. “We will be looking for the opportunity to make efficiency gains and learn more as we evaluate the conversion process,” Cross said.
Obviously, this is a huge change management process, but the people part has been a pretty good story, Cross explained. “We sat down with everyone and explained all of the different options that they can pursue. We have already started socializing some of the new jobs and what they would look like. One example would be pit builders. The pit has to be designed so that the trucks know the roads, and where the shovels are located constantly. That’s a job. There are a lot of instrument tech jobs, and we have been soliciting interest from folks.”
Bagdad has also asked the operators what they would like to do once the mine starts phasing out some of the haulage operator jobs. “We are not going autonomous on our support fleet,” Cross said. “Those operators that want to continue to drive a truck can drive water trucks and other small support equipment, like the Cat 777s, etc. Or, if they wanted to go to a different site to continue to drive trucks, Freeport would support that as well.
“We are bringing our people along with us,” Cross said. “A career path at Freeport will be available for them with new jobs coming online.”
Management will need some retraining as well. “Cat has a lot of expertise, and we have already sent some of our people to Australia and Canada to learn from those operations,” Cross said. “We’re working with sites that have already deployed autonomous, and we’re working with an OEM who has deployed multiple autonomous fleets. Our Cat dealer, Empire, has been a great partner in helping us move forward.”
Measuring Improvement
Both Komatsu and Cat have had a phenomenal decade plus safety record with autonomous haulage, Cross explained, with no lost-time accidents associated with haulage. “AHS uses a lot of safety-related barriers, and the system’s default is to essentially shut down before any potential collision or safety-related event,” he said. “Whether it’s fatigue or just the energy associated with the trucks, one of the more complex things to manage at our operations is safe powered haulage. We perceive a notable improvement in workplace safety as a result of autonomous deployment.” When it comes to powered haulage, the Bagdad mine has a respectable safety record, and they plan to maintain or improve that statistic.
Another area where Freeport could anticipate improvement is with haul truck maintenance. The autonomous trucks will run as designed most of the time. “We are also anticipating the fleet to run more consistently with better road conditions,” Cross said.
Bagdad’s truck fleet historically has run quite efficiently. “With optimization, we might be able to eliminate a truck or two over time, but the biggest benefit will be the efficiency gain from the manpower side,” Cross said. “Productivity and cycle times should improve. We will have no idling for operator breaks. We already combine shift change and refueling. There would be a degree of benefit on shift change, not waiting for the driver, but the trucks still have to be refueled.”
Cross said he will consider the transition a success when they see the efficiency gains that they anticipate. Success would also be achieved when Freeport is so confident with the technology that they would consider deploying it at other operations. “As far as how it fits into our future power management solution, we won’t know that for a while as it’s on a longer timeline,” Cross said. “If we can prove that autonomy is equal to or better than the efficiency of our manned fleets, that will be a success on our way to the power management solution.”
One source of pride for Cross and Bagdad General Manager Jeff Monteith is that the Bagdad team has realized that this could be a win-win for everyone. “We’re not making this transition to eliminate jobs,” Cross said. “Haulage operations are very difficult jobs, and the new jobs will be a change for the better. Everyone is a winner in this. Through the deployment of technology, we’re creating jobs that are better for people. They will get to learn and apply new skills.
“We’re reducing the input costs of running our operations, which extends their lives,” Cross said. “Automation can be used to serve business and the workforce. There is a lot of noise about displacement when it comes to AHS. Yes, we’re displacing workers, but they are not leaving the mine site. Many will move into upskilled positions.”