$8\mathrm{.}12)$ 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 dry clay. It has a unit weight of $3,000l\frac{b}{b}cy.$

The expected rolling resistance for the haul road is $+4\%.$ Assume

a $0\mathrm{.}85-$min load time and an average load of $86\%$ heaped capacity.

Accelerate and decelerate at an average speed of $6$ mph over a

distance of $300$ ft $.$ Use a $50-$min hour efficiency factor. The total

length of haul is $3,400ft$ and has the following individual segments

when moving from cut to fill:

$700ft,+3\%$ grade

$800ft,+2\%$ grade

$1,900ft,0\%$ grade