A Hot Water Drill for Temperate Ice,
GEOLOGICAL SURVEY TACOMA WA WATER RESOURCES DIV
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This report describes the development of a high-pressure hot-water drill, which has been used reliably in temperate ice to depths of 400 meters with an average drill rate of about 1.5 meters per minute. One arrangement of the equipment weighs about 500 kilograms, and can be contained on two sleds, each about 3 meters long. Simplified performance equations are given, experiments with nozzle design suggest a characteristic number describing the efficiency of each design, and a minimum bore-hole diameter very close to 6 centimeters for a hot water drill. Also discussed is field experience with cold weather, water supply, and contact with englacial cavities and the glacier bed.