Evaluations of noise controls for roof bolting machines used to drill 25-mm-diameter holes.
Yantek-DS; Alcorn-LA; Azman-AS
NOISE-CON 2011. The 25th Conference of the Institute of Noise Control Engineering, July 25 - 27 2011, Portland, Oregon. Washington, DC: The Institute of Noise Control Engineering of the USA, 2011 Jul; :1-15
Roof bolting machine (RBM) noise is a significant health hazard in underground mining because the sound levels at the operator's station often exceed 100 dB(A). Drilling the hole prior to installing a roof bolt is the most significant source of RBM operator noise exposure. The dominant source of drilling noise is the drill steel. A drill bit isolator (BISO) for 25- mm-diameter drilling has been developed to reduce the noise radiated by the drill steel during the drilling process. In addition, a rubber-barrier cover for the chuck has been evaluated. This publication discusses in-laboratory sound level measurements with the 25- mm-diameter BISO and the rubber chuck cover, and in-mine evaluations of the BISO. In the laboratory, the BISO reduced the A-weighted sound level measured near the operator's station while drilling by 5.6 dB, while the rubber-barrier chuck cover reduced the A-weighted sound level at the same location by less than 1 dB. Severe, highly variable roof conditions in the mine made it impossible to determine the effect of the BISO on the RBM operators' noise exposures. However, the in-mine testing provided information that will be used to improve the durability of the BISO.
Noise; Noise-levels; Noise-measurement; Sound; Hearing; Ears; Mining-equipment; Mining-industry; Noise-induced-hearing-loss; Machine-tools; Machine-operators; Underground-miners; Underground-mining; Coal-miners; Coal-mining; Permissible-limits; Exposure-assessment; Exposure-levels; Exposure-limits; Equipment-operators; Tools; Equipment-design; Measurement-equipment; Laboratory-testing; Sound-analyzers; Testing-equipment; Hearing-conservation
David S. Yantek, National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research, 626 Cochrans Mill Road, Pittsburgh, PA 15236
NOISE-CON 2011. The 25th Conference of the Institute of Noise Control Engineering, July 25 - 27 2011, Portland, Oregon