The Cat highwall mining system offers an innovative and efficient method for extracting coal from exposed seams in a multitude of applications.

The HWM300 works on the pit floor or bench directly in front of the exposed seam. Up to 300 m (1,000 ft) long parallel rectangular “drives” are cut into the coal seam by means of the cutter head module and push beams (unmanned coal-conveying elements).

These push beams transport the cut coal internally via two counter rotating spiral conveyors (augers) back to the entry of the drive and then onto a stockpile.

The whole mining cycle is completed by a 3-4 man crew with no personnel ever going underground.

Whether you’re operating a trench, open cast or contour mine, the Cat highwall mining system can extract coal affordably and safely:

• Open cast: Highwall mining is used to mine coal from underneath the final highwall, when the strip limit is reached due to economic reasons or surface conditions
• Contour mining: In a mountainous area, the Cat highwall mining system can follow a coal seam along the side of the hill
• Trench mining: The unit mines coal from both sides of a purpose-prepared trench; this mining method is used when an open pit is not an option

You can begin your own feasibility study by visiting our site evaluation tool located on the Highwall Miner product page of http://www.cat.com/en_US/products/new/equipment/highwall-miners.html. From there, Caterpillar and its dealers can assist with highly skilled experts to determine if highwall mining may be right for you.

The power head propels the cutter module and push beam string forward using two hydraulically powered sump cylinders with a 6.86 m (22.5 ft) stroke. The power head also drives the augers which are located inside the push beams. The pushing force of 133 tonnes (147 tons) propels the cutter module to a depth of 300 m (1,000 ft) and the pulling force of 275 tonnes (303 tons) retracts it safely.

Through appropriate Cutter Module selection the HW300 can be tailored to mine coal seams as low as 711 mm (28 in) or as high as 4500 mm (177 in).

Caterpillar offers four electric cutter modules: extra low seam, low seam, mid-seam and high seam. The cutter modules are interchangeable and quickly attached to the highwall mining system. The cutting cycle is fully automated, yet allows the operator to manually adjust the machine function using an ampere reading as the coal seam varies. This proven technology allows the cutter module to accurately follow the coal seam and produce a product near inherent ash levels.

An optional Gamma Detection system can be used to guide the cutter module through the coal seam, leaving predetermined amounts of coal in the roof and floor. This system also allows the mining of coal in soft roof and/or soft floor situations.

Fiber optic, gyro based navigation and steering is also available as an option on the HW300. This provides operators with very precise cutter module location data in real time for enhanced cutter module steering and control of pillar width.

• The Cat highwall mining system is equipped with a comfortable, climate controlled, pressurized cab that offers full line of sight to the highwall, strip pit, support staff and support equipment.
• The full suspension operator seat and the two user-friendly touchscreens create an ergonomic workplace, placing controls and system information at the operator’s fingertips. The operator uses a computer mouse to run the machine and the graphics-based touch screens are language-neutral, employing globally recognizable icons.
• A programmable logic controller executes all inputs by the operator, manages any automatic features and provides comprehensive diagnostic capability.

• The Cat highwall mining system is a strong, self-propelled machine that operates on contour benches as narrow as 18 m (59 ft).
• It trams easily from entry to entry and discharges coal in tight spaces. An optional right-angle conveyor system discharges coal on the right or left side on narrow benches. It can also discharge onto a stacking conveyor system, where coal is moved to the center of the bench for stockpiling large volumes.
• Four heavy-duty, hydraulically-powered tracks articulate independently in two operating modes – mine mode and tram mode – and can rotate the machine 360°, which improves maneuverability in congested areas. Mine mode is used for moving parallel to the highwall, while tram mode is used when moving from pit to pit.

Cat® push beams are 6 m (20 ft) long, rectangular, reinforced steel box structures joined together to form a string, which connects the highwall mining system to the cutter module.

The push beam string is the backbone of the machine; pushing and pulling the cutter module in and out of the coal seam.

The push beam conveys mined coal internally via two counter rotating spiral conveyors (augers). The enclosed beam protects the coal from contamination and supports the hose chain that supplies control and power to the cutter module.

Other Cat push beam advantages include:

• A strong method of attachment that is secured and disengaged quickly
• A push beam connection that allows the string and cutter module to navigate through coal seam rolls and undulations, even under tough pushing and pulling conditions
• A simple design free of electrical and hydraulic connections
• Push beams can be stacked six high, reducing the amount of storage area required in narrow work sites

A steel-armored hose chain stores and protects all electric power cables, hydraulic and coolant lines, and the control cable to the cutter module. The hose chain is automatically unrolled and retracted on a reel during mining.

The Cat highwall mining system’s operation is controlled by a Programmable Logic Controller, which provides reliable performance for greater uptime. A comprehensive diagnostics system, including troubleshooting assistance, streamlines maintenance procedures.

Two drills mounted on the front of the machine are used to drill into the pit floor up to 2.4 m (8 ft). High-strength pins are then inserted through the base frame into the pit floor to help stabilize the machine and to maintain its accurate position, even under tough pushing and pulling conditions.

For quick relocation over long distances, the Cat highwall mining system can be taken apart in modules. Rapid disassembly and reassembly is facilitated by convenient hydraulic and electrical connectors, and all modules are sized for transport using regular public roads.

Depending on local conditions, the system can also be transported between sites and without disassembly by heavy haul trucks.

Parts and service support for the HW300 are never far away with the global Cat Dealer Network. You can count on our dealers’ skill and knowledge for quality maintenance and high machine availability. Caterpillar and dealer personnel are also ready to help evaluate any potential mine site and its coal seam.

Caterpillar can arrange operational and technical training which covers every aspect of the HW300 Highwall Miner. A two-week training program is offered to new customers and to existing customers as a refresher.

A site-evaluation tool is available on cat.com to help classify the geology before considering this mining system.

Whatever your needs, Cat Financial has the financing solution that will help you expedite your purchase and get your equipment on the job, fast. We offer quick and easy financing, with customized payment plans. You chose Cat equipment because you know Caterpillar offers reliable, productive, and powerful machinery. Now, choose Cat Financial to help grow your business.

• Machine mounted lighting covers the entire machine and the surrounding work area.
• Exterior cab mounted cameras.
• Laminated, tinted safety glass that reduces glare and prevents shattering.

• FOPS certified.
• Seat is adjustable on three axis points for comfort and ergonomics.
• Remote wireless operation is possible.
• Strong and extensive work platforms and hand rails.
• Lockable gates restrict access to the hose reel area.
• Walk areas and steps have serrated grating for traction.
• “Pendant” controls operate the second generation push beam transfer mechanism (PTM-2) providing space and limiting engagement with moving equipment. Crew never works below suspended push beams.
• When moving heavy push beams, positive lock lift hooks are used to securely hold the load. Beams are joined with two simple pins. No high-voltage or fluid connections required. An ergonomically- designed extraction tool helps remove the pins and keeps the crew from excessive bending and lifting throughout the shift.
• The HW300 is designed for immediate shut down by means of emergency stop switches (also called e-stops) strategically located around the machine.
• An Uninterruptable Power Supply (UPS) ensures the machine stops safely, that important data is stored and emergency lighting is activated to help the team safely evacuate if needed. Lights can also be timed in non-emergency situations to stay on for a set period after machine shut down- providing a well-lit exit.
• The HW300 has dust suppression at the power head, the coal discharge and along chain conveyor transition points. The cab and key compartments with sensitive equipment are slightly-pressurized to keep dust out – An exhaust fan inside the hydraulic compartment helps with air flow and venting.
• The extra low seam cutter module grease take up cylinders – reduce the effort, time and equipment needed to adjust and tension the chain.
• Blowback guard on machine front provides protection in the unlikely event of a methane explosion underground.
• Overhead structure enhances safety for those working at the front of the machine.
• Automatic fire suppression for electrical controls and hydraulics installed in the housing compartment.