Chicago : Engineering and Contracting Pub. Co. · leaf 50
lbs.of 40-per cent dynamite. 7X7X30.4 ft. = 1,489.60 cu. ft. broken infirst cross-cut. 13 X 7 X 7.25 ft.= 1,569.75 cu.ft. broken in second cross-cut, or a total of3,059.35 cu. ft. broken in both cross-cuts, or3,059.35 = 247 tons solid broken, which is 12.4 equivalent to 247 X 21.5 = 5,310 cu. ft.,… … Fig. 5—Underground Ore Bin. deep, to furnish an advance of 2.44 ft. perround. Each hole will require 2.88 lbs. dyna-mite, or 43.2 lbs. per round. As it will take.62.5 ft. of holes for one round, the time occu- 4 pied in drilling will be 62.5 X = 6.4, say 39 these, trammed at the rate of one every…
Buildings
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
