ASSIGNMENTL $1$

A$.$ A rear dump off$-$highwsay truck with a net vehicle weight of $55$ t has been chosen to

haul blasted oxidized $($loose$)$ rock from an open pit mine to a dumpsite through the

road sections given below. Using the performance and retarder charts for Terex $3309$

hauler determine the truck total travel and retum times if its payload is $110231$ lbs$.$

Road Section Length $($m$)$ Rolling Resistance $(\%)$ Grade Resistance $(\%)$

B$.$ A power shovel is to be selacted to load the blasted oxidized $($loose$)$ ore of density

$1\mathrm{.}8t{m}^5$ and a percentage swell of $20\%$ at an hourty production rate of $480m^5.$ The

manufacturer's recommended cycle time per pass for the digging condition is $35$ sec

for a $90$ swing at an optimum digging depth. The dipper fill factor is $0\mathrm{.}9.$ The

anticipated availability and utilization are $0\mathrm{.}98$ and $0\mathrm{.}90$ respectively. Detamine the

dipper capacity of the shovel. $($Note: Approximate answer to the nearest whole

number$).$

C$.$ Assume that the $55$ t Terex $3309$ truck is being considered for selection in a mine that

employs the haul sections given in Q $1$ of length $1\mathrm{.}6$ km $.$ Truchs will be served by the

power shovel in QB $.$ Truck manufacturer recommends that auck should not be loaded

beyond $5\%$ of its design payload of $55$ : It is anticipated that a tuck will have an

sverage sporting time of $0\mathrm{.}5$ minutes, turning and dumping tome of $1\mathrm{.}9$ minutes, and

the payel time obtained in OA $.$ Job operating concitions dictate a productivity factor

of $0\mathrm{.}87.$ The pit is re$$uired to produce $4009$ t of broken rock per hour.

a$)$ Detemine the required trukh fleet if tuck ay alabuiry is expected to be $928.$

b$)$ Determine chovel fleet regured with an availability of $98\%.$