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PETER A. NIELSEN RMCMI PRESIDENT 1991-1992 on behalf of the RMCMI Board of Directors and Officers of The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 88th Regular Meeting and Convention to be held June 28-30, 1992 Tamarron, Durango, Colorado

Jan 1, 1991

Jan 1, 1963

Jan 1, 2009

By J. L. Floyd

The Trapper Mine is a large surface coal operation located in northwestern Colorado US. The coal seams at the mine dip an average of 8 degrees so, historically, their dragline pits have been orien-tated parallel to the dip of the coal seam to balance stripping ratios. However, the mine plan in the future G and Z pits is designed to take advantage of pit orientations that are parallel to the strike of the coal. During the initial presplit and cast blasts in G pit, significant slope damage occurred. This damage included the opening of joints and tension cracking. There was also block movement directly above the L coal seam, which is the main plane of weakness in the slope. A detailed site evaluation was conducted to develop specific blast design modifications to protect the slopes during future blasting. The modified de-signs successfully controlled vibration levels during the blasting of the Z pit box cut. This paper includes a review of the blast vibration related factors that influence slope stability along with a detailed discussion of the field tests and design modifications developed.

Jan 1, 2004

[ALLISON, D. S.. ...................... ,1331 Roberta St., Salt-Lake City, Utah AMBLER, J. B.. ........ c-o Ambler & Riter, Kearns Bldg., Salt Lake City, Utah ANDERSON, A. E.. ................ ,403 Midland Savings Bldg., Denver, Colo. ANDERSON, ARTHUR E.. .. .Colorado Utilities Corp., Steamboat Springs, Colo. ANDERSON, FRANK ........................................... Crosby, Wyo. ANGUS, WILLIAM.. ........... .99 South Downing St., Apt. 204, Denver, Colo. APPERSON, A. B.. ............................ .Tramway Bldg., Denver, Colo. ]

Jan 1, 1928

By George B. Pryde

Dear Sir: Yours of July 23rd, relative to my appointment on the Safety Committee in connection with the Rocky Mountain Coal Mining Institute. As you say in your letter, "The duty of this committee is to draft suggestions as to safer mining practices with the idea of preventing disasters in coal mines." Much has been written and many suggestions made on this same subject, and it is very hard to put up further recommendations than have already been made. The disasters you mention in your letter unquestionably have direct reference to coal mine explosions, which from time to time still occur in this and other countries. As far as our Western mines are concerned, you know that sprinkling and shot firing by electricity have been very extensively carried out. Notwithstanding these precautions; we have had a few rather serious disasters in the past in these mines. I do not care to place any blame or responsibility on the companies having these disasters, but it is a fact that in each and all of them, after careful investigation has been made, that the human element has had more or less bearing on the accidents happening. From most reports that we gain, either directly or indirectly, it is very evident that investigation shows after an explosion that the rules governing one or both of the above safety measures have been somewhat carelessly or negligently carried out. Much has been written and read about rock dust sprinkling, but it is questionable if this method is doing a great deal toward the eliminating of disasters. While it is true it may have the effect of preventing propagation, still I do not believe anyone claims for it a sure preventative against initial explosions. I had occasion not long ago to visit a mine, after an explosion, in which dust barriers were supposed to be hung, and from indications it was quite evident that the dust barriers had been in operation, but they did not prevent the explosion from reaching all open parts of the mine. It is also true that profuse scattering of rock dust throughout a mine would have a beneficial effect, but there is a question arises here as to whether the sprinkling by rock dust or the spraying by water, if available, is the most effective. I am satisfied that if all coal mines are kept well sprinkled and all open workings maintained in a thorough moist condition, that the biggest factor in a coal mine explosion is in this way eliminated. There is no doubt but what the use of permissible powder, particularly if shot by electricity, has had a very marked effect on the number of disasters in mines, and if this method of shooting was energetically carried out there would be a difference in the number of explosions, both minor and Major, all over the country. Some of the recent explosions have taken place where no shooting was being done, but there is no denying the fact that the other ingredient, namely, coal dust, entered in the elements very extensively. We have read and heard of hydraulic cartridges and other patents (substitutes for powder) that were being worked out for the purpose of

Jan 1, 1923

By A. L. Jones

The subject assigned to me of "The Power" Problem of the Mine" is so broad that I have decided to confine myself to the question of the power supply itself, rather than the application of electricity throughout the property. We will look over certain economic aspects of the problem, particularly in the way it affects the mine manager or executive and his attitude toward the power plant. The accepted method of power application to the mine is by electric power, and the experience of each of you is that the job is never complete as you are always undertaking some further electrification which necessitates the stiffing up the power house to care for the additional load. The mine executive, then, is wrestling almost continuously with the problem of his power plant. Either it is overloaded and must be enlarged and rebuilt; or its operating costs are excessive; or it breaks down and limits coal output; or some one wants to sell new and improved machinery, until the manager almost hates the thought of such a restless part of his property. If he purchases power, every day new uses for it seems to be found. In many ways this unrest is due to short-sighted policy toward the problem, and the tendency when the problem of extension has to be met, to dispose of it in the cheapest way and without thought as to where the future is leading. The day when each opening had its own boiler plant, steam hoist, steam driven fans, steam pumps, steam loaders, etc., seems to be far behind us. The recognized method of power distribution today is by electric power, except for rather limited applications of compressed air; most of which is electrically compressed. During fifteen years contact with mines of Colorado and Wyoming the writer has seen nearly every mine power house double or triple in capacity or abandoned in favor of purchased power, worn. out and inefficient machinery thrown out, isolated boiler plants dropped, seam pumping at great depth changed to electric drive, all resulting in greatly reduced labor and fuel costs. Power costs, which in such isolated plants were considered normal, would be unthinkable today. One property where the main power supply was by compressed air from steam driven com¬pressors used under boilers 8.35 per cent of all the coal mined. The cost of power was 12 1/2 cents per ton of coal mined. Another property of four openings, each with its own boiler plant and usual equipment of hoists, pumps, etc., had a power cost of 10.3 cents for each ton mined; and these were days when you did not get very high prices for coal. Another property operating two mines mostly by steam used 11.1 per cent of the coal output under their own boilers and the power cost was 19.45 cents for each ton mined. Each of these properties is now electrified and power costs are from 3 to 4 cents per ton, and the fuel burned runs from 1 to 2 per cent of the output. With the broadening market and high prices for slack coal and the high prices for labor in boiler and engine rooms, the cost of steam is reaching a high figure, and efforts must be made to keep this down, by more efficient steam production and by utilizing this steam in better machinery which will increase the work done by each pound of steam. It must not be overlooked either, that the plant which is very wasteful of fuel is usually a pretty old one and one far from reliable. In a general way the more efficient the plant, the greater its reliability. Ample and reliable power supply means ability to get out coal when there is a market. The increasing use of purchased power is largely due to changing conditions which are tending constantly to push up the cost of power, unless the most efficient machinery is used and large scale production possible. The

Jan 1, 1923

By Bob Burnham

Agenda 1 Overview of forecasting process 2 Review of Pre and Post Recession Forecasts 3 US Demand/Supply Summary 4 Coal Demand by Region 5 Coal Distribution by Census Region 6 Coal Price Outlook 7 Carbon Cases 8 Takeaways

Jan 1, 2009

T. T. READ, BUREAU OF MINES: Mr. McAuliffe has asked a very practical question. Expressed in another way, the question is: If we have decided to use rock dust to prevent coal dust from exploding, have we got to take rock, that is, solid material,, break it up and finally grind it into dust (and fine grinding is very expensive), or can we take material that is already in a pretty fine state of subdivision and thereby save the expense of pulverizing it? Most of the preceding discussion has been from the view-point of practical experience, and I should like to suggest that we have not had enough practical experience in rock dusting to be able to answer this question, from the viewpoint of experience, with the degree of definiteness that Mr. McAuliffe desires. With your permission I will discuss the matter briefly from the theoretical standpoint, because after all the theoretical considerations, insofar as we understand them correctly, will apply to every' case, whereas in coming to a decision on this matter it will be necessary to take into consideration local conditions, which will necessarily vary in every case. Considering the matter in a rather elementary way, the first point is: What makes coal dust explode? The air of this room is full of dust at the present moment, even though we do not notice it. If you were to close up the room for a week, enough dust would settle on the floor so you could write your name on it. Of course, the dust which is in the air of this room is not coal dust but even if it were coal dust and you were to bring an open light in' here we all know that the dust would not explode. The reason for that is that the dust particles are not close enough together for the flame to propagate itself from one to the next. You will probably be able to see in the demonstration in the gallery on Saturday that the coal dust explosion is practically a very rapid burning of the dust. When you light one piece of dust it burns and gives out heat and if there is another piece of dust close enough to it so that the heat from the first piece is able to bring a second piece up to the burning temperature, then the flame will propagate itself through the mixture. But, if the particles are so far apart in the air that the' heat from one particle is dissipated before it reaches an adjoining one, and is therefore not able to bring the second particle up to the burning temperature, then the flame will not propagate. To get a coal dust explosion, it is not sufficient to have coal dust suspended in the air. The coal dust particles must be close enough together in the air so that the heat from one burning particle is able to heat the adjoining particles up to the point at which they will burn. There has been some discussion of the size of dust particles that will cause an explosion to propagate, and it has been pointed out that the minus 200-mesh dust is the most dangerous, and that particles coarser than 20-mesh will not propagate an explosion. There are two reasons for that. A large particle has very much smaller surface in proportion to its weight than a small particle has. You know the old story about the Indian who when asked how he could go around in cold weather without any clothes on said that an Indian was all face. A 200-mesh particle is almost all surface and there= fore is able to burn almost instantaneously, which means that it gives out its heat almost instantaneously, whereas a large particle with less surface in proportion to its weight burns more slowly, gives out its heat more slowly, and the heat has more time to be dissipated. The second reason why coarse dust does not easily propagate a flame is because it is so hard to make it

Jan 1, 1924

By Geo. B. Pryde

Dear Sir: Yours of July 23rd, relative to my appointment on the Safety Committee in connection with the Rocky Mountain Coal Mining Institute. As you say in your letter, "The duty of this committee is to draft suggestions as to safer mining practices with the idea of preventing disasters in coal mines." Much has been written and many suggestions made on this same subject, and it is very hard to put up further recommendations than have already been made. The disasters you mention in your letter unquestionably have direct reference to coal mine explosions, which from time to time still occur in this and other countries. As far as our Western mines are concerned, you know that sprinkling and shot firing by electricity have been very extensively carried out. Notwithstanding these precautions; we have had a few rather serious disasters in the past in these mines. I do not care to place any blame or responsibility on the companies having these disasters, but it is a fact that in each and all of them, after careful investigation has been made, that the human element has had more or less bearing on the accidents happening. From most reports that we gain, either directly or indirectly, it is very evident that investigation shows after an explosion that the rules governing one or both of the above safety measures have been somewhat carelessly or negligently carried out. Much has been written and read about rock dust sprinkling, but it is questionable if this method is doing a great deal toward the eliminating of disasters. While it is true it may have the effect of preventing propagation, still I do not believe anyone claims for it a sure preventative against initial explosions. I had occasion not long ago to visit a mine, after an explosion, in which dust barriers were supposed to be hung, and from indications it was quite evident that the dust barriers had been in operation, but they did not prevent the explosion from reaching. all open parts of the mine. It is also true that profuse scattering of rock dust throughout a mine would have a beneficial effect, but there is a question arises here as to whether the sprinkling by rock dust or the spraying by water, if available, is the most effective. I am satisfied that if all coal mines are kept well sprinkled and all open workings maintained in a thorough moist condition, that the biggest factor in a coal mine explosion is in this way eliminated. There is no doubt but what the use of permissible powder, particularly if shot by electricity, has had a very marked effect on the number of dis¬asters in mines, and if this method of shooting was energetically carried out there would be a difference in the number of explosions, both minor and Major, all over the country. Some of the recent explosions have taken place where no shooting was being done, but there is no denying the fact that the other ingredient, namely, coal dust, entered in the elements very extensively. We have read and heard of hydraulic cartridges and other patents (substitutes for powder) that were being worked out for the purpose of

Jan 1, 1923

PRESIDENT LITTLEJOHN: We have with us a gentleman from Utah, who is familiarly known -as the "Mudite King," Mr. Reid, of the Lion Coal Company. Here is a letter I would like to read, and probably Mr. Reid will give us an idea of his Mudite machine, or the results he is obtaining. This question was brought up in Rock Springs, Wyoming, but Mr. Reid was not there personally during the discussion, but Mr. Burnell, who is general superintendent of the Lion Coal Com¬pany, as much as he possibly could, described the system and its effects. I believe Mr. Reid will probably be able to give a somewhat clearer statement this afternoon. This letter is from the Coal Mining Inspector of the State of Utah, John Crawford. "February 10, 1925. "The Industrial Commission of Utah, Building. "Statement of John Crawford, Coal Mine Inspector, in regard to Muditing in Coal Mines: "That Muditing used in connection with our present sprinkling system in coal mines is the missing link to the system we have had heretofore, because the water applied by the former system began to dry out, in heavy air currents, the moment it was put on. Consequently the dust that had been humidified by sprinkling, came back to its natural condition, and if anything, the combustible parts of it, in my opinion, were more intensified than previous to being wetted down. "The advantages that Muditing has over the old system of sprinkling are: "1st. The dust that is on the roof, timbers and sides of the entry is washed completely off and rolled up in the Mudite solution which entirely destroys the wings, crudely speaking, of the fine coal dust. "2nd. Sprinkling with the Mudite system, the water and mud is of greater extent than could be applied with a hand hose by a sprinkler. This sprinkling can be done while the mine is in operation, just the same as if water alone was being used. "3rd. The Mudite solution, when dried out, leaves a coating which serves as an armour to the coal, so that in the event of a local explosion, the inflammable matter on the coal is non-combustible; whereas, if that same coal had been sprinkled with water only, and made free of dust, the heat would have the same effect on the coal as it has on a stove when coal is thrown into it-instantaneous combustion. "Therefore, it is my opinion that the Mudite system is the missing link to the perfecting of our sprinkling system here in Utah. "(Signed) JOHN CRAWFORD." Mr. Reid has with him a few sam¬ples of his Mudite, after it has become solidified, taken from the floor, as I understand it. It is interesting. We have a few minutes to spare to good advantage, were we to ask Mr. Reid to give us an idea of his machine, as briefly as he possibly can, and also what he thinks the effect of the Mudite is compared to dry rock dust. Mr. Reid. (Applause.) MR. W. J. REID (Lion Coal Company) : I came down here with no intention of making any talk on Mudite. However, there being so many people that have seen Mudite at Wattis

Jan 1, 1925

The eighth annual RMCMI Mine Rescue Evaluation was held during the 1999 Institute convention at the Crested Butte Marriott Resort, Colorado. [ ] Elliott Tsosie, Mary Rowell, Janna Aune, Guy Horton, Art Saenz and Bill Balaz were pleased with the 1999 Mine Rescue Program, The Mine Rescue committee is but one of 17 volunteer committees; this one co-chaired by Bill Balaz, Elliott Tsosie and Janna Aune. There were three evaluators, Art Saenz, Western Environmental; Mary Rowell, ProCare and Guy Horton, Horton Rope Rescue. Nine teams participated and brought 89 participants, 26 spouses, nine children and five teens. The teams were BHP LaPlata, BHP Navajo, BHP San Juan, all from Farmington, NM; Bridger Coal Co., Rock Springs, WY; The Coteau Properties Co., Beulah, ND; Northwestern Resources, Jewett, TX; Powder River Coal Co., Gillette, WY; Solvay Minerals, Green River, WY and Western Energy Co., Colstrip, MT. To observe were members from Centralia Mining Co., Centralia, WA. [ ] Evaluators: Mary Rowell, Guy Horton &Art Saenz The three professional evaluators provided challenging scenarios for the Mine Rescue participants on the grounds of the resort property. Some attending convention were alarmed to see stretchers with "victims" and phoned the hotel switchboard to report the catastrophe. Team members had no prior knowledge of what the scenarios might be and derails were provided only as they arrived at the scenario location, with one exception. Seven to ten or more articipants make up each team. Some teams also ring an alternate and team trainer. For identification purposes, the "victims" wore white shirts emblazoned both front and back with a red VICTIM designation. There was a staged demonstration by three response teams who had not previously worked together. This was enacted on the convention floor following a Technical Session meeting attended by about 200 members. Three response teams from BHP's Navajo and San Juan Mines together with Coteau Properties' Freedom Mine provided a demonstration of their response skills. For never having worked together before, they presented a very professional enactment. This is described at length in the Welcome Session copy. Training sessions were held Saturday and Sunday to enable the teams to prepare for the scenarios. A swap meet was Saturday evening for teams to swap hats, shirts, belt buckles, stickers etc. Each participant received a royal blue golf shirt and ivory cap with royal blue bill. Culmination of the Mine Rescue program was a Tuesday morning Awards breakfast when teams were presented with jade acrylic plaques. [ ] Teams participating in the Mine Rescue Evaluation received trophies on Tuesday morning. The captains above represent BHP-La Plata, BHP-Navajo, BHP¬San Juan, Bridger Coal Co., The Coteau Properties Co., Powder River Coal Co., Solvay Minerals, and Western Energy Co. Sponsors who contributed financially to the 1999 Mine Rescue program were Balaz & Associates, CMC, Civil Constructors, Colstrip Electric, Farmington Fire Equipment & Safety, Fisher Safety, Flanders Ellctric Motor Service, Magnum Metals, Richard Palmtag, Rocky Mountain Electric Motors, Sedona Consulting and Western Water Consultants. [ ] Evaluator Art Saenz likes to have the upper hand and will take whatever steps necessary to get it.

Jan 1, 1999

[JOHN B. MARKS President Boston Bldg., Denver, Colo. BENEDICT SHUBART Secretary-Treasurer 521 Boston Bldg., Denver, Colo. H. H. BUBB Vice-President for Colorado Cokedale, Colo. W. J. REID Vice-President for Utah Wattis, Utah WM. MOORHEAD Vice-President for New Mexico Dawson, New Mexico GOMER REESE Vice-President for Wyoming Frontier, Wyoming EXECUTIVE BOARD COLORADO: E. H. McCLEARY Alamo SAMUEL TESCHER Denver UTAH: DAVE BROWN Storrs JOHN JENNINGS Hiawatha NEW MEXICO: JAS. McDOUGALL Van Houten GEO. MIKSCH Gallup WYOMING T. H. BUTLER Hanna L. A. NORMAN Sheridan]

Jan 1, 1925

DM&E PRB Project [ ] DM&E HISTORICAL MILESTONES ?Start-up in 1986 (former C&NW). ?Colony Line acquisition in 1996 (from UP). ?PRB Project Announcement in 1997 ?IC&E Acquisition in 2002 (former CP/IMRL). ?FRA Federal Refinancing in 2003 (RRIF-1).

Jan 1, 2006

By J. A. Smith

The topic assigned me by the Chairman of the Institute, "Safety Practices in Franklin and Williamson Counties, Illinois," I fear will necessarily resolve itself into a paper on shale dust, its application and the results obtained. I returned .only last week from a three weeks trip through these counties at which time, through the courtesy extended me by the operators, I had ample opportunity to visit and inspect many of the largest mines in the field, some of which are among the largest in the United States. With the exception of shale dust and ventilation, I see but vary few instances where the Illinois mines are further advanced in safety precautions than the western mines, and in some respects I believe the operators of the West are further advanced in safety methods than their eastern brothers. Great care is exercised in handling of all ventilation currents. This is an aboslute necessity, as this field is quite gaseous, and the peculiar geological structure of the overlying and underlying strata makes airtight seals very

Jan 1, 1924

By Wm. Monay

MR. MONAY (Vice President Kinney Coal Co., Scofield, Utah): The past year and a half has witnessed a series of coal mine disasters in Utah and Wyoming, concentrated into the short space of a few months, following a long period of years in which the industry was comparatively free from devastating calamities. The natural result has been a hysterical activity on the part of bureaus, commissions and professional reformers who know little about coal mining from a practical standpoint. This activity has been met by the industry in Utah with an attitude of submission, no doubt the result of the fear of being misunderstood by the public. But it is my firm conviction that the lives and property of the coal industry will find their surest guaranty of protection in the humanity, and in the self interest of those operating and working in the mines, rather than in governmental regulation. Inelastic, inflexible blanket statutes and rules will simply stifle and hamper the initiative and progress of our industry in working out its own salvation, under the varying and changing conditions of different localities, different conditions, and in different mines. We who have spent our lives in digging in the mines and operating them, know more about this business than anyone else and I believe it is time for us to speak up and no longer sit meekly by while inexperienced bureaus and unskilled commissions make up laws, rules and regulations for us which when made are on the books to stay, even though in a short time they may prove inapplicable, in whole or in part, or be superseded by something different, and which in some cases create new dangers or lull us into a false sense of security. Shortly after the Castle Gate explosion in March, 1924, a new set of safety rules was issued by the Indus- trial Commission of the State of Utah to become effective July 1st of the same year, the most important of which prohibits the use of black powder in any mine--gaseous or non-gaseous; prohibits the use of open flame lamps in any mine-gaseous or non-gaseous; and requires that rock dusting in all main haulage ways as far as the freezing point and required that all mining machines be equipped with water to be applied while cutting. These rules have been characterized as "Utah's Monument to her Dead Miners" in a large poster spread broadcast over the country from an office in New York that styles itself the Association for Labor Legislation. In reviewing the coal mining history of the State of Utah, in the year 1900, a serious disaster occurred at Winter Quarters. The cause of the same is believed to be an explosion of powder that was stored in the mine, which was a common practice in the early days, and from that time until the Castle Gate disaster, March 8, 1924, a period of some twenty-four years, no explosion of any kind occurred in this district. During all this period open lamps were used, considerable black powder was used, rock dusting was unheard of, sprinkling with water was very generally done-all without any catastrophe. Since the adoption of the new rules, we have 'had a very violent explosion at the Carbon Fuel mine in Spring Canyon. At the time of this explosion, 3,000 feet of the main slope had been rock dusted several times between July 1st and September 21st. The second left entry, which is a main haulage way, a distance of 3,000 feet was completely rock dusted on the date of the explosion. This mine is not considered extremely gaseous, yet an explosion as violent as that of the Castle Gate mine occurred. Some thirty men who had been loading coal in various parts of the mine on this Sun- day, the day of the explosion, and other men employed in rock dusting the second left entry, had just left the mine a little while before it occurred, and no abnormal condition in the mine was noted. At the time of the explosion five machine men were in the mine.

Jan 1, 1925

By C. P. Crawford

Bureau of Mines Technical Paper 172, by S. H. Katz and H. C. Porter, entitled "Effects of Moisture on the Spontaneous Heating of Stored Coal", says at the outset, "Spontaneous fires in storage piles of bituminous coal' have been the source of trouble and loss since the industrial utilization of coal began. In Europe the idea arose that spontaneous combustion is more liable to happen during wet weather than during dry. Statements favoring or opposing this idea have crept into the literature. Conflicting conclusions, based on experiment as well as opinions based on observations of various degrees of reliability, are given in most of the recorded discussions of the subject. "Because of the uncertainty of the effect of moisture and its seeming importance among the conditions that affect spontaneous combustion in stored coal, the work described in this paper was undertaken by the Bureau of Mines. The experiments showed that a coal from Illinois oxidized faster when dry, whereas a sample of Pittsburgh coal oxidized faster when moist. These discordant results and similarly inconsistent results from the observations of different investigators may be coupled with the fact that under actual conditions of, storing, both coal and air always contain a considerable amount of moisture." The foregoing report of the investigations of the Bureau demonstrates that the mystery of spontaneous combustion has not yet been solved. This fact adds to the fascination of the subject. I became interested in the matter about ten years ago in observing what was probably one of the best exhibitions of this phenomenon. The old dump at Castle Gate No. 1 Mine contained boney coal and track cleanings generally. In winter when snow fell upon this old dump, the snow was soon melted by the heat of the dump which was comparatively warm at all times. Within 48 hours afterward little blue flames were in evidence on the surface of the pile. Few of the gas feeders were sufficiently constant to maintain a steady flame at any given point, but shifting emissions of gas were ignited one by another, resulting in a continuous popping and apparent running about of the flames. Another interesting exhibition of spontaneous heating was to be seen a few years ago in the storage coal piles of the local sugar factories. This coal was piled in concrete lined pits and the latter were filled with water. However, or this occasion the coal extended above the surface of the water. At every plant where this condition existed the coal was affected heating, and in each case the affected area was in a plane horizontal to and from 8 to 1.4 inches above the water level. The height of the hot area above the surface of the water appeared to be affected by the fineness of the coal. It is well known that oily rags have a tendency to heat when allowed to accumulate in some location protected from free air circulation. For some reason, as yet unknown, this does not apply to petroleum or its derivatives. Now, the most common explanation of spontaneous combustion is that the combustible material oxidizes by being brought into contact with air in the presence of moisture, the theory being that the moisture acts as a catalytic agent. My theory is that spontaneous combustion is due to oxidation of combustible matter by free oxygen carried in solution by a liquid, the oxidation taking place only as, when, and at the place where this oxygen is released from solution by the evaporation of the liquid. Also, this oxidation takes place to some degree regardless of the condition of the combustible-whether it be lump coal, coal dust, straw, wheat flour, coke, or any other combustible but, as the speed of oxidation is directly influenced by temperature, it follows that spontaneous combustion only becomes noticeable or serious in cases where the resulting heat' cannot escape as fast as it is generated.

Jan 1, 1925

Jan 1, 1955

By S. W. Farnham

Those who remember the years of patient effort and the slow results obtained in the first introduction of electrical coal cutters and locomotives will, I think, admit that mechanical loading of coal is unquestionably being established at a much more rapid rate than any previous application of machinery to reduce manual labor in mines. There are many operators who consider the progress of the loaders today as slow, but considering the number of years it took to thoroughly establish electrical coal cutters and locomotives, and comparing it with the short time that the mechanical loader has been on the market, and the results that have been obtained today, they will admit, I think, that the progress of the latter is much more rapid. It is about 35 years since the advent of the electrical coal cutter and electric locomotive. Their use has brought about these improved conditions, increased tonnage per mine and other features, which are of assistance to the installation of mechanical loaders. The management and the technical staff in practically all of the American mines are trained in the use of electrical machinery and understand its operation, care and maintenance. . There is frequently, a surplus of electrical power and wiring available to take care of the small requirements of the electrical loader. The mechanical loader, therefore, starts today with the ground prepared for it. Those manufacturing companies who have had years of experience in the design and construction of mining machinery, know in a large measure what to incorporate in their designs to make the parts of the new type of machine effectively strong and to operate with efficiency under the severe conditions encountered in mining service. All these advantages greatly assist the success of a new type of machine such as the mechanical loader. In spite of these advantages, however, there are bound to be some failures. All new types of loaders have to be developed. We hear of some that are a success and some that are set aside. The field of application of each type and its limitations first must be determined by actual operation. The earlier loaders had to be changed and improved in design as weaknesses developed. Not all of the new types of coal loaders have been built by mining machinery manufacturers of long experience, and the lack of experience in this line is responsible for some of the early failures. The coal mining company staffs and also those of the loader companies had to learn what the operating factors were that made mechanical loading a success. The difference in results obtained by loaders in different properties under similar physical conditions indicates that the mine management is a very large, if not the major factor, affecting the efficiency of mechanical loading. Many articles have been written on the question of loading. The subject has been quite fully discussed at recent coal meetings and in the technical press. It is not always as easy or simple a matter to form conclusions as may first appear as to one's own particular loading problem. Mechanical loading is a comparatively new art, and many companies while claiming that loaders are quite successful, do not have an accurate line on the actual saving they are affecting. Many of them have only a few of the factors taken into account in their costs. Many loaders have been generally bought without very careful consideration given to all details and except where extremely favorable conditions prevail, failure resulted. When contemplating the installation of mechanical loading, one naturally desires to select the type of loader that will, fit his mining conditions. The things

Jan 1, 1924

Jan 1, 1960