Joy 12HM31 continuous miner

Joy 12HM31

  • Solid-head cutting head system
  • 20 tonnes per minute cutting rate for lower to mid-seam applications
  • Individual motors with direct-drive transmissions to power the cutter, traction, gathering, and hydraulic systems
  • Outboard access for motors, gearcases, controllers and other major components to reduce downtime and maintenance costs
  • Remote radio control operations, with different frequencies available for multi-machine sections
  • Optidrive AC electronic system to provide smooth transmission responsiveness
  • Wethead cutting cases to reduce frictional ignitions and respirable dust levels (optional)
  • Faceboss control platform to facilitate an optimal balance of production rate and cost

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The 12HM31 continuous miner, with a cutting rate of up to 20 tonnes per minute, is ideal for lower to mid-seam mining applications.

Cutting system options

The 12HM31 is a solid-head cutting head system, with a variety of cutter bit spacing configurations available.

Multiple models available

The 12HM31 comes in multiple models, making it easy to select a model that fits your mining application:

  • 12HM31-AAA standard version
  • 12HM31-B with 950V Optidrive and mini-megahead
  • 12HM31-B with 950V Optidrive and megahead
  • 12HM31-MKII high voltage version with megahead

Conveyor system

The conveying system on all 12HM series machines features a 965 mm (38 in.) conveyor to provide increased production capability. 12HM series machines come with a standard single rear conveyor drive; however, an optional dual rear conveyor chain drive is also available.

Haulage system compatibility

The 12HM series continuous miners can be customized, using different conveyor lengths and conveyor chain speeds, to optimize your batch or continuous haulage systems.  In addition, we can also supply a conveyor to match your attached haulage system.

Traction system

The 12HM31 traction system includes our patented Optidrive AC electronic system, which is coupled to a compact, all-gear transmission to provide smooth, reliable service. The variable speed control allows the operator the ability to smoothly and accurately move the machine short distances during tramming maneuvers in a typical room and pillar layout.

The cutter motor feedback and the traction differential features optimize sump performance even in the most demanding applications. Finally, the brushless AC traction motors are highly reliable and require minimal maintenance.

Optimized fluid controls

Our hydraulic manifolds, standard on all continuous miner models, reduce hose assemblies and fitting counts to significantly reduce hydraulic fluid leak points; improved sealing in all areas means less oil leakage as well.  All serviceable parts for a circuit are in one common location and all pressure check points allow gauge connection/disconnection while the pump is running. Screw-adjusted relief valves are standard, while bolt-on caps permit easy access for troubleshooting/replacement on hydraulic or water segments.

Bolt-on traction reducer

The bolt-on traction reducer, exclusive to the South African market, provides a full bolt-on solution, including the planetary as part of the assembly. 

Machine weight  All models  113,000 kg
Maximum cutting height  AAA
 B (mini-megahead) 
 B (megahead), MKII
 3,800 mm
 4,650 mm
 4,800 mm
Minimum cutting height  AAA
 B (both) & MKII
 1,600 mm
 2,300 mm
Minimum tram height  AAA, B (both)
 1.6 m
 2.2 m
Conveyor width  All models  965 mm
Cutterhead power
@ 950V 60 Hz for AAA and B 
@ 3300V 60 Hz for MKII 
 AAA & B (mini-megahead)
 B (megahead)
 140 kW
 175 kW
 260 kW
Total machine power
@ 950V 60 Hz for AAA and B 
@ 3300V 60Hz for MKII 
 B (mini-megahead)
 B (megahead)
 612 kW
 612/643 kW
 682/713 kW
 889/920 kW

Faceboss control system

Competitive and market pressures mean that you have to produce product at an ever-increasing rate, while always striving to decrease your cost per ton. These goals are only made more difficult by the worsening attributes of available reserves and deteriorating operating conditions.

The Faceboss control system enables your operators to operate equipment at an optimal balance of production rate and cost per ton using a powerful tool set that includes operator assistance tools, automated sequences, advanced diagnostics, machine performance monitoring, and analysis tools. Faceboss is the standard control system platform on all Joy underground mining equipment, which ensures that you receive the same level of optimization for all your Joy equipment.

Learn how Faceboss can help reduce your operating costs. 

Optidrive AC

Joy Optidrive, an AC variable-frequency drive system, integrates software with the electronic and mechanical systems to provide the following features:

  • Increased tram speed: Significantly increases the tractive effort available, improving the equipment’s ability to climb gradients and negotiate difficult roadway conditions
  • Regenerative braking: Supplements the mechanical brakes, allowing them to run cooler with extended wear life; regenerative braking is highly effective at automatically maintaining constant speeds when descending gradients
  • Less maintenance: No commutator brushes to inspect and replace mean AC traction motors are typically more reliable, more durable, and require less maintenance than DC traction motors

Learn how Optidrive can help improve your productivity. ​

Scrubber systems

The Joy scrubber system - an auxiliary dust control system integrated into the continuous miner - works with the mine ventilation system to help reduce overall local dust exposure. The major system components include:

  • Ductwork
  • Impingement screen
  • De-mister
  • Fan
  • Attenuator

Our scrubber systems can be configured to support localized face ventilation plans by selecting the air volume along with the inlet and discharge locations.

Wethead cutter cases

Optional Joy Wethead cutter cases can be integrated in the cutter head to produce a fine spray behind each cutting bit on the cutter drums, thereby:

  • Cooling sparks at point of creation to reduce the potential for frictional ignitions
  • Reducing respirable dust levels to improve operator safety
  • Reducing suspended dust to increase visibility
  • Lubricating the cutter bits to improve cutter bit lifespan

The Wethead system consumes less water (114 lpm (30 gpm) water flow required)) than standard miner dust sprays and features a dedicated in-line filtration. Finally, the back-to-back carbon-face water seal is designed to run dry for extended periods of time. 

Learn how Wethead keeps your mine environment safer. 

SmartZone proximity system

The SmartZone proximity system is an integrated training device that helps teach your personnel to operate a continuous miner from safe working zones, as well as stay clear of related danger zones. The SmartZone system tracks, recognizes, and logs operator movements around the machine to provide in-depth analysis for your training initiatives.

Learn how SmartZone keeps train your mine personnel.


The SmartConveyor uses the latest sound abatement technologies to reduce sound output while improving maintainability. Research results have shown a 45% and 65% noise exposure reduction for the operator when compared to a standard machine (Mining Engineering, 2011, Vol. 63, No. 7, pp. 83). SmartConveyor combines our patented dual-sprocket conveyor chain and auto-tensioning features to improve the operating environment.

The patented Joy dual-sprocket continuous miner conveyor chain:

  • Provides 50% improvement in tension strength (over conventional chains)
  • Driven by two parallel eight-tooth sprockets to provide better torsional rigidity

The increased contact area between the chain and sprocket, coupled with the use of abrasion-resistant materials, significantly decreases the amount of wear, increasing the working life of the components and reducing the probability of abrupt chain breakage. In addition, the cam-style adjusting mechanism automatically compensates for chain slack as the conveyor swings.