_GENERAL DOCUMENTS - C1981017 (239)

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The Division assumes that a D9U Caterpillar dozer will be used to backfill and rough grade the portal areas: The average push distance is 150 feet, thus the unadjusted production rate for a D9U dozer is 1,000 LCY per hour. The following are the factors which will affect the production (pgs. 42, 43, 500, C11) : Condition Factor Average Operator 0.75 Rock Material 0.70 50 Minutes working time per Hour 0.84 Grade Factor (38%) 0.26 Altitude Deration 0.94 Overall Factor 0.11 with a production factor of 0.11, a D9U can move 110 LCY/hr. Therefore, 244 hours would be required to backfill the Mine No. 1 bench. The monthly iental rate for a D9U dozer (pg. 9-92, BB) is $14,200.00, with an hourly operating cost of $38.25. Adjusting for the 10% location factor, the monthly rental cost is $15,620.00. Assuming 22 days per month and 8 hours per day, the hourly rental rate would be $88.75. Adding the estimated operating cost of $38.25, the hourly rate would be $127.00. Based on this rental rate, backfilling and rough grading the Mine No. 1 mine bench would have• the following cost breakdown: 1 - D9U dozer: ' 244 hours @ $127.001hr. _ $30,988.00 1 - Operator: 244 hours @ $ 15.00/hr. _ $ 3,660.00 TOTAL COST. $34,648.00 The Mine No. 1 storage bench is 2.65 acres and must be backfilled to an average depth of 14.75 feet (see cross-section) . Therefore, 63,061 yd3 of material would have ,to be moved_ All production factors except slope would be the same as previously noted. With a grade factor of 14%, the overall production factor would be 0.33. The average push distance is 150 feet, thus the overall production rate for a D9U would be 330 LCY/hr. Based on this production rate, it would take 291 hours to complete this backfilling operation at the following cost: 1 - D9U dozer: 191 hours @ $127.00/hr. _ $24,257.00 1 - Operator: 191 hours @ $ 15.00/hr. _ $ 2,865.00 TOTAL COST: $27,122.00 19-2 _-- -