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The opening session of the Forty-seventh Meeting of the Rocky Mountain Coal Mining Institute was called to order at 10:00 o'clock a.m., Thursday, June 7, 1951, in the junior Ballroom of the Hotel Utah, Salt Lake City, Utah, with President Arthur B. Foulger presiding. PRESIDENT FOULGER: We are a little bit late getting started, gentlemen. We have a few more members out there to register and we will wait just a few minutes until they are finished and then we will begin. The Honorable Earl J. Glade won't be here until 2:00 o'clock this afternoon. I understand lie was unavoidably detained so we are going to go down this program pretty rapidly when we get started, but we want to wait until those gentlemen still unregistered come in. Gentlemen, we will try and start now. Mr. Whiteside suggests that the minutes for last year probably should be read. However, they were published in the proceedings for last year, so I presume it will be just as well to dispense with the minutes and get going here before we lose too much time.

Jan 1, 1951

Winter Meeting Cosmopolitan Hotel DENVER, COLORADO February 27,28 and 29,1928 Business Meeting 10:OO a. m., February 27th Banquet 6:30 p. m., February 27th Dancing 9 :30 to 1 :00 a. m., February 27th Theatre Party, February 28th Special efforts will be made to care for lady guests

Jan 1, 1927

By R. S. Morton

MR. CHAIRMAN AND GENTLEMEN: To be invited to address the members of The Rocky Mountain Coal Mining Institute on a particular subject is an honor I sincerely appreciate. The subject of this paper is, ?The Advantages of Having Such Men as the Fireboss Under State, Rather Than Corporation Jurisdiction." On the fireboss, primarily, depends the safety of the mine. When all the rest of the mine workers are still comfortably sleeping in the wee small hours of the morning the fireboss steals noiselessly away, from his bed to take up his daily task, a tour of inspection. He enters the mine, he inspects alone they workings that will be filled with men whose safety is in his keeping. Loyal to his fellow men and responsibilities of his position; he seeks for danger in every place, on every road and travelingway; going over caves, through dangerous places where none of the others are expected or allowed to go alone. How many of us give a thought to these dangers and the faithful work that this guardian performs for our safety. After the fireboss has made this round of inspection, he reports all the dangerous places to the foreman and enters them in the book; he is supposed to have performed his duties; he has no authority to enforce his recommendations. He has found a number of rooms that have not been timebered as they should be for the safety of the digger; he has told the diggers to they timber, up better for their own safety; he has kicked to the foreman about these same places. These conditions. continue until there is an accident. The fireboss reports, broken crossbars or bad roof on a roadway or some other danger to the foreman, but the foreman does not have it fixed, making, excuses, as he cannot put any one on that work today; or that it will stand until some idle day, and that is the way things go until the fireboss gets so he wonders what good he really is, is it any wonder it is hard to get good men to take this position of fireboss? The remainder of the shift the fireboss is used as a general roust-about, having to do such, work as building stoppings, help the timberman or track layers, pull rails out of danger in pillars, a trapper is off and he is told to trap that day, when the mine is idle he is laid off to cut expenses. That is the way the fireboss is treated. The fireboss is not merely a merely a necessity to be lightly regarded but a factor whose authority should be unquestioned. The fireboss has made his district and knows just what conditions the workings are in, and sees lots of dangers that the foreman does not. In the morn-

Jan 1, 1921

By Fredrick D. Palmer

U.S. ENERGY: PUTTING PEOPLE FIRST Assessing Goals, Needs and Resources ?Decision-makers must balance the needs of average Americans with the need for: ?A strong economy ?A clean environment ?A secure nation ?Events of recent years ?terrorist acts, multiple energy crises and a global focus on sustainable development ?magnify the need to balance these principles ?Coal ?domestic, abundant, affordable and increasingly clean ?meets these needs like no other energy source

Jan 1, 2003

By David Scrymgeour

All low cost coal has been mined. Engineers are searching for a safe and effective way to mine coal seams' deep within the earth. The most modern of these is the RL, an acronym for Robotic Labor. Mining robots are programmed to do specific jobs but can think on their own during an emergency. MR's, or mining robots, usually have a same basic shape. A torso is mounted on treads. Designers chose treads because it gives the robot a great deal of mobility. The torso has two arms. One arm is equipped with a human hand. The other has a human-like hand. Mining is done underground. A small robot goes around punching holes in the coal. A small charge is inserted in the hole. The MR ignites the charge with his laser. It explodes after three minutes. The MR returns to the station where his battery is recharged. Mobile cement barricades are moved between the blasting area and other working MR's. After the charge explodes the barricades are moved to another area. The MR returns and cuts the coal chunks into pieces. Another robot comes and loads the coal and carries it to the loading bin. From there it is taken to the surface where it is weighed and shipped. The whole process was done by robots. Humans just supervise but help in an emergency or malfunction.

Jan 1, 1987

MR. ENZI: hank you very much. I'm sure there?s a lot of you out there just realizing that Rock Springs and Gillette is not one city. I'm sure there's a lot of you wondering why a person from a town who has the image in the national media that the town of Gillette has is talking to you about image. I had a person this morning ask me if Gillette wasn't the end of the world. The only response I can give is "no, but you can see it from there." We have been researched a lot and, I realize, we've been very lucky because I've observed that researchers cause cancer in rats. In fact a wonder drug is one that has no effect on mice. In fact I've been thinking of posting a sign in my office that would read "due to the large number of interviews by journalists who already have their articles written, we would most respectfully request that anyone wishing to insult the city of Gillette, please limit themselves to 3,000 words or 15 insults, whichever is shorter." I don't know if any of you saw the article in Playboy about three months ago on the city of Gillette. What you probably don't realize about that article is that that was an attempt by Playboy magazine to see if they couldn't change their image to a national municipal magazine. I think it's important to know Gillette is the frontier city, a pioneer city, it's a shopping center for northeast Wyoming and most importantly, we're the energy capital of the nation. We're on the threshold of the Powder River Basin and we will be the nation's energy solution. Besides coal, we're, already the heart of the state's leading oil producing area and we have vast uranium resources. But I, want to tell you the biggest resource that we have is, the people who have come to live in Gillette. You will find Gillette a busy, young, pulsating community. We're experiencing the excitement of growth. We're welcoming a higher percentage of newcomers than any other town in the nation. Yes, growth to us is exciting. Where else can you get ten years of experience in two years? We realize you can't maintain the status quo. Growth can be painful but not as painful as the alternative, recession and depression. For a little bit of background, we are now at 16,000 people and we have another 4,000 people who live on the outside but look like they live on the inside. The Census Bureau says that we have, 11,225 people but we have that many people in a traffic jam on the Douglas Highway in one day. I?ll , tell you about a few things happening in Gillette. I think it's very important to emphasize that I didn't , do these things; it's the youth and the energy of the community that has done these things. Right now the city of Gillette has 32 major projects underway. We have water for 50,000 people and we're seeking more water. The city in 1975 was 1 .8 square miles. Last year alone we annexed I square mile. We build 10 miles of paved streets a year. For the last 8 years we've doubled our parks' budget. I

Jan 1, 1982

By Michael A. Berdine

Twentymile Coal Company?s first longwall face in the late 1980?s was oriented approximately 45 degrees to the major coal cleats and 45 degrees to the primary horizontal stresses. This combination of stress and coal cleating resulted in frequent violent bursts of coal along the longwall face. The bursts created particles of sufficient size and force with the potential of causing injury to employees and occasional damage to shield components. Partial web cutting was subsequently developed in an attempt to relieve the stress on the coal face and required the shearing machine to travel to the tailgate and back for a full 36 inch web. The partial web cutting pattern is focused on first cutting the lower 90% of the seam to relieve the stress as the shearer travels from the headgate to the tailgate. The web depth during the headgate to tailgate pass is typically in the range of 70% to 80% and varies with conditions to maximize production rates. The top and bottom of the seam in the remaining 20 to 30% of the web are then cut out to allow the shields and face conveyor to advance. 100% of the web is cut at each gate end for a distance of approximately 19 shields. This paper addresses some general mine geology and the procedures and benefits of partial web cutting with respect to safety, production and maintenance on a high production longwall face.

Jan 1, 2004

By Geo. A. Brown

This paper was written from conditions existing in the Cumberland Mines of The Union Pacific Coal Co., with my impressions and cause of same. These mines are located on a branch line of the 0. S. L. R. R., about sixteen miles south of Kemmerer, Wyoming. The mines are the property of The Union Pacific Coal Company with headquarters at Rock Springs, Wyo. There are two mines, No. 1 and No. 2, located about two miles apart in a seam of coal averaging about 16 feet thick which is split with a parting of rock from 4 feet to G feet from the bottom, averaging from 4 inches to 5 feet thick, mostly of soft fire clay, with an average pitch of 21 degrees to the west. The lower coal below the fire clay band being of a soft nature, much softer than the coal above it. The cover or roof next to the coal is of a massive sandstone formation from 4 feet to 60 feet thick while the floor of the seam is of a soft fire clay as far down as has been prospected. These mines are also of a dry and dusty nature, they generate lots of fire damp and are subject to fires from numerous causes. These mines were opened up in 1900 with five openings each, Main Slope, North and South Manways and North and South Aircourses driven parallel directly on the pitch of the seam which is fairly regular, entries being turned North and South at right angles off the slope about 300 feet apart. The entries were driven double 10 feet wide with chain pillars from 20 feet to 30 feet thick. The main entries are used for haulage and main intake, back entries for return aircourses. Rooms are turned on 50-foot centers and 20 feet wide, directly on the pitch Galvanized sheet iron chutes are used in the rooms. The slopes were driven down in No. 1 mine about 4,000 feet, in No. 2 mine about 5,000 feet where the cover would be about 1,400 feet in No. 1 mine and about 1,700 feet in No. 2 mine approximately. When a point about 2,000 feet on the slope had been reached with cover, 600 or 700 feet squeezing became noticeable on the entries and room pillars with slight bumps which extended clear to the upper entries of the mines and continued to get worse as the mines got deeper and with more cover as no pillars had been removed at this time. It should be stated here that faulty ground was found on the south side of No. 2 mine and on the north side of No. 1 mine, in some places looking like a fault of a down throw, some places like a want and other places like an erosion. The latter theory seems to be correct from prospecting and drilling. The mining of entries and rooms became more difficult with more squeeze and bumps of increased pressure which closed entries and aircourses and finally caused the lower workings of the mine to be abandoned. It was then decided to open up the entries from the 6th up, or approximately half way up the slope. The opening of these entries was started with the intention of extracting pillar coal but considerable danger was met with for the entries .were squeezed tight and when they were disturbed, bumps and squeeze conditions had to be contended with, also gas and fires due to the continued grind on the pillars due to overhead pressure bringing on friction which caused innumerable fires to start in the bottom coal. Bumps being so extensive at times as to close up aircourses for 500 or 600 feet, also discharge timber, coal and rock from the rib of slope and entries for hundreds of feet, dislodging tracks and throwing mine cars around just as if an explosion had taken place, filling places with gas and throwing dust into the atmosphere so that you could cut it with a knife. It became necessary to discontinue the use of black powder and naked lights entirely as a safety precaution. Permissible Powder Monobel No. 5 and Wico Electric Safety Lamps were installed. All coal was shot off the solid whenever it was necessary to shoot. ' In opening up these entries it was found that practically all of the weight was centered on room pillars up to the first crosscut chain pillars and barrier pillars between top of rooms of entry below and the one above which averaged 30 feet thick and in all practically 120 feet of ground. The rooms were mostly open from the first crosscut up to the face which showed that the points mentioned had taken the weight. It was found impossible in some of these entries to drive double entries again as the bumps and squeeze made it impossible to maintain them. This made ventilation quite a problem, small booster fans and flexoid tubing being used for ventilation until one entry could be connected with the one above which has solved most of our ventilation problems so far.

Jan 1, 1924

PRESIDENT LITTLEJOHN: Before we open the discussion on the Utah mining laws, I want to bring out what I consider a slight misunderstanding on some of the things that I said this forenoon relative to our comparison of accidents. I did not mean to infer that we, as mine officials, are satisfied we have done the best we can to eliminate the accidents, when I was talking about a four-to- one comparison. I do not want any- one to get the idea in their heads that I do not think we are doing all we can. There is not any of us who can state that, even if we better these figures. It is the general understanding that these figures are based upon ratios per thousand man shifts and not upon the tonnage basis that we use. If it were based upon a tonnage basis, I think the figures would be pretty nearly reversed, for we are producing from two to four tons more per man than they do in Great Britain. The discussion will now be continued as I said this morning. There is a gentleman in the audience here that is as guilty of making these laws as I was, and I am quite sure when speaking he will confine himself to the subject of Utah Mining Laws and the prospective results. Before Mr. Monay starts with his paper, I want it understood that this discussion must be finished by 2:30 for the reason that we have still quite a lot of business before us this afternoon.

Jan 1, 1925

By Paul Schmechel

This time of year, our lawn is host to goodly numbers of birds - robins, English sparrows, finches of various flavors and some whose names I don't know. We lure them with a feeder in our backyard and I'm sure Patti and I spend several minutes a day watching them through a picture window that overlooks their coming and going. And, while the picture window supplies us with a constantly changing view, it does not treat our winged friends nearly so kindly. You see, at certain times of the day, reflections on our window feed back to our birds a mirror image of the backyard. Lifting off from the bird feeder, they see before them what is behind them. And, not infrequently they fly straight into the window. They stop abruptly, of course. It has to be quite a shock to discover that what is behind you is not the same as what is in front. At this point, I might be tempted to say something about bird brains - except for the fact that we humans also are prone to deceptive images thrown up by the past. Today, I think we hear a great many voices painting past images as they look to the future. We hear that the price of oil soon will rise to its former elevated position; the price of copper will bounce back; a hungry world soon will escalate the demand for food and our agricultural industry will be back in the black. In fact, we can hear hope from many voices telling us that our major resource-rich, basic industries are poised to fly up. I can hope that the voices are right, but I keep thinking that those expressions come from people seeing false images. Most certainly, it is more comfortable to see the past, rather than acknowledge that the world economy is being restructured and that the restructuring is affecting the Rocky Mountain states profoundly and negatively. The worst mistake we could make may be to place too much credence in the images from our past. We can be lulled into a dangerous complacency. What we need is a tighter belt and the will to do some serious bootstrapping. Before proceeding, I would make two points: First, it is not my intent to be a prophet of doom. But I do think we need some healthy doses of realism, if we are to avoid the shock of flying into a false future. Second, by now you have detected that I have choosen to diversify the assignment you handed me on utility diversification. As I proceed, you soon will see that the roots of diversification for many utilities lie in the subject that we ponder now. We could begin in many places, but let's start with energy. It is pervasive in our businesses and industries. We all use it. And, despite conventional economic wisdom, we are using less of it. The price is down, but we have not reverted to our profligate ways. That is true whether you look at the industrial customer or the residential consumer. As a nation and as a people, we have learned to do more work with less energy. A few statistics illustrated the point. If we use 1973 as the base year, energy use in the United States has declined almost I percent. If we examine the year of peak energy use, 1979, the decline approaches 7 percent. Let's look at it another way. In 1973, for every dollar of gross national product, the United States consumed 27,100 Btu of energy. Last year, 1985, the comparable figure was 20,700 Btu - a decline of 24 percent. So, not only are we using less energy, but we are using it more efficiently. Even though the price of energy has declined, we are unlikely to use substand with natural gas and petroleum consumption. Use of natural gas has dropped almost 21 percent since 1973. Petroleum consumption has declined 1 I percent since 1973 and almost 19 percent since 1978, when the U.S. used a record quantity of petroleum. We also know there's been no appreciable change in amounts of oil and gas used since 1981. We weathered both a sharp recession and a healthy recovery without altering the amount of those fuels used. That the use of oil and gas dropped sharply, while the total use of energy merely slumped a bit is easy to explain. The use of coal, nuclear power and hydroelectricity from 1973 through 1985 increased almost 48 percent. Some people will tell you that the large decrease in the price of oil and gas will result in increased demand that will displace coal, nuclear and hydropower. In turn, demand will force the price of oil and gas upward. I doubt it. From the poking around I've done on the subject, I suspect there may be some short-term displacements, but they will be, for the most part, cancelled out by declining use among existing customers. For instance, we all know what has happened in the automotive sector. In 1973, the average U.S. automobile made 13.1 miles to the U.S. gallon of gasoline. In 1984, the most recent available statistic, the average auto made 16.94 miles to the gallon. That's a 19 percent improvement. Because annual miles driven per automobile are essentially unchanged over the period and the number of cars on the road is not increasing, we are witnessing a drop in this segment of the petroleum market. That trend will continue. Now, let's look at energy consumption patterns still another way. Between 1973 and 1985, consumption in the residential and commercial sectors of our economy increased total energy use by 11.2

Jan 1, 1986

PRESIDENT WETZEL: The meeting will come to order. We are pleased to see a few of the more hardy survived last night's-ordeal and are present this morning. The Secretary has some correspondence which he will read. SECRETARY WHITESIDE: Gentlemen, I have a couple of telegrams and a letter which I would like to read to you at this time. First, a telegram addressed to Mr. Wetzel: "Regret greatly necessity canceling my plans to be present at meeting. Appreciate your conveying my best wishes to members for successful and profitable session.

Jan 1, 1942

Briefly, the machine consists of a steel frame mounted on roller bearing wheels and axles, an electric motor, a fully enclosed speed reduction gear unit, a specially designed centrifugal pump driven through a friction clutch and silent chain, a mixture tank and agitators, and all necessary operating and control mechanism. The wheels are mounted on solid roller bearings made of special roller bearing steel, and are cast with deep chilled threads. The axles are of high carbon axle steel. A General Electric Company motor, of special design to exclude dirt and moisture, is used. It has an unusual overload capacity and a maximum torque at starting speed. Special arrangement can be also made for storage battery operation. The motor drives from one end, through a flexible coupling, to the speed reduction unit, and from the opposite end, through a similar coupling, to the pump clutch. The design of the flexible couplings is such that the drive is reversible. The speed reduction gears are enclosed in an oil and dust proof housing. All spur gears, as well as the main drive clutch, are made of steel forgings, with accurately cut teeth. An aluminum bronze worm wheel and special heat treated alloy steel worm provide the speed reduction for the traction drive. The worm shaft is mounted on Hyatt roller bearings and the thrust is taken in each direction by ball thrust bearings. The main drive shafts are of special alloy steel and operate in Hyatt roller bearings. The slow speed shafts run in extra large bronze bushings. Ample and constant lubrication is provided by splash from the gears running in oil. The Mudite pump is of special de- sign. A renewable wearing plate protects the pump casing from the natural wear of the mixture. The open runner is mounted on an extra large shaft which runs in a Hyatt roller bearing on the pump end and in Timken roller bearings on the outboard end. A special cage prevents water and grit from reaching the pump bearing. All thrust from the runner is taken on the Tim- ken bearings and these bearings also provide for the accurate and easy adjustment of the runner. The pump is driven by a silent chain, which operates on cut steel sprockets, from a friction clutch. The clutch is designed to secure long wearing qualities with minimum attention and its adjustment is easily effected. It is mounted on Hyatt roller bearings and the clutch drive shaft also runs in the same type of bearings. The pump discharges through a nozzle, which is adjustable, and controlled by the operator. The mixture tank is of approximately 650 gallons capacity. It is provided with a mixing well constructed of perforated plate screen to prevent large hard particles from getting into the valve or pump. The tank is filled through an opening in the top directly into the mixing well. On a shaft running longitudinally through the tank are arms so arranged that the mixture is thoroughly mixed and kept in continuous circulation from end to end. This shaft is driven from the speed reduction unit by a steel roller chain operating on cut sprockets. The traction drive is taken from the worm wheel shaft through steel roller chains of extra large size that run on cut steel split sprockets on both axles. An idler sprocket provides for easy chain adjustment. The axles are mounted in solid roller bearings in fully-enclosed dust proof housings, which support the frame through coil springs. These springs eliminate twisting strains on the frame on account of track irregularities and also relieve the working mechanism from road shocks. The speed reduction from the motor to the wheels is such that it gives an operating speed of approximately ninety to one hundred thirty feet per minute. The brakes are of the conventional shoe type and engage the wheels on both axles. They are operated by a hand wheel conveniently located and

Jan 1, 1925

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

MR. MARGOLF: Thank you very, very much Harris. There's sure a lot there to think about in terms, of our image, particularly. I think we should keep' in mind what Harris said about our history not being monolithic. Therefore our image can only be that, which is reflecting the weakest link in our industry and I think that's a burden on all of us. Perhaps to do some policing amongst ourselves to try to improve whatever might be our weakest link and thereby elevate our entire industry. Our third speaker this afternoon is another good friend of mine of long standing and I am very pleased to be able to introduce to the Rocky Mountain Coal Mining Institute Bob Golten. Bob is a graduate of the University of Michigan with a degree in Economics and Harvard Law School. His professional experience encompasses private practice in Chicago where he was born and in the federal government as a public defender in Washington, D.C. and in the Department of Justice as a tax , attorney. Some of us have come to know Bob more in his present role as the senior counsel for the I National Wildlife Federation. He's also Adjoint Professor of Law and Director of the National Wildlife Federation Resource Clinic, University of Colorado. Boulder campus. In addition, Bob has served with the Rocky Mountain Center on Environment as one of its directors for a number of years. He's very active in a number of areas that are not only civic but he does reflect what I would present by way of introduction as a perspective

Jan 1, 1982

By T. H. Butler

February 22nd, 1926. Mr. Benedict Shubart, 521 Boston Building, Denver, Colorado. Dear Mr. Shubart: At your request, am submitting to you several suggestions for the amendment of our safety code which you felt should be kept up to date. As before, am advising you that these suggestions do not have the approval of the entire Safety Committee, but rather are the individual opinions of several members who have expressed their wishes in the form of letters to me. I am particularly indebted to Mr. Dan Harrington and Mr. Wm. Littlejohn for their assistance. Would recommend the following amendment a to the various sections. Section 1. Wherever possible trolley wires should be securely hung to roof or timbers at a distance of not less than five feet and not more than six and one-half feet above rail and six inches to one side. Spacing of hangers should be from 20 to 25 feet apart. Section 2. 500 volts D. C. should not be allowed in any installations. Trolley wires should not carry a voltage of more than 250 D. C. Pumps, mining machines and other small machinery units where A. C. power is used should not carry a voltage of more than 220. Large units, such as pumps, motor genera- tor set and hoists, may use a voltage of 2,200. When power cables to operate same are of armored construction, cables should be securely buried at all crossings. Section 4. Where power lines pass through door frames or stoppings they should be properly insulated with porcelain or rubber tubing. Whenever men get on or off man-trips in vicinity of trolley wires same

Jan 1, 1926

MR. DICKINSON: There is an increase of dust in machine loading, especially with the McKinlay loading and cutting machine which was extremely dusty. MR. FORRESTER: Declared more dust must be expected because when loading by machinery, the coal is shot harder in order to make it easier for the machine to pick it up. He believes however, that there was less hazard because of the closer supervision possible by reason of the concentration of operation. MR. McAULIFFE: Machine loading more dusty than hand loading. D. HARRINGTON: The hazard is greatly increased by modern methods of loading. Not only do the methods increase the quantity of dust, but they also increase the rapidity of mining and the increased quantity of coal broken down causes large quantities of gas to be released. The number of motors on loading machines and conveyors add to the hazard. No more dangerous places can be found for such motors than at the working face where there is excessive quantities of pure coal dust and where there is more gas than along any other point. Regarding Mr. Herres remarks that the machine loading was safer on account of the concentration and possibility of close supervision, Mr. Harrington said he believed concentration likely to prove a source of danger rather than its preventive. At Dolomite, Alabama, a number of men had assembled, and as a result what was a relatively small explosion killed a large number of men. Concentration is not without its dangers to mine operations. MR. McAULIFFE: These arguments do not appeal to me. Few places are better sprinkled than the working places in a machine loading mine. There is. more effective supervision, and there can be more ventilation. I believe machine loading will increase safety by that very concentration that Mr. Harrington deplores.

Jan 1, 1925

MR. C. M. GODDARD: Mr. Poli invented this little safety switch box. This junction box he has does improve the appearance mentioned in the underground junction boxes used in the foreign countries, where this thing is compulsory. There was some arrangement whereby the attachment could not be made with the switch in. The switch has got to be out of place before they can put the terminals into this box, which avoids all possibilities of short-circuits, except where protected on the inside of this box. In mines that are not gaseous, this is not so essential, but he has invented a very small junction box which probably. could be built for six or eight or ten dollars; if those things are necessary, for the handling of mining machines and their apparatus, takes current off the transmission line, and he has something that would meet that requirement, and I think when it is looked into it will meet the approval of the Bureau of Mines. He had this little box yesterday, and some of the members had looked it over and think, if they will look more favorably into it, they will find something to their advantage. PRESIDENT PRYDE: I think it is a good idea to bring in safety appliances and devices at this meeting. There were two more devices brought in here this morning; one a safety powder flask, and the other a carbide can. We have talked a great deal about permissible powder. It is going to take a little time to change over, and we would have to use the black powder cans. I will leave them in the window, if you care to investigate them.

Jan 1, 1924

PRESIDENT BOTTOMLEY: Gentlemen, the next order of business, if you wish to discuss it is Mechanical Loading. We still have a little time left that could be devoted to that subject, and the meeting will be open now for that purpose. Where is Mr. Edge- worth? J. E. EDGEWORTH (Foreman, Union Pacific Coal Company, Rock Springs, Wyoming): Here. PRESIDENT BOTTOMLEY: Yon start the ball rolling. Tell us what you are doing in the Rock Springs District, on the mechanical loading. SECRETARY SHURART Mr. Edgeworth is the man at the face handling the coal. He never sees the light of day these late winter mornings.

Jan 1, 1927

PRESIDENT LITTLEJOHN: The paper of Mr. Emrick will now be open for discussion for about twenty minutes. The meeting is now open for discussion. MR. EMRICK: There is some question that may have occurred to you at different times, that is how are you going to tell when the bits are properly made? A fairly good rule to go by is when the used bits come out of the mine, if half of them are bent and half of them are broken, the average is pretty good MR. GEO. B. PRYDE (Union Pacific Coal Company): I would like to ask Mr. Emrick if he has any figures as to the saving of Dower with the different styles of its. MR. EMRICK: I suppose you mean chisel point bits and pick point bits? MR. PRYDE: Yes. MR. EMRICK: So far as I have been able to learn, the only reason why chisel point bits are used is to prevent coring that might be done by the cutter chain. The pick point bit, of course, is the proper thing to use. It can be used when the position of the cutter links in the cutter chain is right. I do not know of any figures which give power consumption ratings on the use of pick point and chisel point bits, but there are tests and ratings, etc., which have been taken- which have been tested as against different bits, which have been given proper clearances against bits not having been given proper clearances, and they will run,-in their saving in power, they will run 20 to 25 per cent. MR. A. C. WATTS (Chief Engineer, Utah Fuel Company) : I would like to ask Mr. Emrick if he has any record showing the saving in power on using the alloy steel chisel bits. I know that several experiments have been made; I do not recall the figures now, but we had a very decided saving in power. MR. EMRICK: I haven't any of the records. Do you think that is because of the steel that has been used? MR. WATTS: Well, they were all sharpened by the same man and used in the same machine, and at the same shop. I do not know the composition. It is "Red Star" Vanadium that I had in mind. MR. EMRICK: I have not seen any records. Some companies are using the tool steel bits because they stand up a little bit better. MR. BENEDICT SHUBART (Secretary) : I was going to ask Mr. Emrick about that question. There is one company that does not recommend tempering the bits. They recommend using not exactly self-hardening steel, but one that is bard enough without quenching-they use 80-90-point car- bon but about a 70-point manganese, not exactly self-hardening steel, but they do not temper this at all. Will Mr. Emrick state if a steel of that kind could be worked in the bit sharpening machine that his company makes, as it

Jan 1, 1925

By Joseph Harrington

It is sufficiently correct to say that domestic solid fuel is universally hand fired and it is almost as correct to state that a very large proportion of hand-fired domestic fires are extremely inefficient and smoky. This is particularly true with raw bituminous coal for the fuel. The smokeless and efficient firing of domestic coal affords one of the most difficult problems confronting the combustion engineer. This is due to the universally constricted combustion space in the domestic furnace, the complete ignorance regarding the laws of combustion on the part of the average person, and the fact that the laws of efficient combustion are almost completely nullified under these conditions. It is well to familiarize ones self with these laws. These are: 1. The gradual introduction of the fuel to the furnace. 2. The admission and mixing of the right quantity of air with the coal gases. 3. A temperature high enough to permit complete combustion, and 4. A furnace space of volume sufficient to permit of the combustion gases and the oxygen getting together within the confines of the furnace. Even a casual inspection of the domestic heater will show that none of these essential things are present in proper degree, and this is the reason why the problem of domestic firing presents such difficulties. I have analyzed these conditions in a paper published by the Black Diamond, and which has already had wide distribution, so that I will not repeat the rather lengthy discussion in this paper. A survey of the entire field indicates very clearly that a reversal of existing methods and equipment must be had before any real improvement can be expected. It is my firm belief that in this instance above all others it is necessary to build the efficiency and smokelessness into the equipment in such a manner that its performance will be entirely independent of both skill and interest on the part of the operative. To attempt to educate every man, woman and child who periodically throws coal into a domestic furnace would be literally impossible. Much can be done, however, if we could teach the householder the simple essentials of alternate firing, which I have explained at length in the above mentioned paper. This would go a long way toward making the domestic furnace problem more satisfactory, as well as efficient and smokeless. Many will argue, and with good reason, that the domestic fuel should be prepared coke and with this I agree up to the limit imposed by the practical considerations of quantity production, price and the possibility of marketing the by-products. It will be obvious that if enough raw coal should be processed to provide all of the required domestic fuel that the amount of by-products recovered during the coking process would be so great that there would be little or no market at any price which would justify the manufacture of coke. If the by-products were wasted they would not only be a tremendous economic loss, but the price charged for the coke would probably be so high that the market would be limited, and this would defeat the very idea of the whole thing. Much can be done, however, in advancing the use of coke, but I believe that much more extensive and careful experimentization should be had in order to determine the right size and quality of coke for the various domestic furnaces. If coke were to be developed for extensive domestic consumption it is more than probable that the coking process should and could be stopped at a point where the volatile content of the coke would be sufficiently high to permit of prompt ignition and combustion in low draft installations. If the volatile content were from five to ten per cent a very different kind of coke would be produced from that which is now produced with perhaps one per cent of volatile. A skillful manipulation of this feature would make coke adaptable and satis-

Jan 1, 1925