Komatsu unveiled the WX11 in Tucson during February. (Photo: Steve Fiscor)

New models offer high power to weight ratios with improved performance

By Steve Fiscor, Editor-in-Chief

Productivity underground is directly proportional to the performance of the load, haul, and dump (LHD) solution. The entire mining cycle depends on how quickly the LHDs can load the muck from the heading. That in large part depends on the weight and size of the machine and the breakout forces it can apply to crowd the muck pile, load the bucket and haul its load to the dump point.

Several of the original equipment manufacturers (OEMs) that build LHDs have made important announcements recently. What follows is a compilation of those announcements.

Komatsu Introduces WX11 LHD

During late February, Komatsu unveiled its new WX11 LHD at its inaugural Hard Rock Days demo at the University of Arizona’s San Xavier underground mine in Tucson, Arizona. E&MJ had an opportunity to see the company’s latest underground hard rock mining equipment in action, learn about the latest innovations from MST Global and talk to product experts about Komatsu’s newest hard rock machines and solutions.

With an operating weight of 77,750 lb (35,250 kg), the WX11 LHD has an 11-metric ton (mt) payload. Komatsu said the payload combined with the best-in-class breakout force will maximize productivity and provide a lower total cost of ownership for mine operators. The company explained that the WX11 also showcases its commitment to providing underground hard rock miners with a load, haul and dump solution, integrating next-generation data management capabilities, operator ergonomics, intuitive controls and compliance with EU Stage V emission requirements.

“The WX11 is a game changer for hard rock miners. Developed through a close partnership between our experienced team and our longtime customers, this product reflects a shared commitment to design excellence,” said Ryan Karns, Director of LHD and Truck Products at Komatsu. “The WX11 is the LHD every miner will want to have in their operation.”

As a new model within the Komatsu hard rock family of products, the WX11 is designed to be a class-leading LHD for all underground mine operators and contractors. With ease of operability, superior performance and ground-level maintenance position, the WX11 has several competitive edges in the 10-mt LHD class.

The WX11 is powered by a 280-hp (209 kW) Cummins diesel engine, which is available as: Canmet, MSHA, EPA Tier 3/EU Stage IIIA and EPA Tier 4F/EU Stage V. Swing-out radiator fan assemblies support quick washdowns. It has heavy-duty hard rock Komatsu axles with SAHR brakes, and Komatsu cylinders and accumulators. The cabin has an adjustable ride control with onboard telemetry.

2 Cat R2900 XE Beauty shot 1-min

Cat compiled considerable data on its R2900 XE during a side-by-side comparison with the R2900G. (Photo: Cat)

Cat Tests Diesel-electric LHD

Caterpillar introduced the R2900 XE last year, positioning it as the next evolutionary step in pushing the boundaries of loader performance and efficiency. The company said its first diesel electric LHD model meets the needs of today’s mining industry for bigger payloads, faster loading and reduced emissions. It features optimized lift arm and component geometry plus load-sensing hydraulics to elevate lift breakout force to 32,500 kg (71,650 lb) and calculated tilt breakout force to 42,000 kg (92,594 lb), an overall 35% improvement in breakout force from the R2900G. Its field-proven switch reluctance (SR) electric drive system with continuously variable speed control provides 52% quicker acceleration and improved machine response over the R2900G.

A six-month, Caterpillar-conducted study of the new R2900 XE followed the unit for more than 1,500 operating hours to compare its performance to that of the mine site’s existing fleet of five R2900G units. The R2900 XE was equipped with an 18.5-mt (20.4-ton) rated bucket, and the R2900Gs were equipped with 17.2-mt (18.96-ton) rated buckets.

Field follow data showed a 34% average fuel consumption reduction with the R2900 XE, primarily due to its SR electric drive system and hydraulic piston pumps. The new R2900 XE also offered 54.9% lower CO emissions at high idle, while NOx emissions were 34% and 42.1% lower at idle and high idle, respectively. Diesel particulate matter was lowered by 99.99%, comparing the R2900 XE EU Stage V/U.S. EPA Tier 4 Final engine to the Tier 2 of the R2900G.

Lower CO and NOx emissions data demonstrated an improved working environment for personnel at the mine using the R2900 XE. Beyond reduced exhaust emissions, a 7° to 11°C (44.6° to 51.8°F) reduction in working area temperatures were recorded. At the same time, the R2900 XE operates quieter and reduces exposure to vibration levels compared to its predecessor.

The new R2900 XE offers an impressive reduction in tire wear, which Caterpillar attributes to the new traction control system design. Traction control reduces tire spin in difficult underfoot conditions to improve productivity, increase tire life and reduce consumable costs.

The R2900 XE, with its higher bucket capacity, provided a 101.6% increase in ton-per-hour productivity on a duty cycle pulling material from the same loading source to destination. The field follow results also demonstrated a 20% increase in lift capacity over the mine’s current LHD models, and the R2900 XE delivered 3-pass loading — compared to the R2900G’s 4-passes — of the mine’s AD60 and AD63 trucks, equipped with the mine’s preferred body size.

At another Australian underground mine, Caterpillar evaluated the performance of the R2900 XE against the Cat R3000H. The performance and payload study included the same draw points measured in the field follow for each loader, and material was dumped at the same tipping location at the mine’s underground crusher.

The R3000H offers a rated payload of 20 mt (22 tons), today the largest LHD in the Cat line, and was equipped with a 10.5 m3 (13.7 yd3) bucket. The smaller R2900 XE’s rating is 18.5 mt (20.4 tons), and it was fitted with a Cat 9.2 m3 (12 yd3) bucket for the study. Even with the smaller bucket and rated payload, the R2900 XE outperformed the larger loader as anticipated by Caterpillar.

The reasoning behind its higher productivity was in part due to the R2900 XE filling its bucket 15% faster, in just 11 seconds. Additionally, the new LHD clocked a much faster fully loaded acceleration speed with its electric drive system compared to the R3000H, delivering faster cycle times.

On top of offering higher productivity, the R2900 XE burned 13% less fuel than the R3000H over the same application. This equated to a 12% better tons/liter of fuel productivity result.

The mine site plans to equip its future R2900 XEs with a 9.8 m3 (12.8 yd3) bucket. Using the larger bucket, the mine could realize a potential extra 6% increase in productivity gains compared to using the 9.2 m3 (12 yd3) bucket.

A third Australian study pitted the R2900 XE against a competitive LHD model with a published rated payload just over 17 tonnes (18.7 tons). The study’s objective was to clear the same amount of material from the same specified area.

The R2900 XE cleared the area in 20 buckets compared to the competitive LHD’s 24 buckets, was 17% faster in clearing the development and loaded the haul trucks faster. Plus, the measured operating heat generated by the R2900 XE was 7.1°C (44.8°F) lower on level ground and 11°C (51.8°F) lower on the decline than the competitive LHD.

In comparative working conditions, the R2900 XE had an 8% lower fuel burn rate than the competitive LHD, saving on fuel costs. The R2900 XE also delivered a 20% faster average cycle time on level ground and a 23% average cycle time advantage when traveling down the decline compared with the competitive model.

3 Paus PFL 8-min

The PFL 8 performed well in a narrow vein gold mining operation. (Photo: Paus)

The PFL 8 Explores for Gold

Paus said its PFL 8 loader offers the highest breakout force for narrow vein exploration and mining. The 1.5-mt LHD is made for the toughest conditions and convinces with performance and reliability. 

Since November 2022, Golden Compass Jambly has been using the PFL 8 at a gold mining exploration project, which is 3,300 m above sea level. After the operation started with an inefficient chain conveying system, the operator switched to the modern, more productive method to use an LHD for narrow vein operations. The Paus PFL 8 matches its needs to use a modern, robust machinery with high safety standards.

After 138 m into a new section of the mine it was exploring gold for the first time. The challenge for the mine was to find a machine, which could be used in a small section with just 9 m2. Paus said the PFL 8 was the only machine available on the market, which could meet the requirements of the mining customer. After 7 months of operation the machine has logged 1,000 hours and has moved tons of ore. Golden Compass likes the easy and fast handling of the hydrostatically driven loader which makes it very efficient.

One of the biggest advantages of the PFL 8 is its compactness and great overview in both directions which makes material haulage fast, safe and more productive. The optimized dimensions allow small turns for narrow vein mining. The machine can be operated in 2.2-m-wide galleries of 2.2. With a bucket volume of 0.8 m3, it has the high power to weight ratio that mining and exploration companies like.

Safety starts with a safe access into the operator’s canopy. Paus has the unique design that the operator enters safely its working environment from the side. This side seated position with a great overview to both directions guarantees safe haulages. The ergonomic and large operator’s canopy is ROPS and FOPS certified and can be equipped with a very large number of safety features like collision warning systems, 3P seat belt, belt and seat monitoring and much more. Additionally, the machine can be equipped with radio remote controls to work in hazard areas. A door interlock switch automatically applies SAHR brakes, inactive working and steering hydraulics when the door is opened. 

Solutions made for miners include a maintenance concept with easy access to daily checks from the ground. Fast failure analytics for high reliability of the production machine can be done within the canopy integrated diagnostic display. Online web catalog with electric and hydraulic plans makes maintenance easy, fast and lowers costs. 

Multiple jobs with one machine, thanks to a quick-change system the PFL 8 can be equipped with other attachments like dozer blade for road maintenance or with forks for material handling. The Paus solution enables the customer to fulfill different jobs and gives savings in investment costs during the exploration.