Komatsu and General Motors plan to begin testing of a 930E mining truck powered by HYDROTEC fuel cells at Komatsu’s Arizona proving ground in the mid-2020s.

When it comes time to select a surface mine’s primary haulage method, the main event has always been the battle between flexibility and operating efficiency. Truck/shovel haulage remains the leading contender from the perspective of system flexibility, while in-pit crushing and conveying (IPCC) in its various forms – fixed, semi-fixed, semi-mobile or fully mobile – holds the edge in overall efficiency, according to most studies.

However, the mining industry has always been interested in larger-capacity mobile loading and haulage equipment and demand for bigger haulers has largely maintained its momentum despite occasional slowdowns due to market fluctuations, the global pandemic and other factors. Recent sales announcements from the leading haul-truck manufacturers highlight major orders for large and ultra-class (320-400 ton) electric-drive, rigid-body haulers, underscoring the industry’s need to move more material and the role that electrified, autonomous truck haulage is expected to fill in the future.

For example, last August BHP, Caterpillar and Cat dealer Finning announced an agreement to replace BHP’s entire haul truck fleet at the huge Escondida mine in the Antofagasta Region, northern Chile. The agreement is part of a strategic equipment renewal process developed by Escondida, and will include new 410-ton-payload Caterpillar 798 AC electric drive trucks, which were due to start arriving at the mine in the second half of 2023, with delivery of the remaining trucks to extend over the next 10 years as the three companies work to replace one of the largest fleets in the industry, currently comprising more than 160 haul trucks.

Just a few months later, Barrick’s Nevada Gold Mines (NGM) announced it had signed a multi-year agreement with Komatsu to deliver 62 930E-5 haul trucks between 2023 and 2025. The new trucks will work at two Nevada mines: 40 will be deployed to the Carlin Complex and 22 will be at the Cortez site. And earlier this year, Komatsu reported that more than 700 of its mining trucks were running on its FrontRunner Autonomous Haulage System worldwide, including more than 100 of its 400-ton-capacity 980E-AT models.

Among the less-clear factors associated with the transition towards newer and increasingly autonomous truck fleets is how many of those trucks will wind up being purely diesel powered versus alternative systems such as battery electric, hydrogen or some form of hybrid technology. Mining-class truck and engine manufacturers are hedging their bets by pairing up with companies that can offer experience and resources applicable to development of nontraditional offroad power systems.

Liebherr, recognizing that diesel power will remain a long-term solution for many mining customers, has been integrating its D98XX series diesel engines into its trucks and excavators in new markets globally, both as original equipment and as refits. The company also is exploring other power sources, including a prototype battery-powered truck, shown here, that was developed in partnership with Australian miner Fortescue.

For instance, in December 2023, General Motors and Komatsu announced that they plan to jointly co-develop a hydrogen fuel cell power module for Komatsu’s 930E electric drive mining truck. The two companies noted that hydrogen fuel cells are light and quick to refuel – properties that make them a prime candidate for electrifying applications traditionally powered by diesel engines. Hydrogen, according to GM, provides an effective method to package large quantities of energy onboard the vehicle, without compromising payload carrying capacity, and in additional, provide a zero tailpipe emissions solution for vehicles with extreme hauling requirements, like the Komatsu 930E mining truck, with its nominal payload of 320 tons. These vehicles typically operate at a single mine throughout their life, which simplifies the challenges of sizing and deploying an effective hydrogen refueling infrastructure to service the vehicle fleet.

GM and Komatsu intend to test the first prototype HYDROTEC-powered mining vehicle in the mid-2020s at Komatsu’s Arizona Proving Grounds (AZPG) research and development facility. This vehicle will be powered by over 2 megawatts of HYDROTEC power cubes.

And, as we reported in April, engine builder Cummins recently commissioned a diesel hybrid truck in partnership with Chinese manufacturer North Hauler JSC. The hybrid NHL NTH260, a 220-ton payload mining truck, was sent to the Baogang Baiyun iron ore mine to begin field testing. Cummins said its optimized hybrid system allows the truck engine to be downsized from the previous 2,500-hp QSK60 to a 2,000-hp, two-stage QSK50.

Meanwhile, Hitachi Energy and BluVein, an Australian/Swedish battery-electric technology joint venture, signed a memorandum of understanding to accelerate the electrification of heavy-haul mining fleets, aimed at leveraging the two companies’ electronics expertise to provide charging technology that can deliver electricity to haul trucks of up to 400 mt.

While haulage fleet electrification is obviously a distant but distinct industry goal among both suppliers and mine operators, that doesn’t mean that investment in diesel-based technology is fading. Caterpillar is reportedly planning to spend about $725 million by the end of 2027 to expand its Large Engine Center in Lafayette, Indiana, USA, where it builds the C175, 3500 and 3600 engine series. Liebherr, while currently involved in an agreement with Fortescue Metals Group to supply mining haul trucks integrating zero emission power system technologies being developed by Fortescue Future Industries (FFI) and Williams Advanced Engineering (WAE), also has in the past few years begun integrating its D98XX series diesels into its trucks and excavators in new markets globally, both as original equipment and as refits.

As the company notes, electrification will not be an option for every one of its mining customers, and it’s confident that future generations of internal combustion engines can be adapted to work with renewable fuel sources such as ammonia, methanol, and hydrogen. Overall, it invested about €634 million ($674 million) in research & development last year, mostly for new products in the areas of alternative drives, digitalization and autonomy. But it’s also taking steps to ensure that its ICE engines offer long-term value from improved flexibility, economy, reliability and less environmental impact in mining applications.

“The D98 series was developed as a platform concept,” explained Steffan Apel, key account manager for Liebherr Components. The company notes that the D98 platform allows multiple payload classes of Liebherr equipment to be served by one engine. The 12-cylinder D9812 can be used in the company’s R 9400, R 9600 and R 9800 excavators as well as in its T 264 haul truck, while the 16-cylinder version is compatible with the T 274 and T 284 truck models.

Over the past year or so, Liebherr also reported on success of its LI3 fuel Injector system, specifically developed for large diesel applications such as its 98XX series in mining and other industrial segments. According to the company, injectors from the LI3 product platform have lasted 20,000 hours in a field endurance test without any difficulties. This corresponds to an increase of 25% compared with an expected service life of 15,000 hours. The results, said Liebherr, confirm that use of LI3 injectors offers notable benefits including longer maintenance intervals, which lead to lower maintenance costs. Less wear with an above-average service life also ensures stable engine operation and reduces the likelihood of damage or warranty claims.

In addition, the company said that compared to reference injectors, the Liebherr injectors exhibited minimal cavitation effects such as premature wear, reducing the risk of nozzle rupture and associated engine damage and maintaining the engine’s emissions control performance.