Trends and Topics Case Studies Mobile drilling rig equipped with Rexroth hydraulics frees Chilean miners Challenge: Rescue 33 miners trapped in a gold mine collapse, using Schramm Inc.’s advanced T130XD mobile deep drilling rig to drill a 28-inch wide hole 2,300 feet through solid granite. Rexroth Solution: Four Rexroth AA11VLO130 variable displacement axial piston hydraulic pumps: Open circuit pump with charge pump Nominal pressure 5100 psi (350 bar) Peak pressure 5800 psi (400 bar) Displacement of 130 cc/rev. or 7.93 in3/rev. Rexroth Results: High displacement capacity and proven reliability support the T130XD’s performance Rexroth pumps power the top head and master cylinders of the drilling system—to manage thousands of feet of drill pipe Schramm rig originally designated as “Plan B” quickly turns into the primary rescue solution Three-month estimate of original drilling rescue timeframe was reduced to 33 days All 33 miners recued safely Download the complete case study (PDF - 553 KB) More on Rexroth Variable Displacement Pumps. Mining a Miracle The whole world watched as Schramm Inc.’s T130XD mobile drilling rig, with hydraulics powered in part by Rexroth AA11VLO130 Variable Displacement Pumps, dramatically rescued 33 trapped Chilean gold miners in record time. On Aug. 5, 2010, a cave-in occurred at the San Jose gold and copper mine near the northern city of Copiapó, Chile, trapping 33 miners in a chamber about 2,300 feet below the surface. After waiting 17 days, an exploratory drill broke through to where they were, and they attached a message telling the world they were still alive. That began one of the most dramatic and technologically challenging mine rescues ever attempted. At first, due to the depth where they were located, and the dense granite of the location’s geography, it was estimated that drilling a rescue hole would take four months -- “around Christmas” was the best guess. Schramm’s T130XD mobile drilling rig, equipped with Rexroth AA11VLO pumps (image courtesy of Schramm, Inc.) The reliability of Rexroth AA11VLO pumps is especially critical in deep drilling applications At the time of the San Jose cave-in, a Schramm T130XD drilling rig was being operated about 1,000 km away, drilling large-diameter bore holes for water extraction at another deep Chilean mine site. A key technology of the hydraulic system that powers the drill is the Rexroth AA11VLO130 Variable Displacement Pumps. Schramm selected the AA11VLO1030 pumps when designing the T130XD because of their proven performance, particularly in deep drilling applications requiring the high pressure capacity and 130,000 pounds of pullback pressure delivered by the T130XD. The Rexroth AA11VO Axial Piston Variable Pump is designed for hydrostatic drives in open circuits. It offers high power capacity and displacement in a compact design, with nominal pressure of 5100 psi (350 bar) and maximum pressure of 5800 psi (400 bar.) Within a few days, the T130XD was on site at the San Jose mine, working as one of several drilling rigs attempting to bore a hole wide enough to lower a rescue capsule down into the mine and bring the men back to the surface. The story of how the T130XD significantly reduced the time it took to complete the drilling and rescue the 33 miners was one that captivated the world in late 2010. Learn how advanced drilling technology, including the Rexroth hydraulic pumps, enabled the miracle in San Jose. Download the complete case study (PDF - 553 KB)