This paper describes an abrasive water jet drill incorporating a collimator, jet deflectors, and an unpressurized swivel. The drill, which utilizes only commonly used pumps, hoses, fittings, and sandblasting abrasives, can drill hard rock such as 73,000 psi compressive strength quartzite with 10,000 psi water pressure. Holes can be collared at any angle or chambered, and drilling can be done through fractured material such as rubble or loose rock in gob areas of mines. Also, because the water jet drill does not physically make contact with the rock, it can be built of lighter materials than conventional drills.
Proc. 4th U.S. Water Jet Conf, Berkeley, California, Aug. 26-28, 1987. ASME, New York, 1987, PP. 129-132