Final

Question 1

Provide an expression for the scraper cycle time.

Answer 1

Scraper Cycle time = Load and boost + loaded travel and turn and dump + return travel +
pushcat maneuver time

Question 2

Provide an expression for the pushcat cycle time.

Answer 2

Pushcat cycle time = load and boost + pushcat return + pushcat maneuvering

Question 3

Provide an expression for the balance number of haul units.

Answer 3

of scrapers (balanced to pushcats) = scraper cycle time / pushcat cycle time

Question 4

What is industry practice with regards to the balance number of scrapers - i.e. in terms of
productivity which unit typically governs? - the haul or load unit? Why?

Answer 4

Haul Unit governs if there are more scrapers and Load Unit governs
when there are fewer scrapers. For efficiency, there should be more
scrapers than pushcats (for scrapers are more important and can impede
the process more) therefore haul unit should typically governs.