1999-09-01_REVISION - M1988112 - Laserfiche WebLink

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• Haul distances vary from 500 feet to 2,000 feet • An average one-way haul distance of 1,400 feet is assumed • Total resistance (grade and rolling) is 8% Cycle time: Loaded 3.75 minutes Empty 2.5 minutes Total cycle time = 6.25 minutes (grade adjusted) • Haulage volume 20 yd3/load • Unadjusted production rate 60 minutes hour / 6.25 minutes/load (20 yd3/load) = 192 yd3/load • Production rate adjustments for 0.83 job efficiency and 0.92 operating altitude 192 yd3/hour (0.83) (0.92) = 146 yd3/hour • Scraper time required per acre = (2,420 yd3/acre / 146 yd3/hour) = 16.5 hours • Total estimated cost = 16.5 hours ($140/hour)=$2,310/acre ~~~[ ff/~~ A.3 Topsoil Grading Topsoil grading using a D-8N tracked dozer with a U type blade will require: • Average push distance 50 feet • Production rate 1,400 yd3/hour • Job efficiency is 0.83 • Slope adjustment for 10% is 1.2 • No attitude adjustment is necessary • Operator efficiency (average) is 75% • Material type adjustment (loose-stockpile) is 1.2 • Weight correction factor -soil 1.0 (i.e., soil weight estimated to be 2,300 Ibs/yd3 the D-8N has a rated capacity of 2,30016s/yd3) Weight correction factor = 2,3001bs/yd3 / 2,300 lbs/yd3 = 1.0 • Adjusted production rate 1400 yd3/hr (0.83)(1.2)(.75)(1.2)(1)=1,255 yd3/hour • Dozer time required per acre = (2,420 yd3 / 1,255 yd3/hour) = 1.9 hours • Total estimated cost = 1.9 hours ($135/hour) _ $257/acre 13~1~ A.4 Waste Rock Contouring (Outslope Grading) Waste rock contouring using a D-8N tracked dozer with a U type blade will require: Average push distance 100 feet • Production rate 900 yd3/hour (unadjusted) • Production rate adjustments for 0.83 job efficiency • Slope adjustment for 30% is 1.8 (3H: I V slopes) • No altitude adjustment is necessary • Operator efficiency (average) is 75% • Material type adjustment (loose stockpile) is 1.2 PRELIMINARY DRAFT FOR DISCUSSION PURPOSES ONLY