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CASE STUDY-REXROTH still alive. Thus began what would The raise borer vertical rig took time be one of the most thrilling and for arrival and set up, and required Plan B: Bring in the Schramm T130XD technologically innovative mine vertical placement precisely over the At the time of the San Jose collapse, rescues in recent history. The star of location of the miners. When the Plan a Schramm T130XD drilling rig was the rescue was the T130XD mobile A vertical hole was started on August being operated about 1,000 km away, drilling rig from Schramm, Inc. (West 30, the miners had been underground drilling large-diameter bore holes Chester, PA ), for close to a month. It was estimated for water extraction at another deep equipped with hydraulics from that drilling would progress at about Chilean mine site. Bosch Rexroth (Hoffman Estates, IL ). 66 feet per day, and require 80 days to rescue them—if uninterrupted. The T130XD is a heavy duty, heavy hoist carrier mounted drill rig The search for survivors Although they were supplied with food designed to provide powerful drilling Immediately following the collapse, capsules and other supplies through performance in a compact, all-in-one Chile’s government called in drilling the initial pilot holes, estimates of carrier mounted rig. It features a 760 professionals from across the their release ranging from “60 to hp deck engine, and was designed by country, and ultimately worldwide, to 90 days” and “around Christmas” Schramm for heavy-duty deep drilling determine appropriate steps. led to alternative plans for drilling applications with up to 130,000 rescue holes. pounds of pullback capacity. The Examination of the mine’s layout suggested one possible area where survivors (if any) might gather: a mechanics’ room measuring approximately 538 square feet - the equivalent of a small apartment - situated 2,300 feet down. Drilling a bore hole that deep, with that level of accuracy for the endpoint, was compared to “hitting the head of a pin with a 20-foot pole.” The mining authorities were also concerned with the local geology: it was known that granite structures at the site were at least 20 percent harder than granite typically found in the U.S. Drilling consistency would be varied, with densities ranging from low to very high. developed by the Chilean authorities focused on using a complex drilling rig called a raise borer from another manufacturer, to drill a vertical rescue hole. The initial rescue plan, called “Plan A,” Schramm’s T130XD mobile drilling rig, equipped with Rexroth AA11VLO pumps. www.ghmediabusiness.com Multiple rescue plans 37