MSHA have identified the following engineering and administrative controls effective in reducing noise exposure to miners operating on or working around continuous miners, augers and underground loaders.

Remote control with proper positioning of the operator

Treated cutting heads on auger miners, such as the application of stiffening gussets to the helix and filling voids with sand

Proper maintenance, including replacing bent or misaligned conveyor flights or sides and use of a chain with proper tension or one having an automatic chain tension device

Locate the shuttle car change-out point away from major noise sources, such as an auxiliary fan

Avoid idle parking in high noise areas

Keep miners away from auxiliary fans

Have mechanics and electricians avoid working near high noise sources during maintenance

Reduce utility personnel working time near the face and auxiliary fan

Limit operation of empty chain conveyors on all equipment, including the shuttle car, loading machine, continuous miner, mine-bolter and feeder breaker

Eliminate a high-pitched screech by instructing roof bolters to drill straight holes and to avoid metal strap contact with the drill steel

Follow a cutting cycle to minimize noise generation from both the continuous mining machine and the cutting process. For example, reduce cutting into roof and floor rock, cutting directly into in-seam rock and over sumping

Regulate engine RPM on diesel-powered shuttle cars during loading and dumping

Follow shuttle car loading and tramming procedures that minimize noise. For example, in times the conveyor chain is turning, increase distance from continuous miner and its boom

Follow loading and tramming procedures for loading machines that minimize noise

Turn off any mobile equipment when not in operation

Maintain proper fan blade clearance on dust scrubbers associated with continuous miner machines

Constrained layer damping on the conveyor pan on an auger miner. For example, the application of visco-elastic materials covered with wear steel to isolate the chain and flights from the conveyor pan line

MSHA also identified the following engineering controls as offering promise in reducing exposure:

Transparent barrier between operator and conveyor pan line

Constrained layer damping on the conveyor pan on a continuous ripper miner. For example, in the application of visco-elastic materials covered with wear steel to isolate the chain and flights from the conveyor pan line

Sand-filled conveyor decks

Enclosure and isolation of motors and pump housings where they have been demonstrated to be a significant noise source

Vibration isolation mounts on motors/pumps where they have been demonstrated to be a significant noise source

Chain conveyor with coated flights

Isolated cutting bits, such as the application of vibration isolation materials between the bits/block and the drum

Sand-filled cutting heads

The following administrative control offers promise:

Rotate center bolter operator with center bolter helper, roof bolter operators with utility personnel or shuttle car operators, miner-bolter operator with loading machine operator, or continuous miner operator with shuttle car operator

According to MSHA, the following noise controls offer promise for dust scrubbers associated with continuous miners:

Silenced fan housing

Sleeve-style attenuators

Alternative face air flow distribution systems, such as spray fan systems

Bolt-on attenuators

Appropriately selected, correctly installed, and properly maintained acoustical materials applied to the dust scrubber