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By Fred C. Turin, Sean Gallagher, Kim M. Cornelius, William J. Wiehagen

An important part of initiating a site-wide ergonomics evaluation process is prioritizing jobs to be analyzed. While injury data is important, other factors such as worker discomfort and physical exertion requirements, should be considered. This paper describes the use of four sources of data (injury records, the Nordic Standardized Musculoskeletal Questionnaire, supervisor interviews, and management concerns) to prioritize jobs for ergonomic analysis. The approach described integrates the four sources using a decision matrix to prioritize jobs for ergonomics analysis.

By Llewellyn A. Rubin

Under Bureau of Mines Contract H0122007, Telcom, Inc., with the assistance of Fenix & Scisson, Inc., conducted a 17-month research and development project aimed at provid¬ing a field-test model of a guidance system for use with the Bureau of Mines Probe Drill. The Probe Drill is a part of the Bureau's Mine Rescue System developed under Contract H0101262. Volume I of this report is subdivided into seven sections. Volume II consists of a number of supporting appendices. In addition, there were delivered under the Contract, a number of other documents which are referenced in the text. Section 1 deals with essential contract information, Program Background, and a general system description. Section 2 covers the project chronology in brief. Section 3 is a digest of design considerations and implementation related to the requirements of the Contract. Section 4 is a description of the System, including illustrations of the hardware, and software. Section 5 is devoted to Operation and Maintenance. Para. 5.1 describes step-by-step field assembly and disassembly of the downhole unit. Para. 5.2 covers Operation. Para. 5.3 covers various aspects of maintenance from the lowest field echelon possible. Higher level maintenance must be accomplished in the laboratory, for the present field-test model. Para. 5.4 covers system calibration. Para. 5.5 covers detailed step-by-step operational sequences. Section 6 covers the results of the field testing, post-test evaluation, and recommendations. Essentially, we conclude that the present hardware (field-test model) has proven every aspect of system performance, but failed to provide reliable assurance of an operationally ready system. Telcom, therefore, recommends a three-phase continuing effort devised to provide the operationally-ready model of the system.

Jan 1, 1973

By S. H. Lorain

Shortly after the Strategic Minerals Act of 1939 we passed by Congress, the Bureau of Mines was authorized to begin a program of investigation of domestic sources of strategic minerals. Since World War I, the Philipsburg district had been virtually the only one in the United States that was producing manganese on a commercial scale. Consequently, the district was among the first to he investigated. During the summer of 1939, the Geological Survey mapped the geology and ore deposits of the district. In late July 1939 the writer examined the district for the Bureau of Mines. On the basis of this examination and of the work performed by the Geological Survey, the Bureau of Mines diamond-drilled at several properties in the district during the summer of 1940. This report reviews the mining history and geology of the district, and presents the factual data obtained by diamond drilling.

Jan 1, 1950

By Kim M. Cornelius

Musculoskeletal injury is a term used to describe a wide range of soft tissue disorders which affect the nerves, tendons, and muscles. Common examples include lower back pain, tendonitis, and carpal tunnel syndrome. The majority of these injuries are not the result of sudden mishaps, but usually develop gradually from repeated wear and tear. Symptoms may first appear after weeks, months, or even years. Symptoms may result from many types of activities, performed at work or at home, and it is often difficult to attribute a single event. In fact, it is more common to identify the factors which may have contributed to the development of the condition. The terms repetitive strain injuries or cumulative trauma disorders (CTDs) have been commonly used to refer to disorders that have occurred due to work related activities (Putz-Anderson, 1988; Fraser, 1989). Three main risk factors contribute to CTDs: force, repetition, and awkward postures. Any one or combination of these may contribute to the development of CTDs. Therefore, the design of equipment in conjunction with the required tasks should attempt to reduce these risk factors. Examining the layout of the work area to help identify tasks which may contribute to cumulative trauma is necessary. The following list(Putz-Anderson, 1988), describes ergonomic concerns that, overall, should be minimized at the work area:

Jan 1, 1997

By S. J. Schatzel, W. P. Diamond

High methane emissions originating from the active face areas and from the fractured formations overlying and underlying the mined coalbed can adversely affect both safety and productivity in underground coal mines. Since ventilation alone may not be sufficient to control the methane levels in the longwall mining environment, gob gas ventholes have become a standard supplementary methane control option in many mines. As mines progress into deeper and gassier coalbeds, or as longwall panel size increases, ventilation and gob gas ventholes together may not be sufficient to maintain methane levels within statutory limits. To decrease the risk associated with methane emissions under these circumstances, in-seam horizontal methane drainage is often used to reduce the gas content of the coalbed prior to mining. Horizontal methane drainage borehole completion designs, drilling strategies, and degasification lead times may need to be adjusted for site-specific conditions due to mine design, geology, and the gas content of the coalbed. This study investigates different horizontal methane drainage borehole patterns, borehole lengths, and degasification times prior to and during panel extraction to evaluate their effectiveness in reducing methane emissions using a "dynamic" 3D reservoir modeling of a 38 1-m wide longwall panel operating in the Pittsburgh coalbed. Results of this study showed that dual and tri-lateral boreholes are more effective in decreasing emissions and in shielding the entries compared to fewer shorter, cross-panel, horizontal boreholes parallel to the longwall face. Modeling results showed that after 12 months of pre-mining methane drainage, the average longwall face emission rates can be reduced by as much as 10.3 m3/min and 6.8 m3/min using tri- and dual-lateral boreholes, respectively. It was also shown that if pre-mining methane drainage time is short, it is important to continue methane drainage during the panel extraction to maximize reductions in longwall face emissions since additional face emission reductions achieved during this period can be comparable to pre-mining degasification.

By Linneas W. Laage

The purpose of this report is to document the fire experiments conducted at the Waldo Mine, NM during March 1990. The U.S. Bureau of Mines is concerned with improving and validating the predictive capability of the mine ventilation and fire simulator, MFJRE. To accomplish this, fire experiments were conducted at the Waldo Mine and temperature profiles were developed as functions of time and distance from the fire. These tests then provided data for verifying the heat transfer model in the MFIRE mine ventilation and fire simulator. An initial analysis of this data indicates that it will serve this purpose well. This report summarizes the data obtained during six fire tests at the Waldo Mine.

Jan 1, 1994

By J. D. Ramsdell

The purpose of this investigation was to determine the effects of the impurities, oxygen, nitrogen, carbon, and iron (in low percentages) on the mechanical properties of electrolytic titanium. The strength and hardness of binary Ti-O, Ti-N, and Ti-C alloys are linear functions of alloy content in the composition range investigated. Compared to oxygen and carbon, nitro-gen is the most effective strengthener and hardener, followed by oxygen, then carbon. When the carbon concentration is above 0.10 percent, carbides are present, and strength and hardness are relatively unchanged. For equivalent hardness levels, Ti-Fe alloys are stronger than binary titanium alloys containing oxygen, nitrogen, or carbon. However, the strengthening is related to the presence of transformed beta in the structure.

Jan 1, 1960

By D. Ng

A facility to evaluate the fire endurance of mine stoppings was constructed by the Bureau of Mines in the multiple entry section of the Bruceton (PA) Experimental Mine. Stoppings up to 6 by 18 ft can be tested in a manner simulating mine conditions. The stopping is subjected to a 70-min liquid fuel tray fire with an energy output of 75,000 Btu/min. The stopping and adjacent areas are instrumented with thermocouples and heat flux gauges. Data acquisition is by an automatic data logger capable of continuously recording over 100 channels of information. Two 8-in-thick concrete block stoppings and a galvanized steel stopping were tested. A crack developed on the fire side surface of the block stoppings where the flames were most intense. However, the temperatures of the unexposed surfaces of the stoppings never exceeded 800 C and the surfaces were undamaged. The steel stopping retained its structural integrity during the test. The temperature of the unexposed steel surface reached 5000 C, but combustible materials located 1 ft from the surface did not ignite. A 3/4-in-thick coating of construction plaster was applied to the fire side of the previously tested uncoated steel stopping. The quantity of heat energy transmitted across this coated metal stopping was reduced approximately 50%. All stoppings prevented the passage of flame and smoke.

Jan 1, 1988

Simplify the spraying of sealants onto coal mine roofs. Approach A nonclogging system in which dry-fed sealant is mixed with water down-stream of the spray nozzle, has been developed and tested. How It Works The two-channel nozzle of this spray discharges two separate flows, a mixture of air and dry sealant from a central cylinder, and an encircling spray of water from a concentrically mounted water ring (a ring-shaped manifold). Downstream of the nozzle, the water mixes with the air and sealant to form a wet sealant spray that adheres to mine surfaces with very little rebound. (See photograph.) Extensively modified commercial spray machines are used to feed the sealant to the spray nozzle smoothly, without raising dust. Plugging of the nozzle is practically eliminated by two self-cleaning design features of the nozzle. These are the air gap and the tapered bore of the cylinder, (See drawing.)

Jan 1, 1979

The Bureau of Mines has long been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts, the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions1 issued by the Bureau of Mines, and the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. The Government, with the exception of the Tennessee Valley Authority, purchased approximately 5.5 million tons of coal in fiscal year 1971. In connection with these purchases, the Bureau analyzed 4,366 samples. These are published (table 1) for the use of Government officials and the public. Such analyses of delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1972

By M. K. Larson, J. P. Dunford, E. G. Zahl, T. M. Brady

Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health, Spokane, WA, have collaborated with three Western longwall coal mines in an on going effort to develop technologies that will aid in providing safe and stable working areas. The goal of the research described here is to develop a stress monitoring system that will provide immediate information to mine managers for making daily safety decisions as areas of poor ground are mined through. Initial work has focused on answering preliminary questions regarding the reliability and use of stress change patterns. Research is concentrated on monitoring horizontal stress because horizontal stress is transmitted over long distances through stiff strata, thus allowing an extended length of entry to be monitored. This paper presents an explanation of the concept, key results from field tests at two mine sites, and a proposed process for implementing a monitoring system. System design layouts, instrument use, data collection and interpretation methods, and processes to present findings to mine staff are described. Additional validation and correlation with actual failure mechanisms are required before this approach can be recommended at ongoing operations. However, initial results indicate that this approach shows promise in mines prone to bumps and roof falls associated with large stress changes. In particular, analyses of measured changes in horizontal stresses appear useful.

By R. T. Langland

Using a finite-element computer model, we have conducted an analytical study of roof behavior in a room-and-pillar coal mine. With standard engineering property in formation and a computer code developed for the Bureau of Mines to calculate roof sag, convergence, and roof-bolt load change, we have calculated the stability of roof-support systems and compared the computed data with experimental data collected during a field investigation at three test sites, one in a development area and two in production areas of a coal mine.

Jan 1, 1978

By G. R. Hopkins

[Apparent progress in fuel economy at petroleum refineries, as measured by the average amount of .seat units required to refine a barrel of crude oil, received a set-back in 1935, when the average rose to 562,00 B. t. u., compared with 562,000 B.t.u. in 1937 (see fig. l). The primary factor in the rise in average heat requirement's per barrel of crude oil refined in 1938 wan the decline in total runs to Invariably the average requirement increases when crude ins to stills decline, and vice versa. In other words, annual gains in fuel efficiency at refineries arc masked by the degree to which the capacity is utilized. Additional crude runs give lower average e heat requirements in two ways - first, because they are mane with the c expenditure of comparatively small amounts of auxiliary heat, and, second, because the additional runs generally represent simple topping operations. In 1938 crude runs, to stills declined 1.6 percent (from 1,183,440,000 barrels in 1937 to 1,165,015,000 barrels in 1938), but the total heat consumption declined only 0.4 percent, or from 663,866 billion B. t. u. in 1777 to 660, 56 billion in 1938 .]

Jan 1, 1939

By G. R. Hopkins

[Apparent progress in economy at petroleum refineries, as measured by the average amount of hest units required to refine a barrel or crude oil, received a set-back in 1938, when the average rose to 567,000 B. t. u., compared with 562,000 B. t. u. in 1937 (see fig. 1). The primary factor in the rise in average heat requirement's per barrel of crude oil refined in 1938 was the decline in total runs to Invariably the average requirement increases when crude inn to stills decline, and vice versa. In other words, annual gains in fuel efficiency at refineries are masked by the degree to which the capacity is utilized. Additional crude runs give lower average heat requirements in two grays first, because they are mane with the expenditure of cc-comparatively small amounts s of auxiliary heat, and, second, because additional runs generally represent simple topping operations. In 1938 crude runs to stills declined 1.6 percent (from 1,183,440,000 barrels in 1937 to 1,165,015,000 barrels in 1938), but the total heat consumption declined only 0.4 percent, or from. 663,866 billion B. t. u. in 1777 to 660, 56 billion in 1938.]

Jan 1, 1939

By Ellisworth R. Spencer, Lynn A. Alcorn, Peter G. Kovalchik, Adam K. Smith

Noise induced hearing loss (NIHL) is the most common occupational disease among workers in the mining industry. Previous studies conducted by the National Institute for Occupational Safety and Health (NIOSH) have shown that approximately 90% of coal miners and 49% of metal/non-metal miners have a hearing impairment by age 50. The Mine Safety and Health Administration (MSHA) has determined that continuous mining machines rank first among all equipment in underground coal mining whose operators exceed 100% noise dosage. The conveying system is one of the principal noise sources on continuous mining machines, due to metal on metal impacts that occur between chain flights and the conveyor deck. A highly durable polyurethane coating has been developed for the chain flights to decrease noise generated by these impacts. A continuous mining machine retro-fitted with coated flight bars has achieved overall sound level reductions of 5-7 dB in a laboratory setting. This paper evaluates the effectiveness of this engineering noise control in reducing the noise exposure of continuous mining machine operators in an underground coal mine environment. The results show that the operator of a continuous mining machine utilizing the coated flights receives a predicted 35% reduction in total work shift noise dose.

By T. F. Mitchell, J. A. McAllister, S. J. Hussey

"INTRODUCTION During the Bureau's extensive program of investigating possible domestic sources of manganese, an are-dressing study was conducted in its laboratories at Salt Lake City, Utah, on a sample of oxide manganese ore representative of vein material from the Ophir Hill mine at Ophir, Tooele County, Utah. The sample (obtained by blasting down and mixing a portion of the vein) was submitted by the Ophir Development Co. of Ophir, Utah. As the ore was too law in grade to be acceptable for direct production of ferromanganese, it was tested to determine its amenability to concentration by ore-dressing methods.At the beginning of the investigation of manganese-ore beneficiation in December 1940, the only product marketable to Metals Reserve Company was ferrograde manganese, grade B, the requirements for which follow: Mn, min., 48 percent; Fe, max., 7 percent; Si02, max., 10 percent; P, max., 0.18 percent; A1203, max., 6 percent; Zn, max., 1 percent.Later, the specifications were modified gradually. As of May 15, 1943, manganese products were acceptable if they contained over 35 percent manganese and less than 3 percent zinc and 1 percent phosphorus. Prices were based upon material containing 48 percent manganese, 6.0 percent iron, and 11 percent silica plus alumina. Premium were paid for manganese content in excess of, 48 percent and iron content below 6 percent, penalties being imposed upon products containing less than 48 percent manganese or more than 6 percent iron or more than 11 percent silica plus alumina. The specifications for commercial manganese further required that maximum particle size be 12 inches and that 75 percent of the product be coarser than 20-mesh. Therefore, fine material, such as table and flotation concentrates, had to be nodulized or sintered. In addition, carbonate manganese ores were not acceptable unless calcined."

Oct 1, 1947

By Peter F. Steidl

Seven degasification wells have been completed in the Pittsburgh coalbed at the new Emerald mine near Waynesburg, Pa. Funding was provided by the Bureau of Mines to perform stimulation treatments on five of the wells, to show that this is a feasible and economical means of degasifying part of a coalbed. The seven wells ranged in depth from 590 to 910 feet. Stimulation treatments used 25,260 to 42,660 gallons of foam and 7,400 to 12,800 pounds of 20/40-mesh prop sand. Pumping rates were 10.8 to 11.6 bbl/min and treating pressures were from 1,050 to 1,600 psig. On the day following stimulation, gas production ranged from a few hundred cubic feet per day to more than 100,000 cu ft/day.

Jan 1, 1978

By Jack Wasserman, Don Wasserman, Logan Mullinix, Shekhar Khanal, Kelly Neal

This paper presents current finding on truck driver average exposure to acceleration for several different manufacturer’s cab-over trucks on a variety of roads in different countries. The predominant time, for this aspect of the study has been spent in the area around London, England and Warsaw, Poland. The ECE directive 2002/44/EC has provided specific guidelines for vehicle operators 8 hour average acceleration exposure. The primary considerations have been on truck design including the air-ride driver’s seat. The truck manufacturers have produced truck cabs that have some separate suspension from the truck frame. The truck seat manufacturers have been producing air-ride suspension seats for the cab. Both of these designs have had the objective of meeting the ECE directive and providing the vehicle drivers with some degrees of comfort. This paper will provide some information on the ability of the vehicles to operate on a variety of roads and meet the objectives. Method The primary method for evaluation of the driver’s exposure has been the use of a seat pad attached to the driver’s seat. Although this sensor system provides the critical information for the driver, an understanding of the reasons for the values requires additional measurements. The initial study in England used both driver and passenger seat pads, as shown in Figure 1, as well as triaxial accelerometers mounted on the base of the seat. The latest studies used significantly more transducers to better understand the relative rotations and translations on the truck frame, the cab, and the driver. [ ]

Jan 6, 2006

By Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for control-ling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By M. A. Trevits, A. Ozmet, A. C. Smith, J. B. Walsh, T. P. Mucho

Improvements in remote fire fighting technology are needed to reduce miner exposure to the dangers of fires and possibly save the lives of those who may become trapped. The National Institute for Occupational Safety and Health, in cooperation with U.S. Foam Technologies, Inc1., conducted a series of experiments at the NIOSH Lake Lynn Experimental Mine to study the stability, transport, control and fire extinguishing effectiveness of nitrogen-enhanced foam technology. This paper presents a description of the mine test configurations and experimental results