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
