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By Lloyd Garrison

The Garrison Automatic Domestic Stoker is a device intended primarily for residences and small apartments. In the development of the device com- [ ] mercial features have been given as much consideration as have engineering features. As a result of this consideration the stoker is well within the reach of the middle class buyer as regards price, while at the same time it possesses all of the features of comfort, economy and convenience which accompanies this type of stoker. The stoker is of the over feed type and uses the natural draft of the furnace. A 1/12 H.P., 1,800 R.P.M., motor drives a small worm gear unit through [ ] grooved pulley and rubber belt, effecting a speed reduction from 1,800 to 6 R.P.M. The gear shaft drives a slide situated in the bottom of the coal hopper that causes the coal to be deposited on a link belt chain which carries it through a trough and drops it on the grate. Use of a screw feed has been purposely avoided because of

Jan 1, 1925

By Robert M. von Storch

Chairman Doc, distinguished guests, and fellow members of the Rocky Mountain Coal Mining Institute: It's a genuine pleasure to meet with you again at the 54th regular meeting. I might add that it is always pleasant to be at the top of the batting order. The field is wide open since there is no danger of repeating something already said. At the same time, I am aware that the lead-off speaker has a responsibility to avoid stepping on the toes of subsequent speakers. I promise to confine my remarks to areas other than those to be covered by the well qualified speakers that follow. During our meetings at this convention, many fine papers will be presented. Our thanks are due Bob Williams and his hard working program committee for the superior selling that brought so many eminent speakers to our meeting. And, of course, our special thanks go to Doc Schloss, general chairman of this meeting. Doc and his able colleague, Stan Shubart, have been the spark plugs that fired up all of the arrangements we are enjoying here in Glenwood Springs. I'm sure all of us are appreciative of the many hours Doc has devoted to seeing that our meetings will be pleasant and profitable. When we mention arrangements, we always think of that master arranger, Fred Whiteside, who, as a charter member and secretary-treasurer of the Rocky Mountain Coal Mining Institute, has had more to do with more matters around these parts than just about anyone I can think of.

Jan 1, 1958

D. HARRINGTON: Owing to lack of funds, the United States Bureau of Mines have made no experiments in the Bruceton mines in the use of mudite. MR. McAULIFFE: I doubt that mudite cam be delivered at fifty cents a ton and that a mile of heading can be treated with mudite for ten dollars. You could not dig a ton of sand out of a sand hank for that money. L. C. CLARE: The tram road leading to Wattis mine crosses a shale bed and it is easy to screen the shale through a %-inch sieve and load it into a mine car. W. J. REID: A slow trip passing through a mudited entry will dislodge practically no dust, a rapid trip will make air disturbance enough to coat the cars with fine dust. MR. PRYDE: We have used mudite on stoppings around a fire in Reliance and for two months thought they were getting good results, but the fire was found to be drawing air and to be spreading. This mudite was smeared over the stoppings with a trowel. After this apparently failed we used dry adobe.

Jan 1, 1925

Earl W. Baker W. P. Bigler Lyman Fearn Leslie H. Johnson V. O. Murray Max C. Scheble Fred L. Smith who left the world better for their having lived in it . . .

Jan 1, 1986

[Page Officers of the Institute 5 Minutes of Twenty-first Meeting 9 The U. S. Fuel Company's Tipple at the Hiawatha Mine John M. Jennings 11 Some Experiences With Mechanical Loading in Central Pennsylvania¬ O. G. Sharrer 13 Mechanical Loading Underground- A. W. Dickinson 25 Operation by Long-Face Conveyor Method at Sweetwater Mine Glen A. Knox 39 Discussion of Mechanical Loading 44 Discussion-Safety in Mechanical Loading 45 New Steel Tipple, Spring Canyon, Utah- G. A. Murphy 46 A Theory on the Cause of Spontaneous Combustion-C. P. Crawford... 48 Rock Dusting in the West-D. Harrington 50 Mudite-L. C. Clare 57 Discussion of Harrington's and Clare's Papers 59 Material for Rock Dust-Prepared Discussion-Edward K. Judd 60 Tipple and Mine of the Columbia Steel Corporation-T. C. Harvey 63 Mechanical Stoking of Domestic Fuel-Joseph Harrington 67 The Garrison Automatic Domestic Stoker-Lloyd Garrison 70 Discussion of Domestic Stokers 71]

Jan 1, 1925

By Geo. A. Murphy

MR. ARTHUR E. GIBSON (General Manager, Consumers Mutual Coal Company of Utah) : I suppose the reason I was called upon to read this paper was because I was at the mine for several years, but I have not been there for the past four years and the installation has been put in since I left. This article has been written by my successor-it follows: At the very urgent solicitation of your Secretary I have consented to prepare this paper descriptive of the spiralizing plant which is a part of the new steel tipple recently erected by the Spring Canyon Coal Company to serve its mines at Spring Canyon, Utah. I have been reluctant in giving this consent for two reasons: one of which is an excellent one, and the other isn't any good at all. First,, I find that it takes a long time to become familiar with the eccentricities of spirals-to get wise to their whims and peculiarities, and while this plant has been in operation for a number of months, something new seems to crop up nearly every time I see it, and -it would be impossible to describe all of these things even if I remembered them. The second reason is, purely personal. Among the many things I have learned by attending the sessions of the Rocky Mountain Coal Mining Institute is that if a man is not pretty sure of the ground he attempts to cover, he had better keep his mouth shut, because if he isn't right, he is dead sure to be called down by someone. However, as I will not attend the session, this feature will not hurt much, but it will make it necessary for someone else to read the paper and this will make it much better for those who are obliged to listen to it because I don't read English very well. To begin with I will say that what is said in this paper applies only to the plant under discussion as I have had no experience with any other plant. While spirals have been in use for quite a number of years, and there are some large plants in the East, their use has not been general, and I believe the plant at Spring Canyon is the only one in the United States west of the Mississippi River. The details of the plant were worked out by Mr. Thos. R. Stockett, General Manager of the Spring Can= yon Coal Company; it was manufactured by the Anthracite Separation Company of Hazelton, Penn., incorporated in the design and erected by the Link-Belt Company of Chicago, in connection with the balance of the tipple. It consists of five units. Each unit consists of a vertical wood column about 6 inches in diameter, and 9 feet 6 inches in height, around which the spiral is built. It is something like a triple screw conveyor, set vertically, with flights down which the coal and refuse travel by gravity in the process of separation. There are three of these flights, forming a sort of nest but about 7 inches apart, and they make 21 turns around the column in its length. These flights dip toward the column about 27 degrees; they have a uniform pitch downward of 31 degrees; they are 19 inches wide at the top (measured from the column) and taper gradually until they are about 9 inches at the bottom. They are not made with one continuous plate from top to bottom, but are made up of a number of plates. Some of these plates are slightly waved, others have small corrugations in them and still others are perforated with small holes, all of which are intended to accelerate or. retard the movement of the coal and refuse as they pass down, At intervals there are adjustable plates in the flights for the purpose of decreasing the maximum outside;

Jan 1, 1926

The following is the list of those who have become charter members of the Rocky Mountain Coal-Mining Institute COLORADO Adamson, W. H., mine examiner, Leyden Coal Co., Leyden. Addison, Herbert, vice-president, Big Horn Collieries Co., Denver. Allen, Carl A., assistant professor of mining, Colorado School of Mines, Golden. Alley, Gerald, chief draftsman, Fuel Department, Colorado Fuel & Iron Co., Pueblo. Anderson, A. E., Denver. Arnott, John, superintendent, Colo¬ rado Fuel & Iron Co., Crested Butte. Babcock, C. W., Denver. Ball, Joseph, Walsenburg. Bayles, F. P., superintendent, Car¬ bon Coal' & Coke Co., Cokedale. Beach, Benjamin, superintendent, Colorado Fuel & Iron Co., Coal Creek. Beere, W. J., pit boss, Victor-Ameri¬can Fuel Co., Maitland. Berryman, Charles. H., secretary¬treasurer, Southern Superior Fuel . Co., Denver. Beuchat, Charles, Pryor. Bickerton, Richard, mine foreman, Colorado Fuel &. Iron Co., Tabasco. Bortman, John, miner, Colorado Fuel & Iron Co., Pictou. Bock, Henry, Box 1602, Denver. Bostwick, Fred H., Wellman-Seaver¬Morgan Co., Denver. Bowen, James V., Denver. Bowie, Alexander, general manager, Juanito Coal & Coke Co., Bowie. Bowie, Wallare D., Bowie. Breen, J P. Walsenburg. ,Brown, D. W., vice-president, Rocky Mountain Fuel Co., Denver. Bullock, W. H., salesman, Westing¬house Electric & Manufacturing Co., 1152 Gas & Electric Building, Denver

Jan 1, 1913

I have sketches of the radiators, and on this sketch up in here (indicating) we show the line from the fan-exhaust steam from the fan, and the trip spray at the mouth of the mine, which is usually near the tipple, the set of radiators on each side of the entry, exhaust steam exhausting in by the radiators, the small atomizers which I mentioned, and the man sprinkling at the hose. There are times, when at different times we have a man sprinkling during the day time, when he is out of the way, and during the night, sprinkling on the motor roads. I will leave that print up here and let you look at it and if you have any questions you wish answered, Mr. McAllister and myself will be glad to answer them. (Applause.) PRESIDENT PRYDE: . I am going to ask Mr. Hair to leave the sketch on the wall. From the back part of the hall, it is hard to see what is there. The figures are very important. I think one member of this association will be glad to know the cost of water, Friend Littlejohn. MR. LITTLEJOHN: I don't know as I want to ask any questions. The only thing I' would say about the cost there, it is very close to that cost that we tabulated for the Utah Fuel Company at the Utah mines here some time ago. We have not tabulated lately. It may be a little over that at the present time if you take the. labor costs and the material. costs. As I remember, some time ago we did get up some figures and it was, as near as I can remember, exactly two cents per, ton for the labor and material. We haven't got the radiators, etc., that the C. F. & I. have in their mines there, probably due to the fact that we have no shortage of water. We have plenty of that there, and our system is absolutely nothing more nor less than pipe lines, hose and nozzles and the man at the end of the nozzle. PRESIDENT PRYDE: I would like to ask Mr. Hair about the cost of the steam. MR. HAIR: That steam we use there in exhausting, of course, is from the fan, and we have a back pressure valve set right here (indicating), from three to four and sometimes five pounds, and the exhaust from the fan was a five or six inch exhaust, and our exhaust into the mine is nothing less than eight inches, and is practically low back pressure you might say, and all those large radiators, that I spoke of, are heated by live steam, and these probably take a little more coal, but as to just what that cost is I couldn't say. As far as the exhaust steam is concerned, you might as well use it in the mine as discharge it outside. MR. HARRINGTON: Mr. Hair, I would like to ask, is this installation on an intake haulage-main haulage course? MR. HAIR: Yes, sir. MR. HARRINGTON: In the winter time, when it is, say between five or ten degrees below zero, how far into that haulage road does the fogging go? MR. HAIR: Well, that goes in half a mile, sometimes in 3,000 feet. MR. HARRINGTON: Wouldn't that interfere pretty seriously with the motor? MR. HAIR: To some extent, but I wouldn't say seriously enough to interefere with the production of coal. We have one mine we are working in two and three-quarters miles. Our mines are all pretty deep, and we don't find it objectionable. I don't believe that it interferes in the production of coal. I don't believe it makes any more difference between a real cold day in winter time than it does in the summer time. MR. HARRINGTON: I was down at Dawson, and in their mines they have an installation very much like Mr. Hair describes, but we went in there one night and stayed all night, getting a certain amount of data, and the fog was intense for-a full half mile; so intense that you could hardly see your hand in front of your face-see your hand that far (indicating) dis-

Jan 1, 1924

PRESIDENT MOSES: I thank you, Mr. Emrick. Mr. Shubart would like to supplement your paper with another article. SECRETARY SHUBART: My paper really should not supplement Mr. Emrick's paper, because I secured some data from him, I knew Mr. Emrick had had a great deal of experience in shearing and I thought he could give you some useful data. (Here Mr. Shubart read the following:) "For the past two years, there has been considerable discussion among coal mining men concerning the advantages of a shearing cut in addition to the undercut, in mine work. We have had a number of requests for information on sheared coal. We were asked questions like these: What percentage increase in lump can be obtained from sheared coal? What has been the experience of mine men who have employed the shearing cut? Is the shearing cut a means of increasing the lump content? If so, is it increased to such an extent as to warrant the installation of shearing machines? Upon investigation it was found that no one could give us any definite information on the subject as no one had weighed separately the grades of coal produced from' the shearing cut. With a view of getting this information first-hand, the Goodman Manufacturing Company built up a shearing machine to be used in experimental work only. The officials of the Troy Coal Company were eager to share in the expense of obtaining this information, so that in May of this year we shipped to their mines our first type 319 shearing machine. The Troy Coal Company operates a mine at Troy, Illinois, in the No. 6 seam and produces about 275 tons daily. The coal seam averages five and one-half feet in thickness. Previous to the arrival of the shearing machine the coal was undercut six feet deep by a' Goodman Shortwall Machine. To break down the coal required two shots in the entries and three in the rooms. The percentage of lump measured over two-inch screens, averaged 58.2 per cent. The conditions of the mine were very favorable for obtaining accurate weights on the amount of lump and slack coal run over the shaker screens. The shearing machine easily cut the entire tonnage of the mine so that all coal dumped into the railroad cars had been produced from a shearing cut, in addition to an undercut. Accurate records were kept of the railroad weights and front this data the percentages of lump and slack were computed. During the month of June the percentage of lump produced over two-inch shaker screens was 69.9 per cent. This result demonstrated that the introduction of the shearing cut had increased the percentage of lump twenty per cent. The entries were driven ten feet wide and the rooms thirty feet wide The shearing cut was made near the center of the face in all places. A hole was drilled in each rib and the coal shot down with one-half the powder required when the places had been undercut only. The coal was broken down to the back of the cut so that very little pick work was necessary to load it out. The benefits derived from the shearing cut were as follows: 1. Increased percentage of lump, thus increasing the average price of coal per ton. 2. Preservation of a tender top due to the decreased amount of explosive used. 3. Facilitated handling of coal by the miner thus increasing the tonnage per man. 4. Eliminated coal yardage in entries and crosscuts of ten feet or less in width for the reason that the shearing cut provides a loose end from which to shoot the coal. This applies to the union fields only, as the non-union mines do not pay for coal yardage. Based on a price of $2.50 for lump coal and $1.25 for slack coal, the average price per ton was increased

Jan 1, 1926

By T. C. Harvey

Ladies and Gentlemen: At the request of Mr. J. M. Jennings, chairman of the General Committee on arrangements during the convention of the Rocky Mountain Coal Mining Institute here, I have endeavored to prepare a brief description of the Columbia Steel Corporation's tipple at Columbia, Utah, and its operations, but [ ] from the fact that you have already listened to, and have been interested I'm sure, in the description given by Mr. Jennings and Mr. Murphy, on tipple construction and operations, I am taking the liberty, with your permission, to embody in my paper a description of our haulage and ventilation systems at Columbia, which I hope will be, in a measure, also interesting to you. As many of you know, we are mining on a Multiple Panel System, which while comparatively new in Carbon County, is being used successfully in various mining districts of the United States. Mine The Columbia mine is situated about four miles south of Sunnyside, Utah, at an elevation of 6,760 feet at the portal or main entrance of mine. [ ] From this portal, the main air intake or solid rock tunnel, about 1,600 feet long, runs into the mountain in an easterly direction to an intersection of the coal vein on a grade of 0.5 of one per cent in favor of the loads. There this main entry divides and forms two main entries. These are run in parallel with 100-foot chain pillars between them and protected with 150-foot barrier pillars on each side, and run into the coal in a southerly direction on a 0.5 of one per cent grade in favor of the loads for a dis-

Jan 1, 1925

of our good friends and fellow members: Patrick J. Quealy J. C. Roberts Gilbert Morton Sidney W. Farnham who left the world better for their having lived in it

Jan 1, 1930

By Gilbert Davis

MR. DAVIS: When the Secretary asked me to continue our accident experience in safety work at Dawson to cover the year just closed, I rather felt that he was asking 'a good deal, for we had said about everything that we could last year. I am not going to say very much, but in line with his request I have merely brought the figures up to date. I want to say, to start, that 1934 was, rather disappointing. It was the poorest year since 1930, as you will notice (indicates on diagram). This first column represents the accidents per thousand shifts worked. We cannot assign any real valid reason for the increase. We think we worked just as hard, but we are rather inclined to lay it onto the times; in other words, to lay it to the unrest and the changing conditions that are existent not only in this country but probably all over the world. We had twelve lost time accidents last year. As I explained last year, a lost time accident with us is an accident wherein the injured man is not able to return to his regular work, the next day-the day following the injury. So this represents (indicating) the lost time accidents per thousand shifts worked. We had one fatality in the twelve accidents which is reflected in the severity rates, which are also based upon thousand shifts worked instead of per million hours. The reason we are on the thousand shifts worked is be¬cause the Copper Branches of the Phelps-Dodge Corporation are all kept that way, and we are on the same basis for easy comparison.

Jan 1, 1935

PRESIDENT PRYDE: Any discussion on Mr. Poster's paper? MR. J. BEVAN: I would like to ask the gentleman how fine the dust has to be to cause an explosion? MR. T. FOSTER: According to the Bureau of Mines, it is claimed coal passing through a 100 mesh screen would be considered fine enough. That is all I can learn from the different bulletins. MR. BEVAN: Will the coal dust be that fine; going back in the empty cars on the tipple in the mine? MR. FOSTER: Possibly a great deal of it would be. MR. BEVAN: Will the coal dust be that fine, going back, in the empty the coal dust going back in the cars on the tipple, and into the mine? MR. FOSTER: In some places, they are wetting the cars at the tipple, -in the Rock Springs District, we have as the trip goes out, they have a big pipe, and they souse the car, and wet the load, and in some places, near the timbers; that helps to a certain extent. That does not absolutely eliminate it all, but it helps considerable. MR. WM. LITTLEJOHN (Utah Fuel Company) : I think we have all listened very attentively to the paper that Mr. Foster has just read. He has brought up a subject rather close to my heart, for a long time. He mentions particularly, the Scofield disaster, which happened the first of May, 1900; two hundred men lost their lives in the explosion; and I think it is generally conceded that is about the first time it had ever been brought to the attention of coal miners or operators that such a thing was possible, namely, a purely coal dust explosion. The term "Scofield disaster" is rather a mistake, in a way; while the mine that exploded at the time is in the Scofield District all right, it is now known, and probably was known at that time, as the Winter Quarters Mine, one of the mines which belongs to the Utah Fuel Company at the present time, and did at that time. This mine

Jan 1, 1924

At 10 a. m., Tuesday, November 12, 1912, the following members of the committee appointed by "Coal Age" to organize a Coal-Mining Institute for the Rocky Mountain region, met in the State Capitol, at Denver, Colo. : E. H. Weitzel W. J. Murray T. H. O'Brien W. B. Williams James Dalrvmple F. W. Whitksiie A. C. Watts David Griffiths The following members of the committee were not present: Frank Manley Allan French H. C. Williams Frank Cameron J. E. Pettit D. W. Brown C. H. Gibbs E. H. Weitzel acted as chairman of the meeting. This committee drew up a form of Constitution and By-Laws, to be recommended to the general meeting to be held on the following day; and, with the exception of two alterations, this Constitution and By-Laws, formulated by the Organization Committee, were accepted as a whole by the general meeting. With the exception of a general discussion of affairs that might be brought out by means of such an institute, no further business was done at this meeting of the Organization Committee, and it was adjourned.

Jan 1, 1913

Saturday, June 28 A pre-convention activity kicking off the 93rd RMCMI meeting was a Saturday evening June 28 reception for all Mine Rescue participants, their convention registered spouses, professional evaluators and RMCMI Board of Directors. This was at Buddy's Run in the Sheraton Steamboat Resort, Colorado. An estimated 100 persons enjoyed the buffet: fresh vegetable erudite with ranch dressing, fresh fruit and cheese displays and silver dollar rolls filled with ham or turkey. Blue golf shirts and red caps and convention packets were distributed to each Mine Rescue team member. Evaluators received red shirts and blue caps during the reception. Meeters and greeters from the Reception Committee wore red RMCMI arm bands and were stationed at strategic hotel spots, answered attendee's questions and gave directions to the registration area. Convention packets were first distributed Saturday afternoon by Julie Cummings and Lorraine McDonald. Sunday, June 29 A 7:30 a.m. shotgun scramble kicked off the golf tourney at the Sheraton course for 145 golfers. Yes, 145! as Lois Egan, President Tom's wife, completed a five-some with Tom and their three sons. A continental breakfast preceded the tourney. Another 65 golfers began play at 1:00 p.m. making this a record number of 210 golfers! Julie Cummings and Loren Linville sold $2,620 worth of $10 mulligans to the golfers with proceeds to the scholarship program. [ ] Both golf tourneys were co-chaired by Dave Mallak and Gordon Merriam who distributed prizes at 4:30 p.m. Monday. Prizes were donated by Amax Coal Sales West, Inc.; Austin Powder Co.; BHP Minerals-Navajo Mine; Bucyrus International, Inc.; Commercial Testing & Engineering Co.; Empire Machinery Co.; Ingersoll Rand; The Jeannot Group, Komatsu Mining Systems; Long-Airdox Co.; Marston Environmental Inc.; MEGA Corp.; The P&M Coal Mining Co.; Scandura, Inc. and TerraMatrix. [ ] RMCMI registration was an all day venture headed by chair Julie Cummings and assisted by Pat Johnson. [ ] Nearly 40 persons met for a Chef Demonstration and wine tasting at the Sheraton at 11:00 a.m. Executive Chef Jacques Wilson prepared broiled achiote shrimp with cantaloupe, grilled duck stuffed blue corn pancakes with herb grained bread and fresh fruit meringues. Wilson shared his recipes with the group and appropriate wines were served with each course, all sampled by the attendees. The chef arranged an impromptu showing of the main kitchen following the demo. [ ]

Jan 1, 1997

Jan 1, 1955

By O. C. Irwin

For several years the C. F. & I. Co. men have been working on a fan signal and many different schemes have been tried. I will describe a few of them. A make-and-break attachment was placed on the fan shaft which caused a light to flicker. A hinged door was placed on air course and counter balanced so that it would have a slight travel when the air pressure was reduced an appreciable amount. This motion was used to open the power circuit, blow a whistle, or ring a bell. Series transformers were placed in motor leads of fan drive motor and the variation in amount of power to motor was used to control the fan signal through a magnet or relay. A governor was placed on the fan shaft which opened a signal circuit when speed of fan was reduced. We tried to produce a machine actuated by the volume of air, (that is on the principle of the anemometer) but had to discard this due to its being too delicate. None of the above schemes seemed to fill the conditions which the State and our Mine Inspector wanted covered. They gave us the following demands for a signal: 1. Must open mine circuit and sound alarm when air pressure was reduced below a certain amount. 2. Must be fool proof. 3. Must work on any kind of fan drive (steam or motor). 4. Must be safe to ' install- in any mine or fan house. 5. Must not depend upon mechanical device which could become inactive due to friction or other causes. 6. Must be as simple and easy to adjust as possible.

Jan 1, 1925

PRESIDENT LITTLEJOHN: I have every reason to know Mr. Pryde was carrying out some experiment a while ago in some of his mines. He and I had a little correspondence on the question, and I think he may have a word or two to say about it. He has not been on his feet today at all. I will ask Mr. Pryde to tell us what he has to say. MR. PRYDE: I have not very much to say about shooting coal with permissible powder as far as slack is concerned because we are not in the commercial business. All of our coal goes to the railroad and a very large part of it is crushed for use in the stokers of the locomotives. We are on a 100 per cent permissible powder basis and as far as I am able to see, I do not believe that the percentage of slack is increasing with its use. We find it hard to convince our commercial neighbors of this fact because they are naturally very much against increasing their percentage of slack on ac- count of the low price received for this grade of coal. I, personally, believe that where a change is made from black powder to permissible powder the percentage of slack will be increased for a time because the miners have been accustomed to using black powder and they are rather suspicious about going to the permissible powder and I do not believe that we can blame them very much. So the tendency with them is to use too much powder. We have gradually overcome this, although, as I said before, we have not kept close track of the production of slack. However, we try to get as large an amount of lump coal as possible. Broadly speaking, I can say from observation that in my opinion there is very little difference in the percentage of slack with the use of the permissible powder that we have today than there was with the use of black powder. I also get this information from our mine superintendents. Mr. Peterson and the other explosive men have been very helpful to us in the use of permissible powder and I confess I have to take everything back that I said several years ago. At that time I was against permissible powder, particularly on account of the cost, but, with the newer permissible powder, we have gotten the cost down very well. I know today that the cost of permissible powder in the coal mines of the Union Pacific Coal Company is less than when we were using black powder. I know this because of the fact that we kept a record of the number of tons we got with black powder, and the number of tons we get with permissible powder compares very favorably in cost. I know this, too, because of the fact that our employes, except in the first few weeks of using permissible powder, have made no demand upon us for any in- crease ill pay to offset any added cost that might accrue in the use of permissible powder and the fact that they have asked for no increase is very conclusive proof to me that it is not

Jan 1, 1925

By D. C. McKeehan

The use of electric power was introduced in this field in the year 1892. The initial installation being an engine-driven generator and one nine-ton haulage locomotive using 500-volts direct current. Reference to this locomotive appears in the issue of COAL AGE for February 24, 1921. For a large coal field, the conversion to electricity has been very complete, there being no compressed air machines in service and but one steam driven hoist, that at No. 1o mine and located within fifty feet of the present power plant boiler room. Two eight-ton haulage locomotives, installed in 1896 and still in use, justifies the service and the equipment. These mines used the pioneer types of electric cutting and drilling machines, the story of which is, no doubt, familiar to you. The extensive use of electric power began in 1900, when there was installed four 400 k.w., 500-volt direct current engine-driven generators. These were cross-compound machines and operated non-condensing. By 1910 the mines had developed main haulage entries of several miles in length and a working territory of about six square miles in area. The necessity of supplying adequate power at the working face required a local power supply from motor-generator sets in various parts of the mine to supplement the power furnished by the engine-driven generators. The power to these motor-generator sets was supplied by a 300 k.w. high pressure non-condensing turbo-generator delivering 2300 volts, 60 cycle, three-phase current. This marks the beginning of the use of alternating current for mining purposes. In 1913 new mines were being developed at Reliance, seven miles distant, and the plant was enlarged to accommodate a 750 k.w. low pressure, condensing turbine, utilizing the exhaust steam from the cross-compound engines and the 300 k.w. turbine. Transformers were installed for supplying Reliance with power at 13,200 volts. In the course of time the old engines began to dismantle themselves by throwing various pieces, such as cylinder heads, about the building, damaging walls and switchboards, and created a general feeling of unrest among those who had to do with power production. The limitations of the old engines that had given admirable service for ten years were recognized. The source of exhaust steam became questionable and in 1915, a 1000 k.w. high pressure condensing turbine was installed in order that a more general use could be made of motor-generator sets for the direct current supply. The plant at that time containing a 1000 k.w., a 750 k.w., and a 300 k.w., in alternating current generators, supplemented

Jan 1, 1921

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