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By S. B. Flagg, J. F. Barkley

In the past few years an awakened activity in power-plant econ- omies has resulted in a marked improvement in the equipment for generating and utilizing steam. Although the improvement in design and construction of steam-driven prime movers has been greater than that of the steam-generating equipment, the economies obtained with the more efficient engines and turbines have stimulated interest and activity in eliminating unnecessary boiler and furnace losses. Much attention has been given to the boiler room in efforts to obtain proper combustion of the coal, because of the importance of the coal item in costs of power production. As evidence of this increasing interest may be cited the record of the development within the past few years of new apparatus for the analysis of flue gases. Many new forms of apparatus have appeared, including those for the determination of carbon dioxide, oxygen, and carbon monoxide, and others for indicating and for recording the content of carbon dioxide only, as carbon dioxide content is usually a good indicator for the control of furnace operation. Because of the large number of steam-power plants operated by the Federal Government and the number of CO, recorders used therein the Bureau of Mines undertook to collect information regard- ing the practical application of such recorders. Articles published from time to time concerning CO, recorders have been mostly descrip- tive, giving little reliable information as to the results that could be expected from the various types of instruments in ordinary prac- tice, and most of the tests made have been of a laboratory nature. Tests of several different types of recorders were made under service and laboratory conditions in order to obtain needed information. The purpose of the Bureau of Mines in publishing the results is to show the factors which may affect the accuracy of a CO, recorder and the manner in which a recorder should be tested. Readers should note that the remarks on different recorders apply to the instruments tested and not to later instruments of the same makers. In the course of the tests the following details were determined: 1. The lag in recording changes of composition of a flowing gas. 2. The accuracy of each type of recorder.

Jan 1, 1916

By C. Lorimer Colburn

"High explosives are generally shipped in stout wooden boxes of convenient size, which are much sought after by miners and others for miscellaneous uses after they are emptied. The management of most mines has no fixed policy for the disposal of used dynamite boxes and will allow any one to carry them away. Many dynamite boxes are nailed up in the mine buildings or underground to serve as shelves and cupboards. Some are used as receptacles for odds and ends, and others are used in taking samples.Although used explosives containers are so generally put to beneficial service, there is nevertheless an element of danger in their use. Dynamite boxes are particularly dangerous. Very often nitroglycerin exudes from the dynamite sticks and is absorbed by the wood of the box. Such boxes are dangerous because they are very explosive. Although a box that has not absorbed nitroglycerin is safe, yet there is always the danger that a person will get a box that is partly saturated.On account of this danger, all mining companies should use extreme care in giving away used explosives containers. Some one individual who is acquainted with explosives and their peculiarities should act as inspector for every container given away. This job may best be handled by the man in charge of the powder magazines. A box that shows any stain of nitroglycerin should be destroyed by fire. The other boxes that are free from nitroglycerin or dynamite can be used."

Jun 1, 1920

By C. E. Saxon, F. E. Cash

"Adequate lighting for all mining operations would unquestionably tend to promote both safety and efficiency; this would be true not only for men but also for the animals that man impresses into service in mines. The Markeeta Coal Co. and the Alabama Fuel & Iron Co. both operating mines in Alabama, have found that equipping mine mules with portable electric lights is more efficient, much more humane, and far more safe for both men and animals then the more or less usual method of forcing the animal to do its work essentially in darkness.This report is intended to give the mining industry data, that will aid in trying to bring about safe and efficient operation of mines.The authors desire to thank Charles F. DeBardeleben, president, Fred R. Bell, general manager, Hewett Smith, C. H. Shepherd, and R. A. Sensing, superintendents for the Alabama Fuel & Iron Co.; and Charles F. DeBardeleben, Jr., president, and H. M. House, superintendent for the Markeeta Coal Co., for their cooperation in furnishing the data for this paper.The eight mines operated by the Alabama Fuel & Iron Co. and one operated by the Markeeta Coal Co. in Jefferson and St. Clair Counties, Ala., are the only mines in Alabama where mules are provided with portable electric lights, and there are few if any mines in other States in which this system is in use.These two companies are convinced that equipping all mine mules with good lights decreases underground haulage cost by animals by prolonging the useful life of the animals, increasing their efficiency, lessening haulage wrecks and delays on haulage, and increasing production. Last but not least of the advantages would be the more humane treatment of the animals.The nine mines are developed by slopes along the dip of the coal bed, with double-room entries on 200- to 300-foot centers turned right and left off the slopes and with approximately 1 per cent grade in favor of the loads. Rooms are driven up or diagonally up the pitch from these entries.A surface hoist delivers the empties from the surface to the entry sidetracks at the slope and pulls the loads to the surface. From these sidetracks, mules pull one to four wooden cars, each of which holds 1-1/2 to 2-1/2 tons of coal, deliver the empties to the rooms and entry faces, and pull the loads to the slope sidetracks. The mule haul varies from 100 to 3,000 feet; there are no locomotives or trolley wires in any of these nine mines, seven of which are rated as gassy and two as nongassy by the Alabama state Mining Department."

May 1, 1933

By John J. Gordon, Neil K. Cooperrider

The International Organization for Standardization (ISO) standard ISO 2631 [1,2] provides three methods for evaluation of human exposure to vibrations that contain occasional shocks or impacts. Part 1 of the standard specifies the running r.m.s. or maximum transient vibration method (MTVV) and the fourth power vibration dose value (VDV). Part 5 of the standard provides a method of computing the stress in the lumbar spine for humans exposed to multiple shocks. Alem et al [3] have reported application of these methods to data for tactical ground vehicles. This paper reports and compares VDV and spinal stress evaluations of more than 90 hours of vibration and shock measurements on North American locomotives engaged in through freight operations. The measurements evaluated in this paper were obtained for full crew shifts on 19 freight locomotive runs on mainline track in locations from New York to California. The shifts ranged in duration from 187 minutes to 497 minutes. The average speeds for the shifts were from 21.0 mph to 54.6 mph. All measurements were made on locomotives hauling freight trains in regular revenue service. Data Acquisition and Processing The results reported here were computed using test data acquired from a tri-axial seat pad, accelerometer at a sample rate of 400Hz with an anti-aliasing filter corner frequency of 100Hz. The VDVs and the lateral and longitudinal spinal stress values were computed directly from the acquired test data according to the procedures specified and described in [1] and [2]. The vertical spinal stress values were computed by converting the as-acquired test data to a sample rate of 160Hz for input to the vertical spine model, as required in [2]. The conversion of the test data from the as-acquired sample rate of 400Hz to the required sample rate of 160Hz involved up sampling or interpolating the test data to an equivalent sample rate of 800Hz, band limiting the resultant data with a low-pass filter corner frequency of 60Hz and finally down sampling or decimating the 800Hz data to a sample frequency of 160Hz. Discussion The vertical VDVs computed according to [2] for the 19 shifts ranged from 2.68 to 9.33 m/s1.75. In all but one case, the vertical values were greater than the values for the lateral or longitudinal directions. Note that the health guidance in [1] puts the lower boundary of the health guidance caution zone at a VDV value of 8.5 and the upper boundary at 17 m/s1.75. The daily equivalent static compression dose computed following [2] ranged from 0.123 to 0.434 MPa. Health guidance provided in [2] states that there is a low probability of an adverse health effect if the daily dose is less than 0.5 MPa.

Jan 6, 2006

By Van H. Manning

Of all the war work by the Bureau of Mines none ultimately covered such a variety of processes and equipment, employed as many men, or called for as large an outlay as that started in con- nection with the solution of problems relating to the use of noxious gases in warfare. Beginning with an investigation to develop the best type of gas mask, the scope of the work extended until it included researches relating to a wide range of devices, such as different types of poisonous and irritating gases and smokes, smoke screens, gas shells and gas bombs, flame throwers, trench projectors for firing gas bombs, signal lights, and incendiary bombs. The Bureau of Mines in starting this work selected the necessary personnel, pro- cured the early equipment, and for some months, from the begin- ning to June 30, 1917, paid the cost of the work from its own funds. The Bureau of Mines built up a research staff of more than 700 chemists, including many of the most prominent chemists in the country, and obtained the cooperation of many of the universities and chemical companies. When the results obtained through this research were to be applied by the War Department, the Director of the Bureau of Mines cooperated in the selection of men to have charge of manufacture or further development, recommending chemiste who subsequently received commissions in the Army. The personal cooperation with the War Department was thus very close. The bureau can fairly claim that because it started this work on gas warfare and received the hearty support of the Department of War, the Navy Department, the National Research Council, and State, educational, and private institutions, the country was in July, 1918, months ahead of where it would otherwise have been in the production of gas masks and other devices. The production of toxic gases then far exceeded the supply of shells. In addition the later work in gas-mask manufacture by the Surgeon General's Office of the Army, which resulted in the development of the best mask produced anywhere; in gas manufacture and gas proving-ground tests by the Bureau of Ordnance, and in the chemical warfare pro- gram of the Navy, including the use of smoke screens, shells and toxic gases, were the direct results of the bureau's experimental work. The American charcoal and soda lime, developed through the research work, are the best used by any nation. The Bureau of Mines was instrumental in developing satisfactory methods of manu- facturing chlorpicrin, phosgene, mustard gas, brombenzylcyanide, cyanogen chloride, and other noxious substances on a large scale. The bureau also developed a smoke funnel for the Navy which no doubt saved many ships from submarine attacks, and devised smoke barrages, signal lights, incendiary darts, etc., for the Army. The Ordnance Department of the Army asked for incendiary bombs and were furnished with bombs better than any made previously. Perhaps the greatest single result of the research work has been the demonstration of the value of the services that the chemist and chemical engineer can render in time of need and the recogni- tion of chemical investigations as a necessary function of the Gov- ernment.

Jan 1, 1919

Oil from shales has long been a source of fuel in foreign countries; however, in the fuel economy of the United States this source is classed as a reserve for future needs. In fad, shale oil has never been produced here in quantities necessary to establish oil-shale utilization as a sustained industry. The first known resources of stored energy that man endeavored to utilize were probably wood and water, and from these he directly obtained heat and power, respectively. With the evolution of man came the search for and the development and use of other natural fuel resources, the series progressing through the solid, liquid, and gaseous fuels until today those of one type can be converted into another, depending upon the use for which they are intended. The most important fuels are those that appear naturally in the most concentrated, conveniently obtainable, and usable forms. With the discovery of each new and more concentrated fuel there has been an appreciable increase in the importance of and number of devices for converting these fuels into energy.

Jan 1, 1938

By Frank E. Cash

The iron-ore ranges in the Lake Superior district are the liarquette in Michigan, Menominee and Gogebic in Michigan end Wisconsin, and the Vermilion, Mesabi, and Cuvuna in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years. During the 4-year period 1940 to 1943, inclusive, 323,667,599 long tons of iron ore was shipped from the Lake Superior district.4/ Michigan and Wisconsin shipped 65,386,608 tons, or 20.2 percent of the total, and employed approximately 15,000 men; Minnesota shipped 258,280,991 tons, or 79.8 percent of the total, and employed approximately 10,000 men. The tons produced per man employed is much, greater in Minnesota than in Michigan and Wisconsin owing to the large open-cut production in Minnesota.

Jan 1, 1945

By John P. Harmon

A group of organic chemicals, known as wetting agents, has been developed, primarily for use in the textile industry. These chemicals have the property of reducing the surface tension of water when mixed with it in very dilute solutions. The advantage of lowered surface tension is recognized in dust-control work, and several wetting agents, have been tried by dust-control engineers with varying degrees of success. It is well-known that certain solids, coal for instance, are extremely hard to wet with plain water because of the high surface tension of water and the water-repellent action of coal. If the surface tension of the water is reduced, it can be demonstrated that the coal can be wetted easily. This is accomplished practical and at law cost by dissolving a very small percentage of wetting agent in the water that is to be used for wetting purposes. (Care should be exercised in using a wetting agent to be sure that it will not interfere with a subsequent process.) For some time, the comparative efficiency of various wetting agents has been the subject of considerable work by dust-control men at coal mines, as well as by members of the Bureau of Mines 3/, 4/, 5/, 6/. In this connection, a number of samples of air-borne dust have been collected in the mines. With the exception of dust-control measures conditions of dust generation and dissemination were maintained as, nearly uniform as possible. Samples were collected when water alone was sprayed on the cutter bar of a mining machine; various wetting agents were then successively added to the water and more samples of air-borne dust were-collected.

Jan 1, 1946

By G. R. Hopkins

One of the largest items in the expense of operating a refinery is the cost of the fuel used in distillation and for miscellaneous purposes such as in the heating of buildings and in the generation of electricity. On a B. t. u. basis, the average refinery consumes approximately one-tenth as much fuel as it produces. Theoretically, the fuel consumption at refineries should be much smaller than this, but furnaces can not be designed to be 100 per cent efficient and, in addition, a large part of the waste heat is low-temperature heat which would not pay for the expense of recovering it. Annual surveys of fuel consumption at refineries have been made by the United States Bureau of Mines, beginning with 1925. During the 5-year period, 1925-1929, the refineries made steady progress in fuel economy. This is evidenced by the computed figures of heat requirement per carrel of crude oil refined, which show a decline from 829,000 B. t. u. in 1925 to 639,000 B. t. u. in 1929 (see fig. 1). In 1930, however, 'the trend in fuel economy was reversed and the quantity of heat utilized in refining the average barrel of crude oil rose to 672,000 B. t. u. There were undoubtedly a number of reasons for the apparent decrease in fuel economy at refineries in 1930, chief of which were the tendency to carry the distillation farther instead of merely topping the crude and a gain in the consumption of waste oils, such as acid sludge, which in actual practice yield less heat per unit consumed than has been theoretically assigned to oil.

Jan 1, 1931

By Joseph L. Condon

High-speed movies were taken of crater experiments in two-dimensional plates of Tennessee marble to study craters being formed primarily by stress-wave action. The contribution of gas action to the cratering process was minimized because the two-dimensional models did not contain the expanding gases from the explosive. Four burdens were studied for solid plates and one burden for a segmented plate. After cratering, the plates were reassembled for dye penetrant studies of fracturing. Flyrock velocities were calculated and related to the degree of fracturing, and compared with those from quarry shots. In general, the smallest burdens produced the highest flyrock velocities and the least amount of fracturing. Flyrock velocities compared favorably with initial flyrock velocities in quarry blasts, but did not show step accelerations due to gas effects as did the quarry blasts. The test with a segmented plate was used to simulate cratering in a jointed material and showed that stress-wave effects can be important for crater formation in jointed rocks.

Jan 1, 1972

By Ramie H. Thompson

1.1 BACKGROUND In many underground coal mining operations the use of electromagnetic field equipment, particularly communication systems, not only increases the overall efficiency of the mining operation but can be directly linked with mine safety considerations. The use of electromagnetic field producing equipment in underground coal mining operations can only be expected to grow. Several new communication systems have already been proposed. In addition, high-frequency producing equipments for many diverse uses in mining operations are under study. The use of these equipment in underground mining operations is hampered by the possibility of their electromagnetic fields interacting with the electric blasting cap operations commonly carried out in the mines. Such interactions can have at least two results bearing directly on mine safety: o premature initiation of the cap, either in its normal shot location or during hookup or transportation; o dudding of the cap so that normal firing operations do not cause irritation; thereby leaving unexploded high explosives after normal firing. Since the consequences of a premature initiation could, particularly in coal mines operations, result in catastrophe involving human life, the overall approach to prediction of possible hazard must be, as far as possible, of a "worst case" nature. The general problem of predicting possible RF hazards for any electroexplosive device (EED) is best treated by reference to Appendix A of

Jan 9, 1983

By John C. Edwards, Gene F. Friel, John J. Opferman, Robert A. Franks

As the use of deep -rut mining increases, there - expected to be a greater demand for methane (CH,) measurement devices capable of scanning working faces al depths in excess of 10 m to alert mine personnel of hazardous concentrations of CH and to satisfy regulatory requirements. Remote optical devices offer the most promise to satisfy these objectives while the operator remains safely under supported roof. A second¬-generation remote Optical methanomeor (ROM) bas been designed and Is undergoing laboratory evaluation at the National Institute for Occupational Safety and Health. It operates on the principle of differential absorption of the "u;' fundamental absorption band of CH, centered at 3.31 um in the infrared region of the spectrum. The new instrument differs from the previous prototypes by the replacement of the two hand pass differential absorption technique of measurement with a single filter gas correlation technique and a refinement of the amplifier and gating circuitry used within the unit. This results in a more accurate isolation of the CH, spectral absorption band centered at 3.31 um. A specially designed 0.4m-diam variable-length gas mixing tunnel was constructed and instrumented with CH4 sampling capability to calibrate the ROM. Experiments have demonstrated the ability of the detector to respond to various conditions of CH, (pn•m) at distances as great as 12 m. Thermal radiation generated within the instrument is the controlling factor in the drift of the output signal nod, therefore the reliability of the instrument. Several approaches to reduce this extraneous radiation interfering moth the infrared detector, described, such as the installation of a fan in the instrument and thermoelectric coolers on the detector's beat sink. Implementation of this technology will significantly improve the safely of miners.

Jan 5, 1997

By Howard M. Stainer

Jan 1, 1963

By Howard M. Stainer

[Cover Page]

Jan 1, 1963

By R. R. Sayers

carbon monoxide mav occur in many places and inhalation of that insidious s is a. frequent and .videly distributed cause of poisoning, ranging in severity from headache and. inefficiency to unconsciousness and death. People are continual­ly being affected by carbon monoxide 1n the home, in garages, around gas and gasoline engines and blast-furnaces, in fighting fires, after blasting in mines and quarries, and after mine fires and explosions; in fact, everywhere there is the possibility of an exposure to the products of combustion of carbonaceous fuels or products, On the other hand, there are arzy' cases reported wherP. ill effects and acci:ients are wro:1gly .ttributed to carbon monoxide. Thus it is essential indeed for doctors, coroners, safety engineers, a.n1 !irst-aid men to be able to recognize this poisoning, not only as reeards giving proper treatment, but to ensure just decisions on claims and to eliminate false illusions and complaints of ·11orkrr.en.

May 1, 1922

By S. A. Gustavson, H. E. Olund

This report has been prepared to review the history of the Premium Price Plan for copper, lead, and zinc, which was in operation from February 1, 1942, to June 30, 1947. It includes various charts and tables comparing costs and production data, and data on exploration premiums that were included in the Plan during the last year of its operation.

Jan 1, 1950

By Frank E. Cash

Large quantities of explosives are consumed in the underground mining of ores in the Lake Superior district. Because of the recognized danger of accidentally releasing the potential highly destructive forces contained, the safes possible procedure in the transportation, storage, and use of explosives is necessary. Underground magazines recently constructed in the district give evidence of the earnest desire of the mine operators to incorporate all possible safe-guards in the storage of explosives, including a careful choice of location and arrangement in the plan of the magazine.

Jan 1, 1946

1. In 2001, a total of 7,131 sand and gravel mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA). Sand and gravel mines comprised 48.8% of all mining operations, the largest percentage of all mining sectors. Sand and gravel mines are distributed throughout all 50 states. The median number of operator employees per sand and gravel mine was 3.0.

Jul 1, 2003

1. In 2003, 14,391 mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA). Almost half (49%) were sand and gravel mines, followed by stone mines (30%), coal mines (14%), nonmetal mines (5%), and metal mines (2%).

Feb 1, 2005

1. In 2003, a total of 4,357 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA). The major industrial classifications in stone mining are dimension stone (used for construction purposes), crushed and broken stone (aggregates), cement, and lime. • Stone mines comprised 30.3% of all mining operations. • Mines producing crushed and broken stone (n = 3,412) comprised 78.3% of all stone mining operations.

Feb 1, 2005