www.gyrodata.com Updated June 2018. Copyright © Gyrodata, Inc 2011 A large mining producer of polymetallic resources, located in central Peru, needed to install an elevator shaft that would transport workers between the ground level and the secondary level. Adding an elevator shaft would save the workers up to 4 hours of travel time by eliminating the need to travel around the mountain to reach the mine shaft entrance. The new elevator shaft required a 121/4" diameter pilot hole drilled to a depth of 477 m while staying within a 1 m radius to accommodate the 5 m diameter hole enlargement during the raise boring procedure. Additionally, due to the hard rock formation, the drilling system would need to operate at very low rotary speeds utilizing loss circulation material (LCM). ? T

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