1-Smart Drilling & Hauling company utilizing only experienced drillers. Estimators are working on a project to determine

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1-Smart Drilling & Hauling company utilizing only
experienced drillers. Estimators are working on a project to
determine production for a new project will require drilling and
blasting of high silica granite. Company has drilling experience
with this kind of work and they decided to use 61/2 B downhole
drill at 350 psi. The drills to be used assumed to take steel in 23
ft length. The blasting pattern will be 13x15 . This will require
an extra 3.5 ft of drilling to ensure that final excavation depth
can be achieved. On the average, the specified finish grade is 33
ft. below the existing ground surface. With an assumption of
changing for the drill used 30 minutes downhole hammer and a 40
minute hour efficiency determine the drilling production.