Solution Question 3
Excavators
Assume bucket capacity = 3m3
From graph the bulked output of a wheeled loading shovel= 235 m3/ hr
In place output = bulked output/swell factor = 235/1.25 = 188 m3I hr Production losses = 10%
therefore actual output = 0.9 x 188 = 169.2 m3/ hr
Total time required to remove earth = 180,000/169.2 = 1064 hours
Contract time= 8 weeks x 5 days x 10 hours I day= 400 hours
Number of loading shovels= 1064/400 = 2.66 (Use 3 wheeled loading shovels)
Trucks
Truck capacity = 5 x bucket size= 15m'
Loading time = truck volume I bulked production rate = 15/ 235 hours = 3.8 min. Travel time to tip and back = 1.5 miles x 2115 hours = 12 min.
Number of trucks required = 1 +(travel time+ dumping time)
loading time
= 1 +(12+4)= 4.25
4
use 5 trucks per loading shovel
1
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