Problem $2$

Estimate the total time and cost and the cost per cubic yard for the second balance

point, sections IV and V$,$ of the mass diagram in Figure $7\mathrm{.}9.$ A self loading

scraper with $20$ cy loose measure capacity will be used for the excavating and

hauling.

Assume an average haul speed of $30$ mph and an average return speed of $30$ mph $.$

Use a $3$ min load time and a $6$ min dump time. Assume a $50$ min hour

efficiency and a swell of $25\%.$ The hourly cost of equipment and labor will be:

Scraper $,$$$(65\mathrm{.}40)/($h$)$r

Operator $,$$$(21\mathrm{.}85)/($h$)$r

Foreman $,$$$(27\mathrm{.}20)/($h$)$r