The first diesel electric underground load-haul-dump (LHD) loader from Caterpillar, the new Cat® R2900 XE LHD, has officially been launched with a goal of meeting the underground mining industry’s needs for bigger payloads, faster loading and reduced emissions.

Built on the platform of Caterpillar’s most popular underground loader, this new LHD – which was previewed at MINExpo 2021 in Las Vegas – features optimised lift arm and component geometry plus load-sensing hydraulics to improve breakout force by 35% over the Cat R2900G, the company claims.

The world’s first R2900 XE has already been delivered to Western Australia-based gold miner Westgold Resources.

The R2900 XE works faster in tough conditions, delivering 52% quicker acceleration and improved machine response over the R2900G. It accelerates from 0-24 km/h in 6.4 seconds and achieves a 7% higher speed on grade, according to Caterpillar. Variable piston pumps deliver higher flow rates for faster hydraulic cylinder cycle times and powerful lift forces. Boasting a higher, 18.5-t payload for faster load times, the new LHD model offers a 3- to 4-pass match to the Cat AD63 truck for greater efficiency. Combined, these features deliver a 20% increase in productivity for the R2900 XE, Caterpillar says.

The loader’s redesigned buckets are available in four sizes with capacities ranging from 7.4 to 9.8 cu.m to match material density needs for a variety of loading, hauling and dumping conditions. Offering an optimised balance between productivity and bucket life, the full range of Cat ground engaging tools (GET) includes Modular Weld-on, Bolt-on Half Arrow and Durilock™ mechanically attached shrouds. To further protect the bucket, a range of heel shrouds, wear plates and bars are available in weld-on or mechanically attached designs.

The Cat C15 engine on board offers a variety of emission reduction and aftertreatment options, including an EU Stage V/US EPA Tier 4 Final configuration and diesel particulate filter. It delivers the power needed – up to 335 kW – with greater than 31% increased fuel efficiency compared with the R2900G. Its lower engine revolutions per minute results in reduced fuel burn, heat, noise, vibration and exhaust emissions, while offering an increase in power and productivity, according to Caterpillar.

High-efficiency electric drive

Drawing from decades of experience, the new R2900 XE LHD features a switch reluctance electric drive system. It is Caterpillar designed, integrated, validated and supported, and its continuously variable speed control delivers improved power and cycle times, Caterpillar says. With no driveline or powertrain shock loads, it offers smoother directional changing and implemented virtual gears for machine controllability. Automatic retarding controls maintain speed on grade. The drive system prevents coasting in neutral and combines with the anti-rollback feature to further increase operating safety.

Its new axle design offers increased component size and, together with the four-gear planetary final drive groups, provides greater strength and longer life. Larger wheel bearings and increased brake sizing further increase final drive life. Flange-mounted rims allow for safer tyre and rim changes. The differentials and final drives are built to withstand the forces of high torque and impact loads, providing high torque multiplication to reduce drivetrain stress. The traction control system, meanwhile, reduces tyre spin in difficult underfoot conditions to improve productivity, increase tyre life and reduce consumable costs.

The operator environment is built on Caterpillar’s R1700 platform, incorporating the latest improvements in productivity, safety and comfort. The cab’s enclosed design provides fresh, pressurised, temperature-controlled air circulation with air conditioning to enhance operator comfort and decrease fatigue. Resiliently mounted to the frame, the ROPS/FOPS structures isolate the operator from vibration for a more comfortable ride. The cab design incorporates two emergency exits, while available rearview and forward- and rear-facing side-view cameras help to improve visibility around the machine to enhance safety for operators and other workers.

Combining selection of direction, virtual gears and steering into a single lever, the standard STIC™ steering and transmission integrated control delivers maximum responsiveness and machine control, Caterpillar says. Low-effort, electric-over-hydraulic joystick controls feature simultaneous lift and tilt functions to optimise operating efficiency, while a two-pedal design with improved spacing and position facilitates more efficient foot control.

Caterpillar adds that the optional ride control improves cycle times and load retention when operating in rough terrain. By engaging/disengaging the ride control system at preset speeds, the system automatically dampens bucket forces and stabilises the machine, reducing fore and aft pitching motion. It incorporates a nitrogen/oil accumulator system in the lift circuit to act as a shock absorber.

Scalable technology solutions

The new R2900 XE ships from the factory equipped ready for Cat MineStar™ solutions, a comprehensive suite of technology offerings. From machine health monitoring to fully automated haul and dump cycles, scalable levels of technologies can be tailored to meet each mine site’s unique needs, Caterpillar says. Standard Product Link™ Elite boosts machine connectivity by enabling the loader to collect and transmit health and condition monitoring information into locally or cloud-hosted applications.

Mine sites can choose between a range of available MineStar technologies, including:

• Command for underground – enables remote operation of LHD machines, from line-of-sight to full autonomy, allowing operators to be relocated to a safe, comfortable location to improve productivity, efficiency and safety;
• Detect for underground – uses peer-to-peer proximity detection to reduce the risk of unintended interactions between people and machines by “seeing” in the dark;
• Fleet for underground – gives real-time access to accurate information such as cycle time, payload, machine position, and other key operational parameters and automatically tracks and records data up and down the value chain; and
• Health – collects and transmits equipment data necessary for proactive maintenance services and predictive equipment analysis.

New Autodig technology optimises loading by automating crucial parts of the digging cycle, Caterpillar says.

“When combined with Command for underground, Autodig offers a true automated machine, providing high-speed auto tramming and full cycle autonomy,” the company explains. “Featuring an onboard payload weight scale, Cat Payload Management provides material management, cycle count and timing recording, and wireless production detail reporting capabilities. Optional tyre pressure monitoring is fully integrated into the R2900 XE, allowing operators to determine on-the-fly if the tyres are properly inflated.”

With more robust structures, increased powertrain durability, longer lasting components, improved maintenance and extended service intervals, the new R2900 XE can be maintained in less time, helping to lower cost-per-tonne operation, Caterpillar says. The machine’s electric drive reduces the number of moving parts compared with traditional mechanical drive systems. Extended oil change intervals, together with the electric drivetrain, reduces the amount of oils used. Sight gauges visible from ground level simplify fluid level checks, and all filters are positioned vertically to provide spill-free servicing, Caterpillar claims. Electrical connectors are sealed to lock out dust and moisture, while harnesses are covered for protection.

Machine design eliminates castings and reduces weight to increase the life and strength of the frame without sacrificing performance. The frame, powertrain, engine and components are built to be rebuilt using new, remanufactured, or rebuilt parts and components, allowing mines to take advantage of multiple lives of like-new performance to lower operating costs.