Results 81 - 90 of 96

• The Deserado Mine Monitoring and Control System
  7/1/1986 - Conference papers
  The Deserado mine monitoring and control system is a complex system designed to monitor environmental parameters and electrical power, and to operate all types of equipment used in mines, including the entire haulage system.
• Short-Delay Blasting in Underground Coal Mines
  1/1/1986 - Information Circulars
  Research was conducted to determine whether the total elapsed delay time for blasting bituminous coal in underground coal mines could be safely expanded beyond the 500-ms limitation without igniting a methane or methane-coal dust atmosphere.
• A Study of RF Hazards at Low and Medium Frequencies to Blasting in Underground Coal Mines
  9/1/1985 - Contract reports
  Presents the preliminary safe distances for blasting wiring from typical electromagnetic sources. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 mhz.
• Safe Distances for Blasting Wiring from Commonly Encountered Underground Electromagnetic Energy Sources
  9/1/1983 - Contract reports
  The use of electromagnetic field producing equipment in underground coal mining operations can only be expected to grow. The use of these equipment in underground mining operations is hampered by the possibility of their electromagnetic fields interacti...
• Drilling a Horizontal Coalbed Methane Drainage System from a Directional Surface Borehole
  1/1/1982 - Reports of Investigations
  Three long horizontal holes were drilled from a directionally drilled surface hole at the Emerald Mine near Waynesburg, Pennsylvania. The purpose was to adapt the technique of directional drilling for use in draining methane from coalbeds.
• Probability of Encountering Coalbed Discontinuities During Vertical and Horizontal Borehole Drilling
  1/1/1982 - Reports of Investigations
  Probabilities of encountering coalbed discontinuities during vertical or horizontal drilling in a specific coalbed can be estimated based on analysis of mined-out areas of the coalbed where the size, shape, orientation, and distribution of discontinuiti...
• Cableless Electronic Surveying Systems for Horizontal Holes
  9/1/1981 - Contract reports
  The purpose of this project was to enhance the Bureau of Mine's Cableless Electronic Survey System use to aid in the drilling of long boreholes in coal as part of the methane drainage program. The system that was ultimately developed was field tested an...
• Directional Drilling For Coalbed Degasification: Program Goals and Progress in 1978
  1/1/1979 - Reports of Investigations
  The Bureau of Mines is cooperating with the U.S. Department of Energy in a directional degasification project at the Emerald Mine near Waynesburg, Pennsylvania. This project is designed to combine the highly successful underground horizontal degasificat...
• Improved Rail Haulage Communications
  10/1/1978 - Conference papers
  An analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed.
• Directionally Controlled Drilling To Horizontally Intercept Selected Strata, Upper Freeport Coalbed, Greene County, Pa.
  1/1/1977 - Reports of Investigations
  A 3-inch pilot hole was directionally drilled to intercept the Freeport coalbed horizon horizontally at Mather, Pennsylvania, as part of a Bureau of Mines degasification project. The original concept was to continue the horizontal drilling into the coal...