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Appendix A: Method of Estimating the Flow from a Drill Hole <br /> Mr. Bob Ward (mine superinten0ent during construction of the American Tunnel) supplied the <br /> following estimates of conditionsil concerning the drill hole intersection of the Washington vein: <br /> The drill hole was appro�imately 41/2 feet above the floor, <br /> The drill hole was 2 inches in diameter (BX bit), <br /> The hole was drilled at an upward angle of 7 to 8 degrees from the horizontal, and <br /> The water hit the floor approximately 20 feet from where it left the drill hole. <br /> From the above information an estimate can be made of the rate of flow of water from the drill <br /> hole. The flow from the drill hole dropped to the floor due to 1) an initial downward component <br /> of velocity resulting from the angle of the drill hole, and 2) the acceleration of gravity. <br /> The loss in elevation caused by the angle of the drill hole (assumed to be 71/2 degrees) is <br /> Elev. = (20 feet) _ cos (71/2 degrees) = 2.63 feet <br /> Hence, the loss in elevation caused by the acceleration of gravity is: <br /> 4.15 feet - 2.63 feet = 1.87 feet, <br /> where 4.5 feet is the initial height above the floor. <br /> sanjuan\sunny\110361\oct9 1.Rpt A - 2 <br /> a simon <br />