Abstract
This report presents the results of an extensive research and development program to reduce the noise generated during coal cutting. The characteristics and magnitude of continuous miner coal cutting noise sources are defined. This work consisted of development of a simulated coal seam to facilitate aboveground coal cutting tests, noise measurements in a reverberant acoustic chamber during simulated mining operations of a continuous miner (cutting the simulated coal seam), and noise measurements in an underground coal mine during continuous miner operation. In-mine and laboratory test results were in excellent agreement for both a-weighted overall levels as well as a-weighted one-third octave band spectra. Methods to reduce coal cutting noise are presented. These methods take full advantage of the dynamic characteristics of the forces generated during coal cutting. Dynamic cutting force isolation was shown to be a very effective technique. Finally, a continuous miner was equipped with a cutter head that incorporated (among other design factors) cutting force isolation. Successful long-term, in-mine use of the cutter head demonstrated coal cutting noise at the operator's station of less than 90 dba and 50% coal, 50% rock cutting of less than 93 dba.
