Engineering and Contracting . ed or loosened by a tap of a great saving of bushings and in the costof shanking results when this chuck isused. The machines in use here are .i^ drills, equipped with aiiauxiliary valve, and the 34-in. Holman-air-valve drills. Generally, the Americanmachines were preferred for, as they weremade of better material, they required few-er repairs; no great difference in the speedof drilling was noted. Eleven machinesare used in the shaft bottom. At the Vil-lage Deep shaft twelve machines, riggedon four bars, were used. Here elevenmachin
Engineering and Contracting . ed or loosened by a tap of a great saving of bushings and in the costof shanking results when this chuck isused. The machines in use here are .i^ drills, equipped with aiiauxiliary valve, and the 34-in. Holman-air-valve drills. Generally, the Americanmachines were preferred for, as they weremade of better material, they required few-er repairs; no great difference in the speedof drilling was noted. Eleven machinesare used in the shaft bottom. At the Vil-lage Deep shaft twelve machines, riggedon four bars, were used. Here elevenmachines were sufficient. The hoistingbuckets work in the two compartments, 5ft. long, next the pump compartment. Thepump compartment is 8 ft. long. When the sump or cut is taken out under thetwo hoisting compartments there is a spaceof about 13 ft. at one end of shaft and of10 ft. under the pump compartment bars are rigged, two under the pumpend and three under the two unused hoist-ing compartments. Five machines drill 15. Fig. 2—Simplex Drill Chuck. holes on one side of the cut and six ma-chines drill 18 holes on the other side ofthe cut. If any extra holes should be re-quired there is always a machine that hasfinished its holes, before the machines drill-ing the center holes are through, and it isavailable for the work. The distancesapart of the bars and the arrangement ofholes are shown by Fig, 3. The air is carried down the shaft in a6-in. pipe, placed in the pump compart-ment. A double platform is put in overthe pump compartment and the two unusedhoisting compartments. A cross piece of4-in. pipe, provided with cocks, is runacross the shaft; five hose are coiled onhooks, hanging from the shaft timbers onone end and the other six on the other
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherchicago, bookyear19
