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By L. C. IlsLey

One of the details which the engineers observe closely in conducting tests on explosion-proof type equipment at the Pittsburgh experiment Station of the Bureau of Mines is the construction of covers and their means of fastening. These covers are of particular concern from a safety standpoint, because they are very liable to be frequently disturbed for the purpose of making inspection or repairs to internal parts of motors, controllers, etc. When depended upon to permit frequent inspections it is desirable from a practical operating standpoint that the cover be easily and quickly removed and replaced. The position that been taken by the Bureau of Mines is that the questio of ease with which covers will permit inspection should be determined by the mamu- facturer and the user. If the scheme used requires considerable effort, as in the removal of several bolts, it has been assumed that the one going to all this trouble to get the covers off could be trusted to put the cover back in place properly, especially as the approval plate generally calls specific attention to this point. Where a cover is simply screwed in place, fastened by a single bolt, or secured by a hing in or other similar arrangement, the bureau has not been willing to assume that the, cover would in all cases be properly fastened and has required further security by means of a lock or seal. In the course of its investigations the bureau has had occasion to inspect and test five types of covers as follows: (1) Covers having two plane surfaces bolted together. (2) Covers having two plane surfaces held together by lugs, clamps, or other means besides bolts. (3) Covers which have screw thread and fit a similar thread in the compartment. (4). Covers having plane surfaces with the addition of a tongue-and-groove joint at about the center of the plane surface and in general secured by hinge pins or similar means of fastening. (5) Covers in the form of an annular ring accurately fitted to a motor shell which can be rotated around the shell, and thus make easy access to inspection openings in the shell and rotated back again to effectively seal these openings. Tests. have also been made of large bolted covers having a smaller and more accessible cover within the large one, which could be opened for inspection purposes.

May 1, 1930

Reduce permanent hearing losses to bulldozer operators. Approach Two types of noise control packages have been developed, that can be readily fabricated and installed into bulldozers by mine personnel. How It Works Both of the noise control packages reduce the noise exposure of the operator by two techniques, blocking the noise paths or absorbing the sound before it reaches the operator. Both airborne noise paths and noise paths through the machine are blocked. One noise control package is designed for bulldozers having ROPS (Roll Over Protection System), but no cab. The other package is designed for bulldozers having ROPS

Jan 1, 1981

By John G. Kovac

A computer simulation has been developed by the US. Bureau of Mines to estimate the chances of a miner making a successful escape while wearing a self-contained self-rescuer (SCSR). The model takes into account (1) training in the use of SCSR's, (2) apparatus integrity, and (3) oxygen cost of a mine escape. This report examines survival odds for a prototypical escape, and illustrates how these odds change when SCSR training is improved.

Jan 1, 2009

By C. W. JEFFERS

During the past few years the use of mechanical equipment for the loading and transportation of coal at the working face has rapidly increased . Many mining officials are of the opinion that mechanical methods have tended to reduce the hazards of mining, and a number of statements have been made to this effect . Little actual data upon which to base conclusions in regard to the relative safety of various methods of mining have been made available . While it may be possible that these systems of mechanical mining are inherently less hazardous , obvious dangers should not be disregarded in the belief that the mere act of installing mechanical loading equipment automatically brings about better accident records . The same rules and regulations , modified to meet the new regime must be applied with the same discipline as heretofore . By diligent study and application there is reason to believe that new methods of concentrated mining can be utilized with at least a possibility of increased accident performance . With the idea of preventing accidents by taking available precautions against their occurrence , attention should be directed to the dangers that exist where room and face conveyors are in operation . Due to the cost pressure prevalent in the mining industry at the present time mechanical means are often used in an attempt to decrease cost of production. The management , after having spent considerable sums of money for new equipment , is expected by stockholders and investors to show results by increasing tonnage and reducing operating costs . Consequently the operating officials apply the same pressure to local mine officials to obtain results . The natural reaction of the superintendent and mine foreman is to secure the maximum production from the new method , and unfortunately safety is frequently , if not generally , sacrificed to this end . In many instances , operators of new types of mechanical loaders are difficult to secure and after being obtained are difficult to hold , especially if the new equipment is more or less in the experimental stage . The tendency is to handle the machine operators with " gloved hands " and to permit many unsafe practices which ordinarily would not be allowed, in order to keep from antagonizing them and losing their services . Although these unsafe practices become habitual and even uneconomical , conditions thus established are difficult , sometimes impossible , to change .

Jul 1, 1930

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Jan 1, 1997

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

This report describes the development and application of a rail haulage simulator that is readily adaptable for the analysis of a wide variety of operating problems. Various gaming, options have been integrated into the model structure which permit trial and error solutions from a computer terminal prior to capital committment in the actual operation. The high level of information retrieval available allows engineers and managers to develop production data which fit individual needs. In this report, emphasis was placed on the problem of organizing and performing the sequence of operations that are necessary to accomplish a complete mine materials handling simulation. Here, the Rail Haulage Sub-assembly was linked to the Production Sub-system to mine and move coal from seven operating sections to the intermediate and main-line track. The analysis was devoted to the problems associated with how the operating system performs and what alternatives were available to minimize idle times and hence increase productivity. In order to have some objective means of evaluating which of the alter- native methods for production was most appropriate, the choice was to replace the intermediate track with belt conveyors. Since the attempt here was to demonstrate model flexibility and not to establish the goals or trade-offs between computing objectives with which systems judgement must contend, no further alternatives were tried. This is left to management with the data and a problem to solve. Rail haulage simulation is not new, and several, operationally tested models are being used in practice (Bucklen, et. al., 1968).

Jan 1, 1974

By D. Harrington

Examination of numberous disasters , such as fires or explosions , and the evidence at coroner's inquests following such disasters in several States , have shown the writer how frequently men in charge of the operation and safety of mines have forgotten, or have failed to learn , details of safe mining practices , After securing a position of trust as superintendent , or a certificate of competency to act as shot -firer , fire boss , or mine foreman, some men seem to have felt it unnecessary to keep safety principles in mind , or to keep abreast of current progress in safety ; they have concentrated on getting out maximum tonnage at minimum cost . • In coroner's inquests , the testimony after disasters has shown that firebosses , foreman , and coal -mine superintendents are noticeably lacking in knowledge of the provisions of the State mining law relating to fans or doors , frequency of crosscuts , nature of stoppings necessary , electrical equipment , records of daily mine examinations , quantity of air required , or splitting and overcasting .

Jul 1, 1922

Wires leading to or from underground facilities can develop hazardous voltages because of lightning exposure. The locations of many mine portals are particularly susceptible to lightning effects. The application of protective devices to limit this potential danger is necessary.

Jan 1, 1975

By David S. Yantek

A-weighted sound levels around vibrating screens in coal preparation plants often exceed 90 dB(A). The National Institute for Occupational Safety and Health (NIOSH) is actively developing noise controls to reduce noise generated by horizontal vibrating screens. A 121-microphone, 3.5-meter-diameter array was used to perform beamforming to determine locations of significant noise radiation on the screen. Below about 1 kHz, the screen body was found to be the most significant noise source. The beamforming contour maps showed several key locations on the sides of the screen and the feedbox are the most significant contributors. Operating deflection shape (ODS) analysis was used to examine the screen behavior under actual operating conditions. This information is helpful in determining how to modify the screen body to reduce the noise radiated by the screen below 1 kHz. The analysis showed modal vibration patterns on the sides and feed box were the main contributors to noise. The results show several areas on the screen sides and feedbox that can be modified to reduce noise.

Jan 1, 2009

By J. M. Stuve

A novel calorimetric solution technique, recently developed at the Bureau of Mines, was tested using synthetic samples of chalcocite (CU2S) and covellite (CuS). The solution of these refractory sulfides was accomplished by oxidation with bromine in a moderately acidic, aqueous solution. The resulting values for the standard enthalpies of formation (?Hf°, 298.15) for CU2S(c) and CuS(c) were -18.1 ±1.1 kcal/mol and -13.3 ±1.1 kcal/mol, respectively. These values are in good agreement with published formation values derived from other methods of physicochemical measurement.

Jan 1, 1982

By Thomas C. Miller, Rudolph Sporcic

A relatively simple and inexpensive encapsulated hydraulic device has been developed by the Bureau of Mines to facilitate study of coal bumps , and to measure pressure changes in a coalbed as it is subjected to roof loading during mining . Construction of the device and application techniques are described . Preliminary feasibility tests in the laboratory and field indicate that the device responds satisfactorily to pressure changes in coal created by roof loading .

Jan 1, 1964

By J. M. Mutamansky

"Coal mine dust research throughout the world has been stimulated by the recognition of its importance in the development of coal miners' diseases, particularly coal workers' pneumoconiosis (CWP). A historical look at the problem and the present state of knowledge in this area of importance to the worldwide coal industry is presented. A summary of progress made in this area is provided and some research ideas for the future are discussed.1. INTRODUCTIONI thank Dr. Yong Won John, President of the Korean Institute of Mineral and Mining Engineers, for his invitation to address the International Symposium on Coal Mining and Safety. This presents me with an interesting opportunity to take a broad look at the research in coal mine dust and where we are going. From this broad perspective, we can all view the progress and problems that are apparent in the present state of knowledge of coal mine dust. One important element in the review of coal mine dust research and its role in miners' diseases is that of its history. The existence of diseases attributed to the mine atmosphere is often traced back to Pliny the younger in the first century A.D. His work on natural history mentioned observed human effects attributed to mine fumes and vapors. However, the subject of the effects of dust in the mine was not mentioned in published literature until 1556 when Agricola discussed the ailments of miners in his day (Seaton 1975).For many centuries, many medical ailments of the lungs were often categorized together and distinct diseases were often not recognized until more modern times. The ability to distinguish different lung diseases was limited until the discovery of X-rays in 1986. Nonetheless, Zenker in 1866 applied the term pneumonokoniosis to any disease where dust gathers in the lymphatic depots of the lungs. This term was changed to pneumoconiosis in 1932. While pneumoconiosis was defined in the 1800s, scant attention was paid to control of miners' diseases until recent decades. The first attempt to control disease through control of the mine atmosphere has been attributed to the South Africans who instituted a silica control in 1910 (Drinker and Hatch 1954)."

Jan 1, 1989

By Roy H. Grau

The National Institute for Occupational Safety and Health (NIOSH) has conducted research to improve the ventilation of large-opening mines whose entries are at least 93m2 (1,000 ft2). The ventilation of large-opening mines is unique compared to other types of mines because (1) it is challenging to keep airflow velocities high enough to effectively remove or dilute airborne contaminants because the entries are so large, (2) large air volumes can be moved through the mines with little static pressure drop, and (3) stoppings that are used to direct ventilation airflows are costly to construct and to maintain. The research results suggest that the ventilation of large-opening mines is improved significantly by incorporating ventilation planning into the mine planning process, using propeller fans to direct airflow, developing new stopping materials and construction methods, and using long pillars to eliminate crosscuts where possible.

Jan 1, 2009

By S. B. Robertson, D. R. Dolinar, G. E. Hinshaw, G. M. Molinda, D. M. Pappas

Rock falls in coal mines cause many injuries each year. Most of these injuries are not caused by major roof collapses, but from falls of smaller rocks from the immediate top or roof skin. Even though safety professionals and mine operators strive to reduce these types of injuries, there has not been a substantial decrease in the rock fall injury rate over the past decade. Various surface controls are used in mines to control the roof skin. One control that has proven to be very effective is roof screening. Roof screen effectively controls roof skin and provides a high roof surface coverage. Although many mines are reluctant to use screen for primary skin control because of the additional costs of time and materials, others are having great success at controlling both the costs and surface rock. In this study, injury data are presented that show a dramatic reduction in roof skin injuries when screening is used. Much of this success is due to the protection from falling rock that the operators receive from roof screen. Five case studies in which roof screen was used are presented along with the associated costs of materials, impact on bolting advance rates, and potential ergonomic risks. The effects of roof screening on skin control and safety are also included. Finally, this paper provides information about best practices and features of roof bolting machines that affect production and safety.

By Travis Q. Lyday

Ecuador's economy continued to slow in 1982 due, in part, to declining foreign demand for oil, depressed world oil prices, and high international interest rates. Real growth of the gross domestic product (GDP) was estimated to be in the 2% to 3% range, down from the revised 4.3% recorded in 1981 and the 4.5% anticipated officially. In current prices, the GDP in 1982 was estimated at $12.1 billion.2 Inflation abated slightly from that of 1981 to an estimated 13.9% annual rate. The sucre was devalued in May by 32%, the first time in more than a decade, as a result of the pervasive flow of capital abroad. Ecuador's production of petroleum increased an estimated 1.9% in 1982 compared with that of 1981. The consortium of Corporación Estatal Petrolera Ecuatoriana (CEPE), the state oil company holding a 62.5% interest, and Texaco Inc. (37.5%) produced an estimated 98%, or approximately 211,000 barrels per day, of the total from the northern part of El Oriente, the eastern jungle region, where a Texaco-Gulf Oil Corp. partnership discovered oil in 1967. Gulf subsequently sold out to CEPE in 1977 for $117 million, Remaining production was from the Santa Elena Peninsula Fields on the Pacific coast where production has been steadily declining for several years.

Jan 1, 1984

By Gerrit V. R. Goodman, Charles D. Taylor, Edward D. Thimons, Jay F. Colinet

The importance of controlling respirable dust and methane gas levels in underground coal mining cannot be underestimated. While respirable dust can significantly affect the occupational health of underground coal miners, methane gas accumulations pose significant safety concerns for these same workers. Water sprays and machine mounted dust scrubbers offer effective control of respirable dust exposures and methane gas accumulations. Water must not only be applied carefully to avoid dust rollback to the machine operator but must create sufficient turbulence to remove dead zones that could contain high concentrations of methane gas. While the flooded-bed dust scrubber has been generally responsible for decreased worker exposures to respirable dusts, this device has proved effective in controlling methane levels at the face. This paper reviews practical applications of water sprays and dust scrubbers to control respirable dust and methane gas on continuous miner faces.

Jan 4, 2000

By Kathleen M. Kowalski-Trakofler

This paper discusses human judgment and decision making under stress. The authors review selected recent literature across various disciplines and suggest a definition of stress within the context of decision making during the management of emergencies. They also discuss fieldwork by the Pittsburgh Research Laboratory, NIOSH, which explores traumatic incident stress, the relationship between previous training and performance under stressful conditions, and human behaviour in underground mine fires. The authors assert that stress is one of the factors that decision makers must contend with in most life-or-death situations. They suggest that a better understanding of individual judgment and decision making activities whilst under stress would yield a better understanding of how people reach the choices they make in emergencies. This enhanced understanding would be of enormous value to emergency managers, researchers and policymakers.

Jan 1, 2003

This report was prepared by Jacob Tolsma and Arnold N. Johnson of the Uniroya 1 Research Center, Wayne, New Jersey. The valuable assistance and suggestions of the project officers, Mr. Ronald D. Hill, Dr. David R. Maneval and Mr. John J. Buscavage is gratefully acknowledged. The authors are grateful to the following Uniroyal personnel: Mr. Daniel Shichman, manager of Engineering Research, and Dr. Emmanuel G. Kontos, manager of the Polymer Physics Research for their direction, encouragement and suggestions regarding the experimental work, and Mr. Mark Olson for the design of the hollow auger soil sampler. We also wish to gratefully acknowledge the efforts and contributions of ideas proposed by our consultants, Dr. Frank T. Caruccio, assistant professor of geology at State University College, New Paltz, New York, and Dr. Pa Ho Hsu, associate professor of soil chemistry, Rutgers University , New Brunswick, New Jersey.

Jan 1, 1972

Are you afraid of the dark? Of course not, at least not since you were about six years old, anyway. But early man was - afraid of the dark, and he had good reason to be. Since he had no illumination other than fire and moonlight, he was at a disadvantage when it came to mixing it up with some of his fellow creatures. Sabre-toothed tigers, for example, could probably see quite well In the dark, and they were very real enemies. Sabre-toothed tigers haven't been seen in mining country for some time now; but it's st111 dark In a mine and, make no mistake about it, there are still enemies in the dark. The enemies are all the things that can injure you if they are not seen. Modern mines can be safe places to work for the trained miner who follows good work practices. But there are mining machines that make sabre- toothed tigers look like pussycats, and if you can't see well enough they can be ten times more dangerous.

Jan 1, 1976

Develop a curved ray geotomographic program with constraints to counteract non-uniqueness in order to improve the reliability of seismic tomographic imaging of geological structure in mining regions. Background Seismic tomography provides a two-dimensional image (tomographic reconstruction) of the distribution of the seismic velocity in geologic structures using measured travel times of seismic waves crossing the area. It can provide a more complete representation of features be¬tween boreholes than other crosshole processing methods that measure only average properties or borehole logging methods that measure properties only near each borehole. Seismic tomography has many mining applications. They include locating geologic structures of contrasting seismic velocity, detecting fractured regions where the seismic velocity is low, and monitoring solution injected above the water table where the increase in saturation increases the seismic velocity. Thus, tomographic imaging techniques show great promise for detecting and locating geologic hazards that affect the productivity, safety, and environment of mining operations.

Jan 1, 1992