Question $3$

$30$ Marks

A$.$ A slusher is to be employed to handle material in a cut and fill stoping operation. Scraping

over a distance of $30$ m at a rope speed of $76\frac{m}{m}in.$ The operating efficiency of the

slusher is $0\mathrm{.}65.$ The slusher is required to meet a daily production target of $500$ t $.$ The

muck density is $1\mathrm{.}7\frac{t}{m^3}.$ The effective operating hours per day is $7$ hours. Determine the

bucket capacity $(m^3)$ of scraper required for the slusher to meet the target.

B$.$ A $5m^3$ bucket LHD having a rated payload of $9$ tonnes is being employed to load and

haul ore from a room and pillar stope to an ore pass located $250$ m away. The haul profile

with the distances and corresponding speeds in the direction towards the ore pass and

towards the loading point is presented in Fig. $1.$

The loading and dumping times $($including manoeuvring$)$ are $45$ seconds and $35$ seconds

respectively. The operating minutes per hour is $50.$ Two $8$ hr shifts are used for LHD

operation. Determine the daily production rate