Problem:
A contractor wants to investigate the production and cost differences of using a 7S blade on a D7H dozer or an S blade on an 824 dozer. The material is a dry clay, and it is to be moved a distance of 300 ft from the beginning of the cut. The dozing is downhill on a 5% grade. The operator will have average skill, the dozers have power-shift transmissions, and traction is assumed to be satisfactory. The site will be dusty. The material weighs 102.5 pcf in the bank state and has a 18% swell percentage. Job efficiency is assumed to be equivalent to a 50-min hour. Calculate the direct cost of the proposed earthmoving operation in dollars per bcy. Assume that the O&O cost for the D7 dozer is $175.00 per hour and $155.00 per hour for the 824. The operator's wage is $55.00 per hour plus 30% for fringes, workman's compensation, and other benefits.