How Caterpillar is refining its excavator designs to reduce fuel use and maintenance costs, and is also looking at clean energy options.
Caterpillar is to excavators what Van Gogh was to sunflowers. Its long history with these staples of the mining and construction industries goes back to the late 1960s, when mining companies began to need much larger machines. In 1970, Caterpillar responded by introducing a prototype excavator.
Its first customer-ready hydraulic excavator, the 28-ton 225, was ground-breaking in every sense of the word, providing improved lifting, digging and loading capabilities.
Fast forward to today, and Caterpillar’s colossal excavator, the Cat 6090, makes the 255 look like a diecast model. The 6090 has an operating weight of over 1,000 tons and a 4,500 horsepower engine.
Its hydraulic shovel has a mind-boggling bucket capacity of 71.9 cubic yards and a bucket payload of 103 tons. Although no longer in production, it remains the world’s largest hydraulic excavator,
But size is not all that has changed regarding Caterpillar’s excavators down the years, for the company has also refined its designs to reduce fuel use and maintenance costs.
A landmark product in this regard was its 320D, which optimised engine performance, lowering exhaust emissions to meet global regulations.
Next-gen excavators sustainability boon
This paved the way for future models, such as the Next Generation 320 hydraulic model in 2017, which was designed for medium to heavy-duty applications, to help customers meet both environmental and business goals.
By 2022, Caterpillar had implemented this system across its entire excavation product line, and its latest designs use a lower engine speed and larger hydraulic pump to deliver high performance with less fuel consumption.
Caterpillar estimates that implementing the Next Generation system across its excavator range has reduced carbon dioxide emissions by up to 2.2 million metric tons per year.
Chris Lau is Engineering Fellow of Hydraulic Mining Shovels at Caterpillar. His background is in engineering tech-field support, and he has deep expertise in hydraulic mining equipment design.
Lau worked on the now-discontinued 6090’s sister excavator, the 6040. Sustainability and safety features are hallmarks of the 6040. Lau says its power module houses twin C32 engines, meet global emission regulations.
“We offer two configurations, to meet US and EU emission requirements with a maintenance-free after-treatment system.” – Chris Lau, Engineering Fellow of Hydraulic Mining Shovels at Caterpillar.
He adds that its twin-engine design ensures the machine can continue to operate with full functionality if one engine fails, a feature that allows the shovel to move away from high walls and blast zones in emergency situations.
An intelligent pump management system, meanwhile “optimises productivity while reducing energy consumption and component wear”, Lau says.
Battery model excavators
Caterpillar is now looking to take the sustainability of its excavators to the next level, by developing battery-electric models. The company says it is committed to providing solutions that “meet our customers’ sustainability goals today and support them into the future as we power the next generation of machines”.
Caterpillar showcased the future of its excavator range when it unveiled its new line-up of battery-electric powered machines at CES in Las Vegas in January 2024, demonstrating its portfolio of integrated solutions in support of the energy transition.
Visitors were shown two electric machines from opposite ends of the size spectrum. One was the 301.9 mini-excavator and the other was the colossal R1700 XE LHD underground loader for mining.
In all, Caterpillar is working on four battery electric machine prototypes. As well as the above machines, there is the 320 Electric Medium Excavator and the 950 GC Medium Wheel Loader.
At the time of the show, Rod Shurman, Senior VP of Caterpillar’s Senior VP, Building Construction Products Division, said CES was “renowned as the proving ground for breakthrough technologies”, which made it “the perfect venue for demonstrating our leadership in power systems and integrated service solutions to help our customers in the energy transition”.
The 301.9 mini excavator has up to 50% more energy capacity than its peers, according to Alex Kapper, Director of Strategy and Business Development, Caterpillar Electrification & Energy Solutions, in a blog post.
The mini-excavator is also the first machine with a Caterpillar battery, and includes an onboard AC charger. The company’s lithium-ion battery range features a modular design for flexible configurations across multiple applications.
The mini-excavator has a run time of up to eight hours on a single charge. The batteries are engineered to be scalable to industry and customer performance needs, and also to maximise sustainability throughout their lifecycle, including recycling and reuse at the end of life.
But according to Kapper, putting a battery in a machine is just one piece of the electrification puzzle.
E-excavators ‘must be reliable workhorses’
Cat’s mining and construction customers need these machines to work as productively as the diesel-combustion-powered equipment they’ve been using for decades.
“Battery-electric machines will require more on-site support and resources to solve challenges surrounding where to charge them, how to ensure there is adequate power capacity, how to manage energy costs, and where to source lower-carbon energy,” says Kapper.
He adds: “On most construction and mining sites, the infrastructure to handle these tasks either doesn’t exist or hasn’t been developed fully yet, so no wonder some customers are hesitant about adopting electric machines.”
Solutions include on-site power generation capable of running on renewable fuels, solar panels and hydrogen-powered fuel cells. It will also require energy storage solutions that work with any combination of diesel, natural gas or renewable energy sources for optimal power, and chargers tested and validated to work with equipment on harsh construction and mining sites.
“No single solution will work for every mining and construction site,” Kapper says. “But we’re confident there’s a combination that will, and customers can rely on our expertise to select the tools and technologies that make the most sense for their operations. We’re committed to helping them navigate their unique journey to a lower-carbon future.”
