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Canadian mining journal January-June 1905 . Steel Derrick for P Drill, on the Rand,Johannesburg, So. Africa. This hole was bored with a Class P steamdrill, rated capacity, 4000 feet. Total running time, 14 months, Size of core, 2 in. for 760 feet, in. for 4,800 feet. Total weight of rods, over 15 tons. On this work a steel derrick, 66 feet in height, asper accompanying photograph, was used, therods being pulled in 50 ft. lengths. Catalogue 49 describes these machines, also smallersizes for any form of power. Air Compressors* Drills, Heavy Hoists, Coal Cutters
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectminesandmineralresou