An experimental investigation of the sound level produced by bulldozers with various maintenance schedules
This study was made to understand and evaluate the effect of maintenance on noise production from bulldozers through experimental measurements of sound levels in a large open cast mine. Assessment of sound pressure levels at each periodic maintenance interval revealed that maximum sound level reduction was achieved at 1000 h maintenance schedule. For other periodic maintenance intervals, reduction in A-weighted sound pressure level was below 1.0 dB. The study revealed that primarily, the major noise-generating systems in Heavy Earth Moving Machinery (HEMM) are air, exhaust, cooling and fuel systems. However, maintenance of lubricant, transmission and hydraulic systems yielded no significant improvements in sound levels. Results also indicated sound level emissions from various systems to lie in different frequency ranges.
Keywords: experimental investigation, bulldozer sound sources, frequency analysis, noise spectrum, preventive maintenance schedules, removal technique, vehicle noise, bulldozers, open cast mining, sound pressure levels, heavy earth moving machinery, heavy vehicles