Abstract
A demonstration project has been completed to reduce the operator sound level of an underground service vehicle, a personnel dispatch wagon, to 90 db(a) or less. The program objective was to implement quieting recommendations made on an earlier study for the federal Bureau of Mines on diesel-powered mine equipment. The manufacturer and mine to which the vehicle was going actively participated in the program to ensure a product that was not only quiet, but useful. The key element of the quieting package is an engine partial enclosure, which, with several complementary noise control components, reduced the operator sound level 14 db, from 101 db(a). The vehicle underwent a 4-month trial period, with no degradation in the quieting package. Mine personnel reported no maintenance difficulties, and were enthusiastic about the dispatch.
