Basically we will determine “how many hauler we need to serve one loader”, to maximize productivity unit (BCM/hour). The determination depend of :
- Materials condition will be load (good, average, rather poor, or poor)
- Bucket capacity loader (BCM)
- Cycle time loader /phase or /swing (second)
- Vessel capacity hauler (BCM)
- Hauling distance (m)
- Grade of road (%)
- Haul road conditions
Productivity Loader
Productivity = ( 3600/D ) * A * B * C BCM/Hour
Note : A = Bucket capacity loader (BCM)
B = Bucket factor, depend materials condition will be load :
B = 1.01 if good (clayly soil, clay, or soft soil)
B = 0.90 if average (loose soil with small diameter gravel)
B = 0.85 if rather poor (well blasted rock)
B = 0.75 if poor (poorly blasted rock)
C = Job efficiency, depend materials condition will be load :
C = 0.90 if good
C = 0.85 if average
C = 0.78 if rather poor
C = 0.75 if poor
D = Cycle time loader /phase (seconds), can determine from manual book unit or directly observation on the bench.
B & C are specific number, depend of area & operator conditions.
Productivity Hauler
Productivity = A * B * C BCM/Hour/Unit
Note : A = Vessel capacity hauler (BCM)
B = Vessel factor, depend materials condition will be load :
B = 1.01 if good (clayly soil, clay, or soft soil)
B = 0.90 if average (loose soil with small diameter gravel)
B = 0.85 if rather poor (well blasted rock)
B = 0.75 if poor (poorly blasted rock)
C = Rate or trip /hour
Rate or Trip /hour = ROUNDUP ((60/A) * B) rate or trip /hour
Note : A = Cycle time unit hauler /trip (minutes)
B = Job efficiency, depend materials condition will be load :
C = 0.90 if good
C = 0.85 if average
C = 0.78 if rather poor
C = 0.75 if poor
Cycle Time Hauler = A + B + C + D + E minutes
Note : A = Loading time (minutes)
B = Loaded travel time (minutes)
C = Dumping time (minutes), depend of dumping area conditions :
C = 0.90 if favorable
C = 1.00 if average
C = 1.25 if unfavorable
D = Empty travel time (minutes)
E = Spotting time (minutes), depend of loading area conditions :
E = 0.10 if favorable
E = 0.15 if average
E = 0.20 if unfavorable
A, B, and D are specific numbers, depend of area & operator conditions. It can determine with formulations or directly observation on the bench.
Loading Time = ( (A * B) * E )/60 minutes
(C * D)
Note : A = Vessel capacity Hauler (BCM)
B = Vessel factor, depend materials condition will be load :
B = 1.01 if good (clayly soil, clay, or soft soil)
B = 0.90 if average (loose soil with small diameter gravel)
B = 0.85 if rather poor (well blasted rock)
B = 0.75 if poor (poorly blasted rock)
C = Bucket capacity Loader (BCM)
D = Bucket factor, depend materials condition will be load
D = 1.01 if good (clayly soil, clay, or soft soil)
D = 0.90 if average (loose soil with small diameter gravel)
D = 0.85 if rather poor (well blasted rock)
D = 0.75 if poor (poorly blasted rock)
E = Cycle time loader /phase or /swing (seconds).
Loaded Travel Time = A / (V * (1000/60)) minutes
Note : A = Hauling distance (m)
V = speed loaded travel (km/hour)
Empty Travel Time = A / (V * (1000/60)) minutes
Note : A = Hauling distance (m)
V = speed empty travel (km/hour)
To determine speed in travel time, have many factor or very complex, so need many raw data in directly observation. Then we make average speed.
Match Factor
Match Factor = (A * B) / C
Note : A = Productivity hauler /unit (BCM/hour)
B = Number of hauler to serve one loader
C = Productivity loader (BCM/hour)
If Match Factor > 1 is over truck/hauler, so we must use productivity loader to budgeting and scheduling.
If Match Factor = 1 is ideal condition, we can use productivity loader or hauler to budgeting and scheduling.
If Match Factor < 1 is less truck/hauler, so we must use productivity hauler to budgeting and scheduling.
If You want the calculating above in excel format, You can email me at dani_prastiadi@yahoo.com.
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