Question

A 240 hp (power-shift) dozer is used in pushing operation. The dozer is equipped with a straight blade. The

material (dry and noncohesive) weighs 98 pcf in the bank state. It is estimated the material will swell 6%,

from bank to loose state. The center-of mass-to -center-of-mass pushing distance is 195 ft. Job efficiency

can be assumed to be equivalent to a 50-min hour. Calculate the production in bcy per hour and the direct

cost of the proposed earthmoving operation in dollars per bcy. The company’s normal O&O cost for these

machines is $92.00 per hour and the operator’s wage is $18.00 per hour plus 35% for fringes, insurance,

and worker’s compensation. Show all the required calculations

Answer 1

Ans: - To calculate the production of the 240 hp dozer. productionſ icy per 60-min ho ] a = nel-hp x 330 D+50 Here Net hepp is the net hosse power at the fly wheel for . a power - shift dozer D : one -way push distance in feet substitute 240 too net up and 195 Ft for one-way push distance - 240X 330 323.2 leyl hy 195 + 50 cient calculate the mateval weight consection cosechi factor convent the bank weight of the materials from Ibleeft to 16lcu yd as below Bank Weight (16 I cux) = Bank Weight (lblfeet) x 27 cuft)euyd substitute 98 lbl cu ft too bank weight (lb I feet) Bank Weight (lb) cu yd) - 98 1bl cu feet x 27 cu feet leu Yd = 2646 161bcy calculate the soll density cootechion factor:- Bank weight in ) bey soll density it swell percentage 1 2646 1b/bcy fo bank weight and 6% for swell percentage soil density correction = 26461b/by to.ob 24146.22 15lcy convechion - Substitute

calculate the material weight confection factor :- material weight correction factoo - standand condition soil density cosection substitute 2300 lb/bey for standard condition and 2496022 bley for soil density confection material weight covechton factoro - 2300 - 0.92 2496.22 the calculate efficiency efficiency coopection coorection factor = factor ebticiency B0 min-hr efficiency = Gomin Elfciency coorection fador = 5o = 0.833 GO calculate the dozer production as followe Do 2.0 pooduction = Qx material weight lossection factor x effcierry fa It swell percentage Q = 323.2 1cylny material weight factor = 0.92 efficiency - consection faction = 0.833, bot. fs swell percentage 323.2% 0.92 x 0,883 Dozer procluction 247.7 1 +0.06 1.06 = 233.767 b cyn I Dozer production = 233.70 boylar/

calculate the total cost as follows :- Oando = 42 operaloo = 4:18 +0.35 (18) - 24:3 total cost = cand o cost + operator cost 92 + 24.3 -1116.3 calculate costo the cast per day as follows por bey = total cost production total cost = $116.3 poodlucion = 233.76) cost per bay = $116.3 2.33.76 bc ylhr =$0.497 1bcy. .: the cost pos bay = 0.497 [bey |