Kuehl and Payer Ltd. Was assigned the task of setting the control so that construction of the ramp could take place. First KPL set control outside the mine and performed a topographic survey of the area. The next task was to bring the control into the mine which proved quite challenging in that backsight and foresight distances were so short because of the winding nature of the existing ramp that an independent check was needed to make sure an error had not occurred during the descent. An air shaft was found that was located on the surface. A plumb bob was dropped down the center of the shaft some 250 feet and marked inside the mine. The vertical distance was also measured. Vertically the error was about 0.2 feet and because the shaft was not exactly vertical the horizontal component could only be checked for a blunder which was proved not to exist. From this point it was relatively simple to set the control to keep the drillers on the right path from both ends horizontally and vertically.
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