Blasting a New Entrance to Carroll Cave
Carroll Cave, located in Camden County, in south central Missouri, is one of the most significant caves in Missouri with over 12 miles of mapped passages and over 100 known but unmapped side passages. In the early 1990's there was a breakdown of the originally excellent landowner/caver relations as the ownership of the only known entrance moved to a new generation and grottos squabbled for control. Subsequently the current owner of the natural cave entrance refused to grant anyone permission to enter. The Carroll Cave Conservancy has leased land over the cave from a cooperative landowner and has been working to dig a new entrance. A sinkhole dig was started in November 18, 1995 and was reluctantly abandoned after five years and over 1000 man-days of digging, due to safety concerns. Subsequently a pilot hole was drilled down into the cave to passage junction point 4 hrs travel from the cave entrance where the going gets easy. After successful break through on the first drill hole an attempt was made to jackhammer down to the cave, however the massive limestone encountered made this impossible. In fall 2001 the University of Missouri Rolla Mining department and UMR ISEE student chapter members were recruited to assist the conservancy in the blasting of a 30 inch shaft down 120 ft from the surface to the cave below. The shaft was being blasted around the 9-inch pilot hole. A blast pattern was designed to break the rock from the shaft into small enough pieces to allow the debris to fall into the cave to eliminate the risk involved with hauling muck to the surface and to ease the burden of the work. The project was demanding both physically, mentally and from a planning perspective. Special attention was paid to the safety of the operation and the protection of the cave below. All the work was volunteer and supported by money raised by the conservancy and donations of equipment and material. The paper and presentation discuss the work and methods used to successfully tunnel down to the cave.
J. Bowles et al., "Blasting a New Entrance to Carroll Cave," Proceedings of the Annual Conference on Explosives and Blasting Technique, International Society of Explosives Engineers (ISEE), Jan 2003.
Twenty-Ninth Conference on Explosives and Blasting Technique
Mining and Nuclear Engineering
Article - Conference proceedings
© 2003 International Society of Explosives Engineers (ISEE), All rights reserved.
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