You own a fleet of 30-cubic-yard tractor scrapers and have them hauling between the pit and a road construction job. The haul road is clayey and deflects slightly under the load of the scraper. There is a slight grade (3%) from pit at the fill location. The return road is level. The haul distance to the dump location is 0.5 miles and the return distance is 0.67 miles. Four scrapers are being used. a. What is the rimpull required when the scraper is full and on the haul to the fill? b. What are the travel times to and from the dump location (see Figure 15.10)? c. The scrapers are push-loaded in the pit. The load time is 0.6 minutes. What is the cycle time of the pusher dozer? d. Is the system working at, above, or below the balance point? Explain. e. What is the production of the system?
