Laserfiche WebLink
Lwi <br />r• <br />lj <br />• <br /> <br /> <br />L <br /> <br />r~ <br />L• <br />observed. At 8 KHZ sound levels had increased by more than 15 d6 <br />to 65 d6. This increase at such a high range may be indicative of <br />wear induced noise and will be noted carefully during the next <br />study period. At site F-3 data showed a 2 dBA increase with a 5 <br />d6 decrease at the 250 Hz frequency. <br />b) Transfer Tower - Sites TT-1, 2 <br />Transfer tower site octave band curves were similar to previ- <br />ous measurements. However, at Site TT-1 low frequency sound <br />levels increased by 6 d6 from September, 1979 values. A-weighted <br />sound levels remained approximately the same. <br />It is important to note that measurements taken near the <br />transfer towers are highly dependent upon the amount and quality <br />of coal being transported any particular time. <br />c) Crusher Area - Sites C-1, 4, 6, 8, 10 <br />Results at individual sites are addressed below. All <br />measurements were recorded in the absence of haul trucks. Normal <br />- operating conditions included continuous coal transport on belts 1 <br />to 4. Belt 5 was not operating. The stockpile maintenance front <br />end loader was inactive. Site measurement results were: <br />Site C-1 <br />The A-weighted sound level was 67, down 3 dBA from last <br />September and roughly the same as previous measurements. The <br />octave band profile remained essentially unchanged. <br />r~ <br />L <br />