Noise controls identified by MSHA which offer potential for noise reduction by having demonstrated effectiveness but lack evaluation or documentation for longwalls include:
Barriers where appropriate
Appropriately selected, correctly installed, and properly maintained acoustical materials
Rotation of head and tail shear operators with each other, shear operators with shieldman, stageloader operator with shieldman
Video cameras to monitor the cutting and other functions to limit miner exposure
Enclosure of motors, gears, pumps where demonstrated to be a significant noise source and can be done without damage to the equipment
Damping of enclosures and panels where demonstrated to be a significant noise source
Water-cooled motors instead of air-cooled motors where practical and when the motors are a significant source of noise exposure
Isolated cutting bits on the longwall drum, for example the application of vibration isolation materials between the bits/block and the drum
Sand-filled cutting heads
MSHA also considers the following engineering noise controls to be technologically achievable in reducing the noise exposure of miners working around the longwall:
Automated shear
Automated jacks
Automated stageloader
Memory cut
Proper maintenance such as use of proper chain tensioning and flight spacing
Positioning of the miner to minimize the exposure to noise such as keeping stageloader operator away from crusher, motors and gears, head drive, belt tail, head drum shear operator staying a minimum of three meters (10 feet) outby the drum head
Reduced run-time for face and stageloader conveyors when empty
In a case-be-case rationale remote operation may be feasible