$(50$ points$)$ The GX mine uses sublevel stoping mining method. The LHD

data, truck data, and operational data are given below

LHD Data:

LHD bucket capacity $=2\mathrm{.}7m^3$

LHD Tramming capacity $=5\mathrm{.}44$ tonne per cycle

LHD availability $=85\%$

Bucket fill factor $=85\%$

Material $($blasted$)$ loose density $=2\mathrm{.}78$ tonne per $m^3$

Loading time plus round trip between draw$-$point and dump location

$($stope entrance$)=2\mathrm{.}5$ minutes

$($note: this time includes interaction with other LHDs in the system$)$

Dumping time $=0\mathrm{.}4$ minutes

Truck Data:

Payload $=20$ tonne

Truck haulage profile: $550-m$ in level drift, then $1450-m$ in decline at

grade $=10\%$ to surface, $200-m$ at a level haul road to processing plant.

Truck speed profile: loaded $=16\mathrm{.}1km$ per hour at level road and $6\mathrm{.}4$ km

per hour at road with grade $=10\%$; Empty $=20\mathrm{.}3km$ per hour at level

road and $15\mathrm{.}8$ km per hour at road with grade $=10\%.$

Truck dumping time $=0\mathrm{.}40$ minutes

Truck turning or manoeuvring time $=2\mathrm{.}51$ minutes per cycle

Operational data:

Required production $=4500$ tonne per day

Production shifts per day $=2$

Working time per shift $=12$ hours

Truck driver expected efficiency $=85\%$

a$)(6$ points$)$ Calculate the LHD payload and determine if it match the tramming capacity.

b$)(8$ points$)$ Calculate the LHD cycle time.

c$)(4$ points$)$ Calculate the number of LHDs required to meet production demand.

d$)(10$ points$)$ Calculate how long it takes for the LHD to load one truck

e$)(10$ points$)$ Calculate the truck cycle time in minutes.

f$)(6$ points$)$ Calculate one truck production per day.

g$)(6$ points$)$ Determine the number of trucks to meet production demand.