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By G. S. Morrow, C. D. Litton

This report presents the results of a U.S. Bureau of Mines evaluation of smoke detectors placed in conveyor belt entries of underground coal mines. The selected mines are located in six different Mine Safety and Health Administration (MSHA) districts, are operated by seven different companies, and use atmospheric monitoring systems from seven different manufacturers. Principal concerns are early detection and warning of fires, reliability of operation, frequency of maintenance, and adaptability of detectors to monitoring systems and the mining environment. The data contained in this report provide for some comparisons between smoke detectors and CO sensors, specifically in the areas of early detection of fires and susceptibility to nuisance alarms due to diesel exhaust contaminants. Finally, recommendations for performance standards, sensitivity tests, detector classification, and maintenance are presented.

Jan 1, 1992

By Rimas Pakalnis, Catherine A. Dreesbach, Lewis A. Martin

Instrumented cable bolts developed at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health were used in conjunction with existing ground control systems to monitor rock mass loads at Tg Soda Ash's trona mine, Granger, WY. Axial and shear loads were determined to levels of strain gauge accuracy of ±5 N or ±5 micro strain. These gauges were embedded in a remanufactured king wire that replaced the conventional king wire. Cable bolt performance, quality of grout, and installation techniques were also assessed. By using instrumented cables, a mine operator can determine axial load along the cable at predefined gauge locations. These data provide necessary input for an operator to design a safer working environment for miners.

Jan 10, 2000

By L. J. Prosser, A. T. Iannacchione

From 1991 through 1995, 44 miners out of a total workforce of less than 2,000 were fatally injured in the stone industry. Of these, 12 occurred at underground mining operations with nine deaths resulting from roof or rib falls. A safer environment can be achieved by evaluating the nature of the hazardous ground and by developing more efficient and effective ground-control strategies Roof and rib conditions were observed and assessed in 33 underground stone mines in Illinois, Indiana, Kentucky, Maryland, Missouri, Pennsylvania and West Virginia (Fig. 1). Hazard assessment indicated that the ground failures that occurred under moderate to substantial overburden. i.e., >30 at (100 ft), were caused by stress concentrations and geologic strictures. Ground failures near the surface are caused by solution (water) processes. Selection of the mining horizon and mine-layout decisions tremendously influence ground stability.

By 1980, the U.S. mining community had reached a broad consensus regarding coal pillar design. The pillar load could be estimated from tributary area theory, and the pillar strength from empirical formulas and laboratory coal strength testing. Then the growth of longwall mining required new thinking. Recently, powerful design methods have emerged from analysis of large data bases of real-world pillar successes and failures. These include the Analysis of Retreat Mining Pillar Stability (ARMPS), the Analysis of Longwall Pillar Stability (ALPS), the Mark- Bieniawski rectangular pillar strength formula, and guidelines for preventing massive pillar collapses. Sophisticated numerical models have also helped transform the pillar design landscape. In the process, our understanding of pillar mechanics has been greatly enriched. A new paradigm divides pillar failure into three categories:

By Launa Mallett, Charles Vaught, Jr. Brnich

This paper introduces a technique for incorporating employee participation into the prevention component of a contingency plan. Companies sometimes focus so much energy on response that they forget to put resources into the basics of emergency prevention. The training program discussed here was designed to make employees part of the prevention system. Examples of training materials from the program are provided, a sample method for introducing risk assessment to employees is shown, and a strategy to address limited training time using short videos is explained. Methods for tailoring the training to any worksite and for specific risks are also included. The program is being designed and tested by the Pittsburgh Research Laboratory/NIOSH and employees of an underground coal mine. Examples are taken from the implementation of the program at the mine during the summer and fall of 1998. Results of the program evaluation and lessons learned during the implementation are discussed.

By R. J. Matetic

Researchers associated with the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), are investigating injuries (fatal and nonfatal) attributed to water well drillers during well drilling activities. Injury data, obtained from various sources, suggest that many water well drillers are experiencing unnecessarily high insurance premiums and very avoidable citations or violations from the direct result of accidents, injuries, and fatalities occurring throughout the water well drilling industry. Expensive insurance premiums and unnecessary citations are the direct result of poor health and safety practices. Visits to numerous water well drilling sites were conducted by NIOSH personnel to characterize and identify the injury data collected and to provide inexpensive strategies to prevent, minimize, and eliminate safety and health issues associated with water well drilling activities.

Jan 1, 2001

In Maryland, coal mining is confined to Garrett County and the western portion of Allegany .County. Terrain in both counties is predominately level with rolling hills; state law prohibits surface mining in steep slope areas. The Conemaugh and Allegany geologic formations contain five major minable fields or basins. These include: Upper Youghiogheny, Lower Youghiogheny, Castleman, Upper Potomac, and Georges Creek. Maryland's coal reserves are estimated to exceed one billion tons. Approximately 490 million tons of bituminous coal are considered recoverable using conventional mining methods. After World War 11, deep mining declined in Maryland, and by 1977 surface mining accounted for 91 percent of the total production. Since then, production at underground mines has recovered, accounting for 69 percent of the coal production in 1991. Maryland's permanent regulatory program was fully approved February 18, 1982. Its Abandoned Mine Land Program was approved June 16,1982.

Jan 1, 1992

By Christopher Mark

Australia and the United States both have large, modern underground coal mining industries. Many companies have invested in both countries, and there is growing awareness that technological developments in one country can rapidly affect the other. Yet the ability of technology to pass between the countries depends on comparability of ground conditions. Many Australian observers believe that their ground conditions are significantly poorer than typical U.S. conditions, but some U.S. professionals are not convinced. The author recently visited 10 Australian longwall mines and two room-and-pillar mines. Each mine visit included determination of the Coal Mine Roof Rating, roof support installed, pillar design, and an in-depth discussion of ground control experience. The Australian conditions observed are compared with an extensive data base from U.S. mines. The paper also offers observations on geotechnical data collection, monitoring, and the roles of the mine inspectorate and research community.

By Thomas E. Marshall, Anthony T. Iannachione, Leonard J. Prosser

The location and time of 2,007 microseismic emissions from a limestone mine in southwestern Pennsylvania were compared with the development of mine faces and the characteristics of the mine layout. Based on analyses of these results, the occurrence of roof failure zones appears to be associated with certain characteristics of the mine plan. It was determined that significant relationships exist between the intensity of the microseismic activity and the scale of the roof failures Microseismic activity associated with these roof falls occurs In distinct episodes, with the final failure event occurring during approximately a 12-hour period. Each roof fall episode appears to be composed of dozens of distinct roof beam failures. As each beam fails in shear and tension, tens to hundreds of audible noises representing rock fracturing or bedding plane separation can occur. While every roof fell can be viewed as unique, certain mechanistic similarities can be realized through careful observation and monitoring of these complex systems. Understanding these similarities in characteristics allows mine personnel to design the most effective and efficient control technique.

By G. Molinda, D. Dolinar

Each year, about 2,000 falls of supported roof occur in the more than 800 underground U.S. coal mines. Therefore to help improve the design of primary support systems, the National Institute for Occupational Safety and Health (NIOSH) conducted a nationwide study of roof falls in over 2,500 km of roadways at 37 coal mines. Information on the roof falls as well as other geotechnical, mining, geologic and roof bolting factors were collected and quantified Then a multi variate statistical analysis was conducted on the data with the roof fall rate being the outcome variable The results were used to derive preliminary design guidelines for predicting the roof bolt length, capacity, and pattern required to effectively reduce the roof fall rate. The equations are fairly limited by a relatively high statistical variance in the data. Also reported is a recent survey of U.S roof bolt manufacturers that shows a significant change in bolt types used over the last ten years.

By Jack Wasserman, Don Wasserman, Gretchen Hinton, Logan Mullinix, Shekar Khanal

Human testing has always been a needed way to provide information on the effects of vehicle vibration, however, the manner of testing has not reflected the real situations of driver’s hands on a steering wheel and a seat with back support and driving tasks. The typical system have used a standard sinusoidal excitation rather than the typical types of road – truck excitations The new truck driver training simulators provide the combination of road roughness, speed effects, cab environment and individual tasks. The system has a full six axis simulation potential. The simulators have the protection of the individual by a combination of two ways for the individual to stop the motion as well as an operator with visual capability who can stop the testing. The closed simulator, shown in Figure 1, has the potential for providing motion during the operation.

Jan 6, 2006

Through 1986, Kentucky was the nation's largest coal producer. Currently it ranks third in production, behind Wyoming and West Virginia. Because of the size and variety of Kentucky's coal industry, virtually every kind of surface coal mining and reclamation activity takes place in the state. Extensive coal deposits occur in two separate areas: the eastern coal field, which is part of the Appalachian coal field, and the western coal field. Kentucky's reserves are estimated at 65 billion tons, with 27 billion tons in eastern Kentucky and 38 billion tons in western Kentucky. Kentucky coal is high in volatile matter, low in sulfur and ash, and relatively high in heating value. Coal from Kentucky's eastern coal fields contains a sulfur content of less than 1 percent. Conditional primacy was granted to Kentucky May 18,1982. Since then, all conditions have been removed; final regulatory approval was granted on May 30,1985. The Abandoned Mine Land Program was approved with the regulatory program May 18, 1982.

Jan 1, 1992

By R. V. Ramani, A. S. C. Owili-eger

The Methane Generator program is a part of the Internal Environ¬mental Sub-system of the Master Design Simulator (MDS). All the sub¬systems of the MDS are controlled and activated by the main program as required. The data requirements for the Methane Generator are supplied by the Geology and Reserves sub-system through common storage. Figure 6 shows the information flow between the Methane Generator and other systems of the MDS. It should be noted that the Methane Generator can also function independently as was described under model application. AREAS OF MISSING INFORMATION In any numerical analysis, the accuracy of the solution depends entirely upon the data available. In gas flow problems, parameters that constitute basic model input data are rock porosity, medium permeability, reservoir pressure and initial reservoir pressure dis¬tribution. Unfortunately, however, most of these characteristics are not available for a lot of coal seams. The need for actual field data cannot, therefore, be adequately emphasized here.

Jan 1, 1974

By Leonard Greenburg

The analytical procedure necessary when using this new impinger•bubbler eil)paratus is almost identical with that em:r;,loyed with the Palm0r a:pp8.ratua. As sugar is not employei, the new apparatus por.;sesses the advantage over the eug.r tube method in having vsry low control errors, being, therefore, much simple in laboratory manipulation during analysis.

Aug 1, 1922

By O. C. Blade, E. L. Garton

Louisiana is one of the major oil-producing States of the country. Commercial production of crude oil in the State began in 1902 and has increased to an estimated output of 157,409,000 barrels in 1945, which is the maximum production up to this time and places the State fourth in the nation. The cumulative production for Louisiana through 1944 is 1,544,481,000 barrels, and, adding the output for 1945, the total to January 1, 1946, is 1,681,890,000 barrels. Data on annual production of crude oil in Louisiana and tentative statistics for 1945 are given in table 1. The large production of crude oil in Louisiana and the present trend to utilize petroleum in accordance with its general characteristics make it increasingly important to present analytical data for crude oils. This report is the fifth of a series presenting such data obtained on crude oils from Louisiana according to the procedure used by the Bureau of Mines. Individual analyses are given for 82 samples from 64 fields; many of the samples are from recently discovered fields, and some are from new producing formations.

Dec 1, 1946

The largest producing coal field in Alabama, the Warrior Coal Field, was discovered in 1821'. Since then, coal has become Alabama's leading industrial mineral, both in production and income. Alabama has traditionally been one of the nation's major coal-producing states. This level of production is expected to continue due to Alabama's high-quality, low-sulfur coal. Alabama produces both bituminous and lignite coal. The bituminous coal is mined by underground and surface methods from four major coal fields in 24 counties. Alabama's lignite deposits, which are located in the southern part of the state, are not presently being mined. However, Alabama lignite is high-grade, and deposits are very shallow and easily surface-mined. Alabama gained primacy when its regulatory program was conditionally approved May 20, 1982. The program was fully approved July 5,1984. Alabama's Abandoned Mine Lands program was approved May 20,1982, and its emergency program was approved January 23, 1991. Although a Federal Lands Cooperative Agreement between Alabama and OSM became effective August 30,1985, no coal mining is currently taking place on federal lands in the state.9

Jan 1, 1992

By Jeffrey M. Listak, Gregory J. Chekan

The U. S. Bureau of Mines is investigating longwall panel layouts to maximize coal recovery and minimize interactive problems in multiple-seam operations. When coalbeds are longwall mined in descending order, the transfer of stress from overlying gate roads is a major design constraint affecting pillar stability in the lower mine. The lower mine gate road pillars must be properly designed to withstand the additional load transfer if gate roads are superpositioned in successive seams. The Bureau's MULSIM/NL model, a boundary element computer program, was used to analyze load transfer mechanics for superpositioned gate road pillars. Analysis of Longwall Pillar Stability (ALPS), an empirically based design method for longwall gate road pillars, was used to calibrate model input parameters. ALPS provided a basis to verify model trends and to recommend limits for safe pillar design when superpositioning longwall gate roads. The attributes of the MULSIM/NL model and ALPS were combined to develop a modified method for estimating pillar stress for multiple-seam cases. The modified method uses a multiple-seam factor (MS) to estimate the stress on superpositioned lower mine gate road pillars. Numerical analysis shows that MS depends on the interburden thickness and pillar width.

Jan 1, 1992

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

D.2 Principal Types of Coating A Sodium Silicate Sodium silicate is a good fire retarder when freshly applied, but it loses its effectiveness if the relative humidity is at all high, thus exposure to a relative humidity exceeding 65 percent causes a serious decrease in the effectiveness after only one month. In fire, sodium silicate swells to a frothy mass (intumescence) which hardens and insulates the wood against heat. This property is destroyed by exposure to moisture. Manufacturers of many of the proprietary paints containing silicates state that their products have overcome this difficulty The reagent may be applied alone, or, better, in a mixture with lime-water and common salt, or with inert fillers such as kaolin or asbestos. B Ammonium Phosphate Strong solutions (25 to 35 percent) of monammonium phosphate or diammonium phosphate give good protection. Two or three coats of hot solution should be applied either with a large flat brush or an ordinary paint spray gun The solution should be applied as hot as possible, as this improved penetration, and it should be the aim of the operator to apply 4 lbs of reagent, i e , one gallon of 33 percent solution to every 100 square feet of surface

Jan 1, 1976

By T. E. Marshall, D. R. Dolinar, C. S. Cornpton, L. J. Prosser, A. T. Iannacchione, D. C. Oyler

The U.S., Australian, and United Kingdom coal and the Canadian hard rock mining industries have long recognized the significance of high horizontal stresses as a factor affecting the stability of roof and rib conditions in underground mines. Recently, a growing segment of the U.S. underground stone mining industry has also begun to recognize that horizontal stresses occur in some of its more than 90 mines. Considering the typically high strength and massive nature of limestone, this fact is a revelation in itself. High horizontal stresses produce extensive and sudden rock failures and, in some cases, resulted in injuries to mine workers. Through the years diverse control strategies have been proposed and experimented with. Reorientation of mine entries to reduce stress concentrations have proven successful and are widely accepted in practice. Other solutions, like rock reinforcement, are poorly understood and less accepted in practice. It is the purpose of this National Institute for Occupational Safety and Health (NIOSH) study to develop a better fundamental understanding of these ground control strategies under high horizontal stress conditions through a series of field and laboratory studies. To this end a design technique is presented which provides stone miners with a method for making stability assessments. The consequences of widening rooms, changing geology and horizontal stresses, and different rock bolts on roof beam failures are discussed.

By C. B. Manula, R. L. Sanford, R. A. Rivell

Development of the Rail-Haulage Sub-assembly for the Production Sub-system (UGMHS)* required the use of ,a newly formulated model in order to best satisfy the requirements. Many of the ideas of the former single-stage rail simulator included in the original version of UGMHS have been used, together with the results of experience gained in applying the earlier model to a variety of operating situations (Sanford, 1969). The sub-assembly is developed as an independent system and, as such, can be used to analyze track systems using production distri¬butions as data input. In addition, since this model is designed to replace the original sub-assembly in UGMHS, the linking procedure is identical with respect to bi-directional information flow. The flow of coal from production sections, for example, fills the mine cars, but a condition of "out of empties" or "full of loaded" at a loading station will shut down inby production sections. A requirements analysis was conducted to determine specifically how the model could best serve the user. Operating management had the largest input in developing the following requirements for the Rail Sub-assembly: a) data input in mixed narrative - numeric form to permit user identification of the input variables; b) a user option to extract several ranges of detail in model output, i.e., an average shift summary of minimum retrieval

Jan 1, 1974