$8\mathrm{.}9$ Based on the scraper specifications in Table $8\mathrm{.}1$ and the performance charts in Figures $8\mathrm{.}8$ and $8\mathrm{.}9,$ and for haul conditions as stated here, analyze the probable scraper production. How many scrapers should be used and what will be the production in bcy per hour? The material to be hauled is cohesive. It has a swell factor of $0\mathrm{.}77$ and a unit weight of $2,940l\frac{b}{b}cy.$ The expected rolling resistance for the wellmaintained haul road is $+4\%.$ Assume a $0\mathrm{.}85-$min load time and that average load will be $89\%$ of heaped capacity. To account for both acceleration and deceleration, use an averase speed of $5mph$ over a distance of $200ft.$ Use a $50-$min hour efficiency factor. The total length of haul is $2,500ft$ and has the following individual segments when moving from cut to fill:

$600ft,5\%$ grade

$1,700ft,2\%$ grade

$200ft,-4\%$ grade