Chapter 10 (trucks and hauling Equipment)

What is added to an articulated truck to increase load capacity?

a retainer plate

what is the loader production equation? (used if at least 1 extra truck is used)

(60/loader cycle time)x Bucket Vol.

What is the truck production equation (used if fewer than the balance number of trucks are used)

(60/truck cycle time)x truck volume x number of trucks

List the 10 steps in the truck production process

1. # bucket loads 2. load time 3. haul time 4. return time 5. dump time 6. truck cycle time 7. number of trucks required 8. production 9. efficiency 10. cost

List the truck production steps

1. load with exchange 2. haul 3. dump and maneuver 4. return

What is the equation for haul time (both haul and return use same equation.... step 3 and 4)

=distance (ft)/88xHaul speed

What type of dump trailr deposits a wind row of material?

Bottom Dump

What are the 3 typical dump times used?

Favorable-0.3 min Average-0.6 min Unfavorable-1.5 min

What is the cycle time equation

Load time+haul time+dump time+return time

What is the equation for Load time (step 2)

Load time=excavator cycle time x No. bucket loads

What is one major factor in selecting haul units?

distance

Does operator efficiency increase or decrease as haul distance increases to around 8000 feet, after which it remains constant?

increases

What is key to keep the fleet running?

maintenance

If at least 1 extra truck is used, what controls production

the loader

what is the equation for number of bucket loads required to fill the truck? (step 1)

truck capacity/loader bucket capacity Round up = full load round down=short load

What is the trucks required equation? (this equation gives the balance number)

truck cycle time/loader cycle time

what is bunching?

with a perfect loader and hauler match, the effect of bunching is a 10%-20% production loss. Extra trucks reduces production losses by always having a truck waiting to be loaded

Can articulated trucks operate over soft ground?

yes