|
Equipment |
Components |
Comments |
|
Excavators / shovels /loaders / backhoes |
- Operation cycle
- Cycle time
- Cycle rate (cycles/hr)
- Cost ($/hr)
- Capacity (bcy)
- Maintenance
- Operations checks
|
Load-swing-unload-swing back cycle
Actual bucket load = fill factor * shovel capacity
Cycle rate = cycles / hr
Operational cost = cycles / cycle rate * cost
|
|
Trucks |
- Operation cycle
- Cycle / travel time
- Cost ($/hr)
- Capacity (bcy)
- System production (bcy/hr)
|
Load-travel-dump-travel back to excavators cycle
Cycle time = travel time * 2 + load time + unload time
Operational cost = cycles / cycle rate * cost
System production, P = capacity / load time (bcy/hr)
|
|
Trucks - ascending / climbing up slope |
- Rimpull curves - relating effective resistance, weight, Rimpull force, speed
|
Effective resistance = slope % + friction %
Choose laden weight of truck load
Read off gear, speed
Determine ideal cycle time
|
|
Trucks - descending / travelling down slope |
- Continuous grade brake retardation curves - relating weight, speed, effective assistance
|
Same as Rimpull, but
Effective assistance = slope % - friction %
Friction reduces the favourable acceleration from down slope
|
|
Equipment-ground contacts |
|
Good resistance to rugged conditions
Maximum friction
Limited speed
|
|
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Good flotation on soft surfaces
Some speed
Some friction
|
- Small, high-pressure tires
|
Maximum speed
Some friction
Poor resistance to rugged conditions
|