Putting Power to Pedal 

E&MJ looks at new developments for mining engines and drivetrains

By Carly Leonida, European Editor

Engines and drivetrains are the unsung heroes of mine sites the world over. The prime movers behind the pedal of every truck and loader. But out of sight doesn’t mean out of mind.

While electric and battery-electric options are growing in popularity, their global population is still dwarfed by diesel-driven equivalents. In addition to expanding their portfolios with electrified, and even some hydrogen-powered technologies, OEMs are working hard to improve the efficiency of their diesel units, extending asset lifespans wherever possible and driving down total cost of ownership (TCO) as well as their carbon footprint.

In line with this, the past 12 months have seen a host of new facilities opened to better service key mining markets, as well as product announcements and research into new power sources. The following article summarizes some of these developments.

Cummins Master Rebuilds Come to Europe

In October 2023, Cummins opened a European Master Rebuild Centre for high horsepower engines in Krakow, Poland. This is the newest of 13 Cummins Master Rebuild Centers around the world, and the first of its kind in Europe.

The new 4,600 m² facility, which represents an investment of $10 million, provides remanufacturing capabilities for Cummins high horsepower engines with displacements of 19 to 78 liters in the 450 to 3,500 horsepower range, including QSK19, QSK38 and QSK60 models which are a staple in the mining industry.

Cummins said the facility will help it to meet growing demand across several sectors, including mining, marine and rail. Engines are subject to a six-stage remanufacturing process that sees them disassembled, cleaned, inspected, re-machined, reassembled with genuine Cummins parts and tested. As a result, the engine’s life is extended, and its performance is enhanced.

Rebuilt engines are increasingly becoming the first choice for mines that want reduced costs and greater engine uptime. Goran Galic, Aftermarket Strategic Accounts Director in Europe, spoke to E&MJ about this trend.

“Modern mining companies are looking to achieve the best possible cost-per-ton of material moved and to optimize the TCO for their fleets,” he said. “Opting for remanufactured engines helps to reduce the TCO and boost uptime, because the customer is getting a Cummins-certified engine, with the same warranty, performance and life expectancy as a brand-new engine, but at 75%-80% of the cost. That’s a significant saving, especially for operations which run large fleets. The lead time is also typically around 35 days compared to the average 16- to 18-week lead time associated with new engines.”

Cummins Master Rebuild Centers offer two main options. The first, Ultimate Remanufacture, involves full dismantling and reassembly of an engine, and replacement of all worn components with Cummins parts, including ‘fair wear and tear’ parts. These engines are dyno tested against more than 20 critical parameters. Ultimate engines come with a full factory warranty and have the same life-to-overhaul expectations as a new engine. The second option is called Advanced Rebuild. This is a rebuild as per Cummins standards with a 12-month warranty for new parts and a three-months workmanship warranty. The engine is also dyno tested.

“Every component goes through a detailed inspection to determine whether we need to replace it, or recondition and reuse it,” said Galic. “With Ultimate, the customer gets a fixed price, regardless of the scope of work we undertake, one-year unlimited hours warranty or a two-year or 2,000-hour warranty. The engine is tested against zero build tolerances, so the expected performance is like new. With Advanced, the scope of work is a bit shorter, the warranty is also shorter and there is no policy coverage. The life-to-overhaul expectation is less than for a new engine but, of course, the price is very attractive. There are options to suit every customer’s needs and budget.”

Rather than being a new concept, remanufacturing of engines has been standard in mining for some time. In fact, Galic said that demand from the mining industry has been a catalyst for the establishment of remanufacturing facilities in certain markets.

“In many geographical areas, rebuilt high horsepower engines outsell new ones,” he said. “Mining is really picking up, particularly in Europe, and companies are keen to extend the life of their assets to counteract depreciation. If you consider that some engine cores can be rebuilt to an ‘as new’ standard two or three times, then you can see how rebuilding becomes economically viable.

“Globally, Cummins is building a bank of engine cores and, for some customers, we’re doing the remanufacturing process upfront. When a customer needs to have engines for a replacement, they simply return the old cores to us, and we give them remanufactured ones which can be put straight back into the equipment with minimal downtime. We then remanufacture the old engines and store them ready for their next engine swap. This works really well for mines that have a large population of trucks with the same engine.”

Remanufacturing engines can help mines towards their sustainability goals as well as economic ones. The new Master Rebuild Center in Poland is a ‘green facility’; it will run on renewable energy produced using its own solar panels, uses a closed-loop parts washing system to minimize water consumption, and reuses or recycles as many components as possible.

“Reusing and remanufacturing components cuts down on shipping massively,” explained Galic. “It takes 85% less energy to remanufacture an engine than to produce a new one which is critical for mines that have decarbonization targets to meet. Also, with remanufacturing, it doesn’t matter how old the engine core is, because every engine is updated to the very latest specifications. Often that means the fuel consumption and energy efficiency is much better which results in both sustainability and financial gains for the user.”

The first point of contact for customers who are interested in finding out more about rebuilds is the local Cummins aftermarket team. Galic said these representatives will liaise with those at the Cummins’ Master Rebuild Center to arrange quotes and timings.

Dana Introduces Spicer Electrified e-Transmission

At the bauma 2022 tradeshow, Dana introduced its Spicer Electrified eSP502 e-Transmission; a flexible platform designed to support the electrification of vehicles across the construction, mining, material handling, and forestry markets.

The eSP502 e-Transmission offers a dual-motor, two-speed design that is built on a flexible platform to enable optimized performance at maximum efficiency in a compact package. Dana said the modular approach to the transmission design allows for a single-motor solution, as well as an optional power take-off, depending on the specific vehicle requirements. The eSP502 comes with next-generation control software and functional safety readiness, enabling easy installation and smooth integration, and it features a patented clutch design that minimizes clutch drag to maximize efficiency.

The dual-motor version supports continuous power outputs up to 326 horsepower (240 kW), while the single-motor configuration is engineered for 187 horsepower (140 kW) of continuous output. It is equipped with Dana TM4 high-voltage motors up to 800 volts to improve efficiency, reduce total package size, and provide redundancy as needed.

The eSP502 e-Transmission’s compact and modular design allows it to be adapted for use in 4×2 or 4×4 vehicle applications with a range of ratio options to support a variety of vehicle types, including wheel loaders and rough terrain cranes, terminal tractors and load-haul-dumpers in underground mining.

Liebherr Looks to Hydrogen

At SteinExpo, a tradeshow held in Germany in August 2023, Liebherr provided insight and outlook into its work on selected alternative drive technologies specifically for machines in the mining industry. The wide range of applications its machines cover requires a variety of drives, and Liebherr is working on electric and hydrogen-based drives, as well as options for alternative fuels, like hydrotreated vegetable oils (HVO) and e-fuels.

Hydrogen-based drivetrains hold much promise in mining as they meet the energy-intensive requirements of these applications. Following the presentation of the R 9XX H2, the first crawler excavator with a hydrogen combustion engine at bauma 2022, Liebherr said it’s aiming to commercially launch hydrogen-powered products in the near future. In comparison to electric drives, the advantages of the hydrogen-based drive concept include independence from a permanent energy supply as well as fast refueling times. At the same time, the machines deliver comparable overall performance as their diesel-powered counterparts.

The H966 hydrogen combustion engine was on show at SteinExpo. This was developed by Liebherr Machines Bulle SA in Switzerland for demonstration and field trials and is based on intake manifold injection technology (also called PFI). Liebherr said the results achieved “show the enormous future potential of hydrogen propulsion systems and speak in favor of their use, especially for off-road applications.”

In addition, the company’s Components product segment is working on other hydrogen-based propulsion technologies, such as H2 direct injection. The latter enables a higher power density than the familiar H2 intake manifold injection system and is therefore suitable for heavy-duty applications in demanding environments, such as mining.

By 2025, Liebherr’s Components product segment plans to start series production of hydrogen engines. The company is also researching additional injection solutions to further optimize combustion and power density. Alongside hydrogen-powered engines, the group is conducting several research projects to investigate the use of alternative fuels. One example is a dual-fuel engine that can run on hydrogen with HVO injection, or on pure HVO.

Liebherr is also working on fuel cell technology as another form of hydrogen conversion. An initial, early concept study of a prototype wheel loader powered by a fuel cell was demonstrated in 2022 as part of the Liebherr showcase at bauma.

Caterpillar Introduces New Stator Design on D10

In May 2023, Caterpillar launched its new D10 dozer. Featuring a stator clutch torque converter and load-sensing hydraulics, the new design is up to 6% more efficient than its predecessor, the Cat D10T2.

The new D10 is powered by the Cat C27 engine, which offers aftertreatment solutions to meet US EPA Tier 4 Final/EU Stage V as well as Tier 2 equivalent emissions standards for the global market. The C27 switches power settings based on travel direction to offer up to 20% more power in reverse, reducing cycle times. Caterpillar said that, in addition to delivering productivity gains of up to 3%, the new D10 offers up to a 4% fuel consumption advantage over the D10T2 and up to 10% over the D10T. 

The dozer’s new torque converter design with stator clutch automatically frees up the stator when torque multiplication is not required, improving drivetrain efficiency and reducing the D10’s fuel consumption. This component has proven its worth on the D9 and D11 dozers and, as such, Caterpillar has now opted to add it to the D10 too. 

Most dozers utilize one of two design options: either a free wheel stator which provides high efficiency, but not necessarily the highest rim pull or drawbar, or a fixed stator which usually offers more torque but less efficiency. Caterpillar’s new design provides the best of both worlds, as the clutch allows the stator to be turned on and off. During high-load and retarding conditions, the stator automatically locks to provide the maximum drawbar capability, and, in low-load states or applications, the stator unlocks to maximize fuel efficiency. This technology is seamlessly integrated with the machine’s controls to ensure optimal drivetrain efficiency and less fuel consumption, with no disruption to the operator’s workflow.

In addition to the new stator, the C27 engine in the D10 features multiple improvements, including a 50% larger oil sump compared to the D10T2. This improves the average oil quality, extends the oil change intervals from 250 to 500 hours and reduces maintenance time. Internal fuel lines in the head reduce the risk of leaks and external damage, again, reducing the need for maintenance. The dual coolant pressure sensor offers early coolant leak detection and the ability to detect high- and low-pressure states. Additionally, the radiator cores, which are usually stacked, are now on a single plane for better cooling efficiency. .

Normet Launches the XL ElectroDynamic Platform

In March 2023, Normet announced the pairing of its XL vehicle platform together with its ElectroDynamic (ED) powertrain architecture. By combining the best features of its battery-electric SmartDrive platform and the company’s low-emission engine technology, Normet said the new ED architecture allows for increased payload capacity with compact outer dimensions, high performance, fuel efficiency and less need for maintenance.

The ED technology eliminates the need for a drive shaft and gearbox as the externally cooled mining axles are driven by permanent magnet motors in a highly efficient direct-drive configuration. This not only renders a low and compact load-end design, instant torque and economical electric retardation, but also significantly increases component lifetime.

Samu Kukkonen, Technology Director at Normet, said: “As we were developing our battery electric SmartDrive equipment, we quickly realized that we could remove the drive shaft and gearbox. This is monumental, because now we can use the space where the drive shaft used to be for increased payload capacity. This was achieved by using electric motors at the axles powered by a low-emission engine-generator set. What is more, we have years of experience with all the components used in the architecture not only from our SmartDrive equipment, but also from our engine-powered equipment.”

The ED architecture also enables one-pedal driving, where the vehicle automatically controls both acceleration and deceleration with the operator’s accelerator pedal input. The first application is the Utimec XL 1100 Agitator ED. With a concrete transportation capacity of 10.5 m³, it’s designed for concrete transportation in underground mines and tunnels with a minimum tramming height of 3.3 m.

Rolls-Royce Opens New Assembly Plant in Germany

Rolls-Royce opened a new assembly plant for its mtu Series 2000 engines in Kluftern near Friedrichshafen, Germany in June 2023. The new production facility, which was announced in 2021 and involved a multi-million-euro investment, creates space for assembly and shipping. The assembly of mtu Series 2000 engines will be relocated to Kluftern, enabling the modernization of the existing assembly halls in Rolls-Royce’s Plant 2 in Friedrichshafen, which will provide long-term production space for the Series 4000 engine. The Kluftern plant currently employs 110 people.

The new production building has been designed to be highly energy-efficient and climate-friendly. For example, a 1.2 MW-peak photovoltaic system provides green electricity, e-charging columns ensure clean mobility solutions, and an intelligent building control system alongside other equipment measures will ensure energy-efficient operation.

Series 2000 engines are used worldwide as propulsion systems for yachts, ferries, tugs, wind farm supply vessels, mining vehicles and emergency power generators.

Dr. Jörg Stratmann, CEO of Rolls-Royce Power Systems, said: “Our investments are a clear commitment to the region and to our products and solutions, which are important building blocks of the energy transition in various application areas. We are
convinced that, in conjunction with sustainable fuels and new technologies, the internal combustion engine will play a central role in the future. Because it’s the fuel that matters, not the engine.”

Rolls-Royce is focusing on developing engines that can run on a wide range of sustainable fuels, replacing fossil fuels and reducing carbon dioxide emissions. In addition, the company has already launched hybrid systems for rail, shipping and energy, as well as intelligent automation systems. This will enable the company to provide climate-friendly propulsion technologies in the future for applications where complete electrification is not an optimal solution in the long-term.