A CAT D&H (power-shift) dozer is used to push material thatweights 87 pcf in the bank state. It is estimated that the materialwill swell 5% from a bank state. The material is in a loose stockpile and is to be moved an average distance of 250 ft on a 2%downhill grade. The operator is average. Job efficiency isestimated to be at a 50-min hour. Assume that the dozer will havean 0.39 coefficient of traction. The O&O cost for the dozer is$86 per hour and the operator's wage is $17.50 per hour plus 44%for fringes, insurance and worker's compensation. Calculate theproduction in bcy per hour. (Reference Table 7.2 and Figure7.13)
TABLE 7.2 Caterpillar job condition correction factors forestimating dozer production
Track-type tractor Wheel-type tractor
Operator
Excellent 1.00 1.00
Average 0.75 0.60
Poor 0.60 0.50
Material
Loose stockpile 1.20 1.20
Hard to cut; frozen
with tilt cylinder 0.80 0.75
without tilt cylinder 0.70 —
cable-controlled blade 0.60 —
Hard to drift; “dead” (dry, noncohesive 0.80 0.80
material) or very sticky material
Rock, ripped or blasted 0.60–0.80 —
Slot dozing 1.20 1.20
Side-by-side dozing 1.15–1.25 1.15–1.25
Visibility
Dust, rain, snow, fog, or darkness 0.80 0.70
Job efficiency
50 min/hr 0.83 0.83
40 min/hr 0.67 0.67
Direct-drive transmission
(0.1-min fixed time) 0.80 —
Bulldozer*
Adjust based on SAE capacity relative
to the base blade used in the estimated
dozing production graphs
Grades—see the graph
