TIDBITS OF INFO- MINER INTEREST

rehab · TIDBITS OF INFO- MINER INTEREST

EMJ 1922

Underground Mining in City Construction

CYNICISM, and perhaps disappointment, prompted the definition of a mine as a hole in the ground owned by a liar. Curiously enough, despite the frequent evidence of corruption in city politics, no one has associated the holes made in the ground and leading to and under a modern city with mendacity.

In the current issue of “The American Magazine” Mr. Richard Kent submits an amazing array of figures that illustrate the immensity and complexity of the subterranean construction completed and pending in and around the island of Manhattan. Open-cut excavation, the sinking of shafts, the driving of tunnels, the use of explosives, provision for adequate ventilation —these are all within the field of mining engineering; yet one finishes the article with the impression that no member of the mining industry has participated in this work.

A cramped municipality must of necessity go underground to provide conduits for traffic, for mail transport, power, artificial light, and heat, and telephone and telegraphic communication. Two hundred million dollars ‘was the cost of the Catskill Aqueduct—to bring water to New York City. And’, quotes Mr. Kent.

“At its lower end, for a distance of fifteen miles or more, at a depth of from thirty to eighty feet, this aqueduct will pass under the city—under Central Park, down Broadway and Sixth Avenue, under Fifth Avenue at Madison Square, under the East River at Delancey Street to Brooklyn; then under the harbor ‘to Staten Island U’ This record of construction in itself is a gigantic mining enterprise.

More and more is passenger traffic in the city being deflected from the streets. New York possesses nearly two hundred miles of underground railroad tunnels and nearly 800 miles of track. In parts this is so far from the surface ‘that elevator shafts are necessary to connect train platforms with the street sidewalks above. Vehicular traffic into and out of a congested region such as Manhattan Island is being facilitated by tunnel approaches.

Witness, for instance, the Holland Tunnel connecting New York and New Jersey recently completed at a cost of about $50,000,000. In essentials of design and construction it was a mining engineering job. Perhaps the average mining engineer could learn something from the elaborate system of forced-draft ventilation that keeps the atmosphere in the tunnel free from a dangerous proportion of poisonous fumes—the result of an exhaustive research conducted by engineers on the staff of the U. S. Bureau of Mines at Pittsburgh.

Underground mining in a city serves purposes other than for traffic and water supply. Pneumatic transport of mail appreciably diminishes congestion in the streets above. The New York system of tubes is 54 miles long, connecting various main post offices and stations and handling 70 tons of mail per day. Gas main and sewer conduits are also to he found in the labyrinths of the city’s arterial system, but complexity reaches the apparent limit in telephone wires. One special task that confronted a New York telephone company is quoted by Mr. Kent: A subway line proved a serious obstruction. “So two shafts were sunk on either side of Seventh Avenue, down to bedrock, twenty-five feet below the tracks of the subway, fifty feet under the surface of the street.

Sappers—with picks, shovels, and dynamite—worked beneath the subway trains laden with passengers, and eventually cleared a U-shaped passage, 150 feet long, eight feet wide and eight feet high. ‘More than a third of a million separate telephone wires now lie in the tunnel.”

Increased power demands, improved living conditions, the need for the artificial adjustment of atmospheric conditions in the larger buildings—these and many other factors are making it necessary to precede building construction with extensive excavation work.

An immense open cut is being completed near the publication offices of the McGraw-Hill organization, the work being accompanied by all the familiar practices and paraphernalia of modern mining. It extends to 75 feet below the sidewalk; and five floors of space will be provided for the varied supply and service requirements of a large modern hotel.

The story of opportunity and achievement in the laying out of a modern city, or bringing an old one up to date, is a fascinating one, but no feature is more important than the provision of means for underground transport and communication. In this field the mining engineer should distinguish himself. He and the associations which represent him should “get into the picture.” He is familiar with the problems involved and is capable of solving them. His breadth of experience should point the way to speedy performance, accurate result, and miiiimum construction expense.

rehab · MINING BOOMS LETTER TO THE EDITOR EMJ 9-23-1922

Emj 9-23-22

Mining Booms

THE EDITOR:

Sir—The recent discussion concerning the boom at Oatman reminds me of others. Most mining booms have their scene of action in a gold- or silver-bearing region, the chance of making money quickly being much greater there than in a base-metal district. Generally, rich ore is discovered at one point, after which the ground surrounding it is staked for miles. Companies are organized by the score, and brisk trading and absurd rises in the price of shares follow.

As the discovery claims continue to reveal more ore, the adjoining neighbors may find a little ore, whereupon the market booms and goes wild. This is why mining is termed a gamble by the unthinking public, especially by those who have been stung.

On the other hand, in the aggregate a good deal of money is collected by the companies formed, machinery is purchased—helping business generally—work is provided for a large number of officials and men, and the ground is prospected in every direction, permitting the geology to be studied. No doubt the state corporation departments are kept busy watching the prospectuses and organization of the many companies, this being one of the safeguards for the speculating public.

What have been the results of booms in the past? Omitting the early activity on the Rand, and the rush to the Klondike, we can look back on a number of booms within the last thirty years. Cripple Creek, as a starter, has yielded gold amounting to about $400,000,000. The names Cresson, El Paso, Golden Cycle, Independence, Portland, Strong, and Vindicator have become almost household words among mining men.

Next comes Kalgoorlie, in Western Australia, where British capital was sunk in millions sterling, but the total yield from an ore somewhat similar to Cripple Creek runs apace with the latter, and is equal to $380,000,000. No better mines have been developed than the Associated, Golden Horse Shoe, Great Boulder, Ivanhoe, Kalgurli, Lake View Consols, Oroya, Perseverance, and South Kalgurli.

At about the same time was a boom at Waihi, in New Zealand, but the only mine that was opened—the Silverton— closed later, leaving only the present mines—the Waihi and Grand Junction, which had been opened earlier.

Early in the present century Jim Butler discovered what has resulted in Tonopah, a silver district that has yielded $140,000,000—including gold—and such mines as the Jim Butler, Montana, Tonopah Belmont, Tonopah Extension, Tonopah Mining, and West End. Following Tonopah came Goldfleld, wherein the Goldfleld Consolidated alone yielded $78,000,000.

In northern Ontario next came Cobalt, another boom in silver. But what has it produced? Such mines as the Buffalo, Coniagas, Kerr Lake, La Rose, McKinley-Darragh-Savage, Mining Corporation group, Nipissing, Temiskaming, and Wettlaufer, a total of over 320,000,000 oz. of silver and many millions in dividends.

Porcupine was next the scene of a gold rush, resulting in the Dome, Hollinger, McIntyre, Porcupine Crown, and Schumacher, and an addition of over $75,000,000 of gold bullion to the Dominion’s once small total. Kirkland Lake had a considerable flutter, but has produced the Lake Shore and several other worthy producers.

A small yet reckless boom caught Australians again at Bullfinch, in the West, but only two mines of any note became producers out of the large number of companies bearing the names of various songsters, and they are now closed.

Rochester, in Nevada, then came along, but the rush for this silver district was quite mild, yet we have the Nevada Packard, and the Rochester Mines and Combined, now the Rochester Silver. Oatman, Arizona, started one of the largest booms in recent years, fully 200 companies being organized to prospect there for gold, depth being necessary.

Prior to this rush, the Tom Reed and Gold Road mines had been consistent producers, but when the United Eastern opened so well the excitement started. The really tangible result of the Oatman business is the United Eastern and Big Jim, now combined, and one or two other small producers; also the present discussion in the Journal-Press.

The boom in oil in Wyoming, copper at Jerome, in Arizona; oil shale in Colorado, and the feverish excitement in Texas oil might be included here.

This brings us, late in 1917, to the scene laid at Divide, six miles south of Tonopah. This was early known as the Gold Mountain district, but had been almost neglected until, in the Tonopah Divide mine, rich silver ore was found. By September, 1919, about 300 companies had been organized with: funds aggregating $3,000,000. Shares on Bush Street, San Francisco, soared to all sorts of prices.

The net result is the Tonopah Divide mine, a regular producer, and opened to 1,400 ft.; also one or two other small producers. Anyhow, the public had a run for its money- About the same time (1919) a highly respectable boom started in the Salmon River district of British Columbia, yielding the great Premier silver mine, which is distributing a half million every three months; also the Dolly Varden mine.

Then a wild boom started in 1919 at Hampton Plains, near Kalgoorlie, Western Australia. Visions of another Golden Mile, much speculation, geologic discussions and development of the Hampton Celebration, whose mill and cyanide plant recently started work, about sum up that affair. When and where will the next boom be?

As a whole, most booms in the past have been productive of many real mines and much valuable technical knowledge—both mining and metallurgical—but the reckless gambling on the part of the public, whereby it loses money, has given mining the odium of being a gamble; and while the public does not pause to consider the issues, considerable blame should be attached to the non-technical press, which rather urges—perhaps ignorantly and innocently by means of its news items—the speculation in unproved mining districts.

Pittsburgh, Pa. M. W. VON BERNEWITZ.

rehab · TRUE TALK FROM A MINER EMJ 9 23 1922

September 23, 1922 Engineering and Mining Journal-Press

True Talk from a Practical Miner

THE EDITOR:

Sir—I have read with interest in a recent copy of your journal some one’s remarks on the shortage of skilled and intelligent miners, and maybe a few remarks by a miner might help clear a few doubts.

In the first place, it might be well if young engineers were required to serve an apprenticeship on the muckstick and machine. I don’t mean a summer vacation but several summers and winters. I’m acquainted with several young mining school graduates, and they seem to think the proper place to get experience in mining-is either to keep time on the surface or watch the boys come out of the mines.

A technical education may be good, but judgment in mining and an understanding-of miners can only be gained by practice of the one and actual contact with the other. There is a Chinese proverb that used to receive consideration in dealing with miners: “If you employ a man, trust him, and if you can’t trust him, don’t employ him.”

In this day and. age they spot your holes, give you the direction in which to drill them, and issue you a certain amount of powder to blast them with. In the hole that I am at present laboring in, there are four types of drilling machines in use in seventeen distinct stages of dissolution.

A miner spends considerable time hunting for a machine and rig, then more time hunting for wedges and blocking; working one stope one day and another-the next; receives orders to stope out ground several feet above the foot wall, and is presented with a jack-hammer, which all intelligent miners think much of, and ordered to take up bottom the next day.

One reason for shortage of miners is the one man to a machine rule. I mucked eight months in order to get a job tending chuck, and tended chuck for a year before I had a chance to handle a machine and powder-on my own hook. I was a very proud young buck the first day I got hold of a crank, but I’m not so proud now. Any fifteen-dollar-a-week clerk can travel in circles that I can’t travel in. A dirty miner is one individual to be avoided at all times except on payday, and then he should only be tolerated so long as his money lasts.

There are a few things that mining companies might take note of that would tend to increase the number of intelligent miners. Some of them are: A certain amount of respect for the intelligence that some miners possess. Also, practical as well as technical men for general managers, superintendents and so forth. An intelligent miner hates like the devil to do work that is unnecessary and impracticable. Another thing is to foster pride in good work rather than to seek to have a large amount done in a slipshod manner.

The attitude of the mine management toward employees is indicated very clearly to employees by conditions in the change room and the quality of food served in company boarding houses where those things exist. Also where the company observes the ordinary laws of sanitation and ventilation, as well as safety laws, the employees have more of a tendency to do likewise.

Another thing is Rules and Regulations for Employees:
Rules should be sensible and reasonable and should be absolutely enforced. An employee who breaks rules and isn’t penalized loses respect for rules and the management that makes them.

Fred MOENCK.
Tonopah, Nev.~

rehab · MINING TIDBITS THE MINING JOURNAL 12 15 1930

TIDBITS OF INFO

MINING JOURNAL, DECEMBER 15, 1930

“The Western Borax Company at Daggett, CA, is making additions to its plant. Development is being carried on between 700 and 800 feet below the surface, and the veins are from 50 feet to 100 feet high. Some of the Borax is as clear as window glass.” Rehab notes: many of these borax workings were located on the perimeter areas of Calico; one being directly north of the agricultural station on I-15 southbound.

Where have we all heard this before?
“Prospectors retain Mineral Right in Death Valley Area:
E S Giles, of Goldfield, NV, consulting engineer and surveyor, has been advised by the United States Land Department that the recent withdrawal of lands in the Death Valley area will not affect the Mineral Rights of Prospectors. Under the provision of the act, the lands shall at all times be open to exploration, discovery, occupation, and purchase under the United States Mineral Laws.

The area withdrawn for a new national park development, which includes a large part of Death Valley, extends from Death Valley Scotty’s famous ranch in Grapevine Canyon, to within 3 miles of Trona, CA. It includes the old mining towns of Ballarat, Greenwater, Panamint, and Skidoo.”

rehab · MINING TIDBITS THE MINING JOURNAL 6 30 1931

THE MINING JOURNAL JUNE 30 1931

NATURAL GAS NOW FLOWING TO DOUGLAS COPPER SMELTERS

Natural gas for fuel is now being delivered to the copper companies in the Bisbee-Douglas district of Arizona, following the completion of the pipe line connecting the copper fields with the natural gas fields of Texas. Phelps Dodge Corporation has altered its furnaces to make possible the change from oil to gas fuel, while Calumet and Arizona Mining Company has built an entirely new furnace.

This 294-mile pipe line was constructed by Western Gas Company from El Paso, Texas, to Douglas and Bisbee, Arizona, and to Cananea, Mexico. It is of 12-inch welded steel pipe, and was constructed at a cost of around $6,000,000. The actual laying of the pipe line was handled by Bechtel-Kaiser Company, Limited, of San Francisco.

Construction was started on February 16, with contracts calling for its completion by August 1. It has, therefore, been completed a I most two months ahead of schedule.

Under ordinary service conditions it will be operated under pressure varying from 800 to 600 pounds per square inch, delivering approximately 33,000,000 cubic feet of gas daily at Douglas. However, it may be operated at a pressure of 750 cubic feet per square inch, delivering at that pressure 58,000,000 cubic feet of gas.

Construction of the pipe line was made possible by the long-time contracts signed by Phelps Dodge Corporation, Calumet and Arizona Mining Company, and Cananea Consolidated Copper Company. Both gas and copper companies look on the new project as a means of stabilizing fuel costs in the copper district.

MILL CONSTRUCTION PROPOSED FOR SAN ANDREAS, CALIF., MINE

Exhaustive tests are reported being conducted by Los Angeles metallurgists on ore from the Ford mine, near San Andreas, California, looking toward the erection of a reduction plant on the property.

F. A. Mansfield and J. B. Ferguson, real estate and mining men of 301 Quinby Building, Los Angeles, recently acquired this property, formerly developed by the Calaveras Development Company.

J. E. King, superintendent in charge of operations, has reported that good progress is being made in the new development work being undertaken. He estimates approximately 800,000 tons of gold ore of an average value of $7.50 per ton already available at the property.

A NUGGET From G00DSPRINGS, NEVADA
“I want to congratulate you on the Journal (The Mining Journal). I regard it as the best mining publication in the whole country, especially for westerners. The arrangement is so complete, it touches us all and gives us information concerning the things and places in which we are interested and is a big help to the country.”
—Jess Knight.

rehab · SAFETY FUSE USE AND CARE MINING JOURNAL 8 15 1931

Safety Fuse, Its Selection, Storage and Use
By JAY B. STONEKING, Secretary, Coast Manufacturing Company, Livermore, California.
The proper selection and use of safety fuse may mean the difference between profit and loss, and between safe working conditions and serious accidents.

Safety fuse consists of a center thread surrounded by a train of black powder and enclosed in various wrappings of textiles and waterproofing materials. Its purpose is to carry fire at a continuous, uniform rate to the cap or explosive charge. The center thread has no influence on the burning rate but is simply used to aid in securing a uniform flow of powder into the fuse. The powder, which is the live element in the fuse, is protected by the textiles and waterproofing coats from abrasion and water. This envelope is also used to secure a uniform burning rate, to prevent intercommunication of fire between adjacent lengths of fuse, to prevent flashing or running of the fire, and to minimize the chance of setting fire to the charge of explosives by sparks from the side of the fuse before the fire has reached the fuse end.

Selection of Fuse.
The choice of a fuse to use depends on the work and conditions under which it is expected to operate. A fuse which is to be used in very wet work, under water, or where water drills are in use, should be amply waterproofed; consequently, fuse for use in wet work must be highly water-resistant as compared to one which is to be used only under dry or slightly moist conditions. For cold climates a very pliable fuse in which the waterproofing will not become brittle and fracture should be used. The same holds true for use in mines which are very cold, Taped fuses are more susceptible to becoming brittle when subjected to cold than are cotton countered fuses, hence, the countered varieties are recommended for cold climates and cold conditions. For very hot climates or in hot mines or for open quarry work, such as block holing, where the fuse must at times be exposed to the direct rays of the sun, a use is required which will resist heat and for these conditions one of the white countered paper taped fuses is recommended.
Inasmuch as the paper taped fuses give off a minimum of side sparks on burning and a minimum of smoke and gas, this type of fuse is recommended for use in inflammable dynamites and explosives and for use underground where ventilation is poor. Where the practice in vogue of loading bore holes at a particular property involves the bad practice of lacing the fuse through the priming cartridge or otherwise causing kinks or sharp bends, a fuse which will give the maximum resistance to this sort of treatment should be selected. In some work the color of the rock formation may influence the selection of a fuse with regard to its outside finish. A white finished fuse is more easily distinguished against a dark colored rock than is a black finished fuse.

Transportation
In transporting fuse care should always be taken to see that it is protected from rain and moisture. Any contact with excessive heat such as exposure to the direct rays of the sun, storage near steam pipes, boilers or stoves, should be avoided. Since oils, paints, gasoline, kerosene, distillate, and similar solvents will penetrate through the waterproofing and deaden the powder, fuse should not be placed where there is any liability of these materials being splashed or spilled on the fuse during transportation.

Storage
What has just been said regarding oils and similar materials applies as well to fuse storage. Numerous cases have occurred where coils and reels of fuse have become damaged by being stored where any of the above named solvents could come in contact with the fuse. The slogan “Keep Cool and Dry” which is printed on all fuse wrappers should be adhered to. A rough test for dry storage is the well-known salt test. It consists of a shaker of ordinary non-iodized table salt being exposed for about 48 hours in a storage place. If the salt is not materially affected by the moisture then the place should be satisfactory for fuse storage.
As regards temperature, a place which always remains between 45 and 70 F. is the best for fuse. It is not wise to store fuse underground, as the underground air is usually very humid and even cut fuse lengths should not be kept under these conditions longer than 48 hours. The old stocks of fuse should always be used up before beginning on a new incoming shipment. This precaution is necessary because the burning speed of the fuse slows somewhat with age and the waterproofing coats have a tendency to lose their elasticity and become more brittle with age.

Cutting and Crimping
It is always a wise precaution to insure that the fuse is warm before uncoiling. A temperature of at least 65’ F. is desirable. On fuse which has been exposed to the air for a considerable time at least ¼ inch should be cut from the end so as to obviate trouble from damp fuse ends. In measuring lengths, the fuse should not be wound around a nail or peg since these sharp bends are very liable to cause a fracture in the waterproofing coat. The cutting implement should have a clean sharp blade as this avoids smearing the waterproofing over the end of the powder train with consequent trouble from misfires. The fuse should be cut squarely across and inserted in the cap immediately after cutting.
Instances involving misfires have been investigated which show that the trouble was due to the loss of powder from the fuse ends before being inserted in the cap. In some cases this shaking out of the powder was produced by slapping the fuse ends roughly upon the cutting table or bench. In other cases, the fuse was hung over a peg or nail with the ends down where they were flipped about by the wind and by persons rubbing against them in passing. No foreign matter of any kind should be allowed in the cap and a damp cap, or caps, which may be suspected of having absorbed moisture, should not be used.
In crimping the cap on a fuse length, the fuse end should be seated lightly and firmly in contact with the surface of the fulminate in the cap. Eliminating such old methods as crimping with the heel of a pocket knife blade or with the teeth, there are three general types of cap crimpers in use which make distinctive crimps. The broad flat crimp has two ridges on opposite sides of the fuse for vents. The four-segment crimp has four slight ridges at equal intervals around the fuse for vents. The ring crimp may or may not be vented. Some crimpers of the ring type do not have a stop, hence, the jaws may be closed so tightly as to completely sever the fuse, This type is not recommended.
The reason that practically all crimps are vented is because fuse contains air which is forced in advance of the fire into the cap and unless this air is allowed to escape through the vents in the crimp a back pressure will build up against the fuse spit and seriously interfere with its effectiveness.
Sometimes on a black finished fuse having a relatively soft outside surface a crimper of any of the above types, which is of too small diameter, will squeeze the outside waterproofing into the vents or ridges and seal them up, making an un-vented crimp.
In wet work it is necessary to seal the cap crimp with some sort of waterproofing material. This act in itself closes the vents, resulting in a non-vented crimp. In the ease of all waterproofed crimps— in fact, in any non-vented crimp, exceedingly great care should be exercised to see that the fuse powder in the end of the fuse is in actual contact with the fulminate in the cap. Gaps as small as 1/16th of an inch will give serious trouble from misfires.
In some cases where a black finished fuse was used and trouble was perpetually encountered due to not carefully seating the fuse end against the fulminate, the condition was corrected by substituting a hard white-countered finished fuse in place of the black finished. The white- countered finish does not squeeze out into the vents, hence, practically always leaves a full vented crimp. However, when this crimp is waterproofed and the vents sealed, the same condition applies as mentioned above for black fuse and the same care in carefully seating the fuse against the fulminate should be observed.
Materials used to waterproof the crimp sometimes cause trouble. A too liquid compound will run down into the cap through the vents, sealing over the fulminate surface and cause misfires. A crimper that makes too loose a crimp will sometimes allow the same thing to happen. Greases and oils, paints, which contain gasoline, benzenes, carbon tetrachloride, and similar solvents, should not be used to waterproof the cap crimp. These materials will penetrate through the fuse waterproofing and into the powder, giving rise to very weak end spits or even complete failure to burn.
The capped fuse lengths when not immediately used should be hung over a broad curved surface or laid flat on a shelf. A number of causes for misfires have been traced to the hanging of capped fuse lengths over small pegs or rails. These pegs or nails cut into the waterproofing and materially weaken the water-resistance of the fuse at this point. Another instance was encountered where the capped lengths were tied in bunches, formed into coils, and the coils stacked high, one on top of the other, in a warm room. In this case, in the bottom coils, where the fuse strands crossed one another, the waterproofing had been cut into, similar to the instances mentioned above where the lengths were hung over nails.

Attaching Fuse to Primer Cartridge
Those methods of attaching the capped fuse to the cartridge of dynamite known as “lacing,” “half-hitching,” “reversed primer,” and “center end priming” which cause sharp bends in the fuse near the cap should be avoided. Any sharp bend has a tendency to fracture the waterproofing and admit water into the powder at the fractured point. Two methods known as the “string tied method” and the “rim end method” are to be preferred since these cause no sharp bends in the fuse. In the string tied method, the hole is punched slantingly through the side of the cartridge and angling toward the center of the opposite end, the capped end being inserted in the hole and the fuse tied to the cartridge with a string. In the rim end method the hole is started in one end near the rim of the cartridge and angled toward the center of the opposite end. These methods leave the fuse at one side of the bore hole and avoid kinks which might be caused by the tamping stick or succeeding cartridges placed in the hole.

Loading and Spitting the Round of Holes
In charging boreholes for dependent or rotation firing, such as in drift or tunnel rounds, the primer cartridge should be placed far enough down the hole to avoid being cut off or thrown out by the explosion of the adjoining hole. The same number of cartridges should be used above the primer cartridge in holes in the same round and the tamping should be uniformly tight in each hole. This is advisable because the burning rate of fuse is affected by the length and tightness of the tamping, hence, this should be kept as equal as possible on all holes which are to be fired in rotation. The fuse should be held taut at one side of the hole while loading and tamped so as to avoid kinks and cuts in the fuse. There should always be some stemming on top of the explosive so as to avoid any possibility, during the lighting of the fuse, of sparks coming in contact with the explosive. Stemming material containing sharp particles should not be used as these sharp particles may cut through the waterproofing and cause misfires.

In spitting or lighting a round of holes where each series is dependent on each other and must be fired in rotation, the fuse end should be trimmed or cut off, varying the length cut off so that the holes which are intended to fire first have the most trim or longest length cut off. The amount to cut off depends upon the length of fuse being used. A good average rule is to trim ¾ inch per foot of fuse length being used. This would mean that if a 6-foot length were being used, the lifters or holes to fire last, would have no trim. The back holes would have an 8-inch trim. The breast holes and the relievers immediately above the lifters would have a 6-inch trim and the cut holes, which are to fire first, would have a 9-inch trim. The holes should then be lighted in the order in which they are expected to fire.

Misfires
Where misfires are encountered, a careful and thorough investigation will usually develop the cause of the trouble, which can then be remedied. The lengths of fuse with caps attached taken from misfired holes generally tell the story. In examining these misfired holes it should be noted whether there are any indications of sharp bends in the fuse near the capped end, which might have been produced by such practice as lacing the fuse through the cartridge or some similar method. If the crimp is waterproofed, the nature of the material used for waterproofing should be noted. The caps can be pulled off and examination made to see whether the fuse has been cut squarely or on a slant and whether the fuse end was in actual contact with the cap fulminate.
Damp fuse ends usually show a minute particle of the center thread remaining in the fuse end. A leaky crimp wilI sometimes show moisture in the cap and the powder in the fuse end will generally be wet. If the fuse has burned completely through and there is no moisture evident, a blackened fulminate surface indicates that a dirty or dull blade had been used in cutting the fuse and smeared waterproofing across the end of the powder, Loss of powder from the fuse ends before crimping generally results in a slightly blackened fulminate surface while the inside surface of the jute threads in the fuse end are hardly charred. Greases, oils and similar materials penetrate into the threads surrounding the powder train or even into the powder itself, volatizing ahead of the fire and re-condensing on the surface of the fulminate which will show a bad discoloration, being brownish and blackened.

If the fuse has not burned completely through, it should be un-ravelled carefully, taking off successive layers until the powder is reached. If wet powder is encountered, near any sharp bends, it will indicate that the waterproofing has been fractured at this point. If wet or caked
powder is found in the fuse along the ore hole at a considerable distance above the cap, the waterproofing may have been fractured by kinking in tamping, cut by sharp tamping particles, by the fuse not being properly warm before uncoiling, by having taken a half turn around a nail or peg while cutting the fuse lengths, by hanging the fuse lengths on a peg or nail after being cut, or by bunches of coiled capped lengths having been stored on top of one another, allowing the strands of fuse to cut into one another. If a very dull looking powder is disclosed, it may indicate having become oil soaked or overheated,

Premature Blasts
In the daily checking of the manufactured product, millions of feet of fuse have been burned under close observation. This observation has never disclosed a so-called “flashing” or “running” fuse Inasmuch as there have been reported instances of blasts going off prematurely, the above observation necessitates the placing of the cause of these premature blasts on something else than that of a running fuse.

If a fuse length is pounded on a flat surface so as to fracture the enclosing envelope longitudinally or is cut open with a knife longitudinally, a flash or run will result. Fuse that has been roughly trampled underfoot on sharp rocks might give rise to a similar condition. The lack of tamping or covering over an explosive charge might result in a premature blast due to the setting of the charge on fire by the curling back of the lighted fuse, spitting into the explosive. Sparks from a punk or rope lighter might also drop into the explosive and set it on fire. Coiling up of the fuse around the mouth of a hole and laying a sharp cornered rock on it to weight it down might cause crossings of the fire from one strand to another where the rock had cut into the adjoining strands. The coiling up of the excess fuse length and shoving same into the mouth of the hole might fracture the fuse coverings and cause a spit into the explosive or cause a cross-fire from one strand to another. In a tamped hole a badly kinked or cut fuse might side spit into that portion of the explosive near the mouth of the hole, setting fire to same and resulting in a premature blast before the fuse had burned down to the cap.

Delayed Blasts
In the millions of feet of fuse which have been burned under observation in checking plant product, there has never been a case found of a piece of fuse apparently going out, smoldering for a time, and later rekindling and burning through. In all observed cases, where the fire apparently died out, it had been in fact, completely extinguished, never to again rekindle.
Since delayed blasts have been reported and the above observations indicate that the cause is not in the fuse itself, the following explanations may be of benefit.
The cap not being tightly crimped has allowed the fuse to pull away several inches from the cap in loading. The end spit from the fuse has set the explosive afire, which later detonated.
Weak or moisture-damaged caps have set fire to the explosive which later detonated.
Delayed blasts occurring for a considerable length of time after they should have fired most probably are due to a misfired hole which a later ground squeeze or ground movement has fired by the pinching of the cap or explosive. In other instances some explosive with cap may have been cut out of one hole by the explosion of an adjoining hole and thrown out in the muck pile, this explosive or cap later might be fired by the sliding of the rock in the pile or by falling rock from the roof.
While it is not maintained that defective fuse has never been manufactured, every effort has been made to insure a perfect product being shipped. It can readily be seen that various things may happen to fuse after it leaves the factory and that good careful handling coupled with good blasting practice will be amply repaid in freedom from trouble and misfires.

rehab · PERFECT SAFETY AT JEROME, AZ TMJ 6 30 1929

rehab · 4 STEPS TO MAKE A MINE TMJ 6 30 1929

JUNE 30, 1929 THE MINING JOURNAL

Topsy

By LETSON BALLIET, Consulting Engineer, Tonopah, Nevada. The mining industry, like Topsy,
“Jest Growed,” but larger profits would result were the four essential steps in making a mine followed—prospecting, exploring, developing and producing.

If a prize were offered for the best synchronized and most efficiently handled business, it would NOT go to the mining business. Probably the big circus is timed the most perfectly from the advance agent to reloading after the night show, and perhaps the 5 and 10 store is somewhere close to the top-contenders for the prize, but there are two business operations that wouldn’t have a chance at the money—mining and cement manufacturing.

Both of them, like Topsy, “jest growed.” Nobody ever planned on ‘em being much account when they started, but when they “jest growed” too big for their clothes, they were pieced out, patched up, and added to, as “good enough for Topsy,” and if that doesn’t fill the bill, they “jest pick up some old things” that have been thrown away, or discarded as obsolete, out of date, or worn too badly to be worth fixing. Anything is regarded good enough for the Topsy Mining Company.

J. B. Hagin is credited with saying:
“I wouldn’t have a mine that wouldn’t stand mismanagement,” but today mismanagement may be just the difference between failure and success. What other business could even cause such a statement to be thought of?

Compare this statement with conditions at the new Carreras factory, where humidity and temperature are so controlled as to manufacture its own climate; in perfect lighting arrangements with the machinery so automatic that the company makes $2,000 net profit per year per worker on the payroll from the superintendent down. The workers receive good pay, and are supplied with the very best working conditions. Instead of making a profit by pinching it out of the workers’ pay, they make it with mechanical economics and good working conditions.

Leaving a loop hole, through which any mine manager can crawl by saying:
“He doesn’t mean me,”—I wonder how many mines were laid out for the tonnage they produce, and are mechanized and supplied with working conditions that give the workers a chance to produce the maximum tonnage per man without undue fatigue. I wonder how many mines dare publish “tons per man on the payroll.”

Cutting miner’s wages has never increased the output per man on the payroll, nor lowered the cost per ton. It may fool the directors for a while, but taking money from the workers’ pay to bolster a superintendent’s reputation for lowering costs never works out in the long run. When a wage cutter loses his job, he seldom can get another of that kind. The proper way to lower costs is to mechanize the work with automatic machinery and higher paid workers to operate it.

There is only one Carreras factory, and perhaps one mine that leads in efficiency, and maybe a few others that approach somewhere near the leaders, but we have a right to wonder why others do not strive to reach the same point of efficiency.

There is but one crop in any mine. No matter how big it may be, when it is gone it is gone. It would seem that the incentive should be to harvest that crop at the lowest cost per ton, instead of being satisfied with any cost so long as it shows a profit. Why not get as much of the single crop into the bank account as possible, and as little as possible into the expense account?

It has been asserted frequently that “a good mine makes a good manager,” and “a man in charge of a mine so rich that it pays in spite of the management makes the manager a big reputation,” but not every promoter is able to find a foolproof mine of which he can elect himself manager. Even if such a mine were a profit payer over the costs, would any other business be satisfied if the profits could be more?

Consider the case of the Hypothetical Mining Company, paying 20 per cent quarterly. The published reports showed the operating costs as $9.52 per ton, handling 500 tons a day. Nothing with less than $9.52 in recoverable value could be taken out. It had to be left as “waste.”

When the administrative office expense, travel expense, officers and directors salaries were paid, there was nothing left for the stockholders after the ore values dropped below $14 a ton.

The Hypothetical Mining Company then stopped paying dividends with the “eyes picked out of the mine,” and its best grade of ores gone. Under $14 a ton the records began to show red ink in the profit and loss column until the final shut down, notwithstanding that an attempt was made to keep going by cutting wages.

Subsequent examinations show that the mine still contains more than a million tons of ore in sight that will average from $7 to $11 per ton, which the previous manager has left standing as “waste.”

Suppose a management, who could have mechanized the ore handling to $7 a ton, had been in charge, the profits on the three million tons that have already been taken out would have been $2.52 a ton larger, and the stockholders bank accounts would have been greater by $7,500,000 that was wasted in useless expense—and at least a million tons with $2 or $3 profit could be on top of the ground, instead of hopelessly buried in the abandoned -workings. There would be approximately $9,000,000 or $10,000,000 more metal floating around the world somewhere for the benefit of mankind that is now unobtainable.

Building the Dump
If we go into any mining district, or any mineralized region, we see countless dumps, large and small, around the collar of the shafts, or at the entrance to tunnels. I wonder if any one ever stopped to figure what it costs to put a carload of waste over the dump.

Some years ago, I watched from my office window the top man on the dump of a neighboring mine, and my own top man. I made some changes in my top work as a result of the object lesson that chance put within view of my window.

The conditions were as follows: The wage scale for top men was $5 per day. Eight hours contains 480 minutes, therefore, I was paying slightly more than 1 cent per minute to the top man. So was my neighbor. Both properties were developing, hoisting only waste. The rock was hoisted on a cage in a one-ton car. The top man removed the loaded car, replaced an empty car on the cage, shoved the loaded car to the edge of the dump; where it was emptied, and returned to the collar.

When things were running smoothly this operation required eight minutes. Sometimes there were long periods of waiting. At times the top man moved track, occasionally a car got off the track or went over the dump with its load, which caused delays and required help from other employees. With these delays and the cost of rails, cars, ties, spikes, fish-plates, lubricating oils, moving track, and help from other employees, I estimated that it was costing 20 cents to 25 cents to put a car of waste over the dump after it reached the surface. There were 21 employees. The cost of operating was 56 cents a minute, including overhead and expendable supplies (those that would have no salvage possibilities).

That reminds me of an old song entitled, “There are lots of things one never learns at school.”

At one time I was a division engineer for a railroad. In ballasting I obtained the gravel from a pit, using a donkey engine and a dragline scraper. With a car spotted under a hopper, we loaded gondolas at a cost of 2 cents a yard.

A mine dump is a fan-shaped “fill” and the gravel pit was a fan-shaped “excavation.” The operations are the exact reverse of each other.

The dragline brought gravel from the ever-widening edge of the gravel pit to the central point of loading. The top man, with a car, moved the rock from the central point and dumped it at the ever-widening edge of the dump. If it were possible to have turned the dump upside down, it would practically have fitted into and filled the gravel pit.

With a dozen reels of old hoisting rope lying around, with but little salvage value, I wondered why it cost 20 cents to 25 cents per 20 cubic feet to build a dump, and 2 cents for 27 cubic feet of gravel gathered from the pit. Quien sabe? (Who Knows?)

I equipped the operations, under my direction, with an 80 cubic foot self-dumping skip, and built a bin at the shaft large enough to hold a 24 hours’ run of the hoist, if operated to its peak of capacity. Then I set a top man to empty it at such times as it needed emptying. Not only did I save top man time, but I saved hoisting time, as the skip had no waiting to do for the change of cars. I wasn’t hoisting the weight of the ears, and I didn’t have to use the cars for rock storage on the levels, nor wait for an empty to be returned. When the underground trammer dumped his car he took the same car back and there was no waiting, nor cars standing on the levels. But aside from interlocking savings, I cut the cost of building the dump more than 50 per cent.

That is only one item, and one worker’s job, but I will not be in the same class with the Carreras factory until I can take the rock away from the collar and put it on the dump by having the descending skip operate a starter that will do the job without the man.

However, that wasn’t what I started to write about. The idea I want to continue to talk about is the “jest growed” idea. We find a long drift or crosscut is confronted with ventilating problems. Maybe we have a blower, or a pressure, or suction fan installed some place. Perhaps we put in a booster fan, or a compressed air jet, and try td get along. Perhaps a branch drift or a stops needs air, and how many of us do what we should do? I have been guilty myself, and I’d be ashamed to tell you what I’ve done to “get by” and I’ve seen worse contraptions than I ever used. But we “jest growed” and “we added to, pieced out, and patched up” something that was good enough. Then we found a lot of ore and tried to take it out with the conditions we put up to find it, but I learned my lesson to figure tonnage and cost per ton before I let myself run into any Scotch economies.

Pumping water is another item that will break a company if it isn’t handled right. I was drowned out once about 30 years ago, but never again. I learned how to handle water from that experience. Not so long ago I found a graduate engineer, pumping water from a 500-foot mine (?) with three little pumps, bought second hand, with two discharge pipe lines, and operating to full capacity for 24 hours. His pumping costs and uncertainties made the job a failure, even though the ore was there.

Nobody is expected to wear this shoe if it doesn’t fit, but the object in writing it is not to see how many will blush while reading it, but rather to visualize what occurs in the starting of new mines, and the “exploring of prospects,” which then try to develop and mine ore with the prospecting equipment. Is it any wonder that we have ill advised, incompetently directed, and incompetently financed stock promotions that result in losses to the investors?

There Are Four Steps In Making a Mine

(1) Prospecting—or hunting for the place where Nature has deposited some of her mineral ores.

(2) Exploring—”Prospecting the prospect.” Finding out whether Nature made a big deposit, or a small one. Whether she deposited it in a crack, vertically, horizontally, inclined, or impregnated the formations. Ascertain size, extent, depth, trend, dip, rake and values.

(3) Developing—Planning where to open the deposit for the taking out of the ores most economically and cheaply, easiest of accessibility for the underground delivery to the outlet, and the surface handling at the outlet. Planning how to open the deposit, the equipment required, the cost of doing it and the capacity of shaft and equipment, and then executing according to plans. In short, getting ready to move the deposit.

(4) Mining—Moving the deposit from the place where Nature put it to a bank account.

The attempt to combine any two of these steps is expensive. Mining, without development, makes the cost per ton high. Developing, without having first explored the prospect to know how it should be developed, is foolish, as the deposit might be only a little thing not worth extensive development, or it might be so big that inadequate development would have to be done all over, or in some other spot.

Generally, it doesn’t require much money to explore a prospect. If it does, it is big enough to justify it, or the exploration work would have been stopped. It is not difficult to find men with money who are willing to put in a little money to explore a prospect, because the profit is large if it is big and rich. If the prospect has been explored, there is ample capital always ready to buy, or develop.

The difficulty in financing comes when the prospector and promoter want to leave out the second step, and raise money to DEVELOP the prospect that has not been EXPLORED sufficiently to give the knowledge that it justifies DEVELOPMENT.

With all this in mind I am asked: “Is it possible to outline in advance a plan of operation for making a prospect into a mine?” It is easy to outline the exploration of the prospect as defined in Step 2, which can be continued or stopped as conditions warrant.

If the exploration work is thorough and sufficient to know what is necessary to be known, I see no difficulties in the way of planning the development (defined in Step 3) with reasonable accuracy and in estimating the financial requirements.

With the development well advanced, and the exploration work being carried ahead of the development, it is easy to plan and outline the ore production, handling, and the related operations, but when the inexperienced superintendent and promoter attempt to finance—”to mine a prospect,” without taking Steps 2 and 3, I can see very grave dangers in the path of the investor. In fact, I am almost ready to say it can’t be done.

rehab · THE PROSPECTOR PROBLEMS TMJ 9 30 1929

for SEPTEMBER 30, 1929 THE MINING JOURNAL

The Prospector and His Problems

By A. C. GILMORE, Prescott, Arizona.
Paper presented at the Prescott Mining Revival.

Despite the many difficulties, the word “discouragement” isn’t in the prospector’s vocabulary.

The prospector I have reference to is of the genus derisively called Hillbilly or desert rat. In these days prospecting is not monopolized by him of the frying pan, pick, shovel and blanket roll, packed on a burro. It sometimes happens that companies, capitalized for a million dollars, ultimately turn out to be prospectors; for some of them, before they ever worked or sold a pound of ore, found that they were prospecting for the bigger fellows—the companies with scores of millions available for mining.

Hillbilly can prospect only in terms of feet; the small company digs a few hundreds of feet; the great companies are prospecting all the time, miles of drifts, crosscuts, winzes. One company in Yavapai County, had some 10 miles of underground workings before it installed a mill. But the big mines had their inception on the day when the Hillbilly found float ore and the vein it came from.

Magazine writers, with their desk in New York, claim that Hillbilly’s burro finds the ore by accident. Hillbilly’s practical, and sometimes disastrous, experience with Jack and Jenny, is that they do most of their prospecting in search of the slab of bacon and the sack of flour. Fortunately for Hillbilly, burros cannot climb a tree, nor a giant cactus.

Problem I
To get a grubstake.
In these days, as of yore, Prospector finds that the average merchant who owns the bacon and beans or the other fellows who have the ‘dinero’ think that they are doing something magnificent and munificent if they allow him $25 per month. Prospector solves this little problem by getting a job and earning enough to buy not only grub and tools, but a flivver as well.

What with cattle guards, drift fences, gasoline for sale, where formerly hay and grain and free water could be had, the burro is nearly useless. It is said that he can live on tin cans, but even Jack Burro balks at gasoline and Zerolene cans, now plentiful at what were formerly stage stations with watering troughs for Jack and Jenny. If they now get a drink, it will have to be from a hose while Prospector is reading a sign “Free water for customers only.’ So Prospector, having luckily preserved the lives of him self and family when crossing the (to him) scars upon the face of nature, called boulevards, has abandoned Jack and Jenny, mounted Tin Lizzie, and joined the rush.

Rush it is with some of them—especially the young and less experienced. Two young fellows who drifted to Prescott in a flivver said they had prospected all the way from the Mother Lode of California in two weeks. Located scores of service stations, but no veins. I recently talked with an old prospector, however, who is a mechanical engineer. He put new fangled innards into Lizzie so that she could climb out of arroyos and up steep hills, and he loaded up with water and gas, and got farther out on the desert than Jack and Jenny could go, except in a
very wet season.

He found a big deposit of manganese—but too far from road or rail. Which is, by the way, one
of the prospector’s problems after finding ore how to get it to market.

And right here, although irrelevant, (and perhaps will be deemed by some as also impertinent), I would like to remark that not in a thousand years would that manganese have been found by a mahogany-desk mine operator, nor by the mine promoter, nor by the mining stock salesman. A trip like that would mar the varnish of their limousines. So the prospector is still the advance guard of the mining industry, which in turn, is the advance guard of civilization.

The prospector discovered the metals, which have substituted the steamship for the canoe, have replaced the stone hammer and hatchet, by metallic tools of such hardness and temper that they will cut glass. And, by the way, even Tin Lizzie may be said to have been procreated by Prospector, for what would she be, and how far would she get, without the iron, manganese, copper, vanadium, etc., in her makeup?

Well, Prospector, having provided himself with grub and loaded it upon Tin Lizzie, starts out, and of course meets

Problem 2
Which is to find ore having quality and quantity warranting development.

Perhaps he finds a float in a score of gulches, digs upon as many hillsides, spends weeks or months tracing veins, panning or otherwise testing ore. Say that, by way of illustration, he eventually overcomes Problem 2; finds a big vein of free-milling gold ore, $15 a ton, 20 feet wide, 1,000 feet of ore outcropping. He knows it is very valuable, and that with the proper equipment to work it, his fortune is in that rock.

But it is two miles from a spring up on the mountain, is 20 miles from the nearest wagon road—and he is only $20 from being flat broke. He cannot ‘arrastra’ the ore, for it is a little too low grade to pay by that slow process, and the nearest quartz mill is 40 miles away. So he is up against it, so far as his individual resources are concerned. He is confronted by

Problem 3
Which is to get financial help.

Now, as a class, the prospector is not a schemer, nor a bilk. At the beginning, he is ignorant of the methods of the so-called financier, and of the financial agencies, and of middlemen. Perhaps he loses his property before he realizes that he has associated himself with human spiders who had spread their webs, and that he was the fly they were after. To escape these spiders is a difficult thing, even for the experienced. The spider is forever inventing and building new webs, or patching weak places in the old.

Our prospector goes to town, having first duly monumented, and done the initial work upon the Good Faith, and other claims. In the lobby of the best hotel he gets into conversation with Mr. Fatwad, reputed financier. “Yes, I can finance the property by forming a corporation, but I want 51 per cent of the stock,” says Fatwad.

At first Prospector thinks that, as he is owner and has thus far borne the entire burden, he should get at least one-half interest in the company’s stock. But it is explained that in consideration of the extra 1 per cent of the stock, Mr. Fatwad will pay the expense of organizing the company. Prospector is anxious to make a deal, and says to himself, “Well, 1 per cent isn’t much, anyway.” So he consents. Suggests Good Faith Mining Corporation as the name of the company. Fatwad says, “Fine! That sounds fine!” His smile indicates derision and humor, as well as pleasure, but Prospector does not notice that; is himself in excellent humor, indulges in prophecies as to the big mine they will make.

A deed conveys the property from Prospector to the ‘Company’. Prospector finds that the board of directors consists of Fatwad, Fatwad’s wife, Fatwad’s stenographer, Fatwad’s bookkeeper and Mr. Prospector. Fatwad is in control. Work is started under Fatwad’s direction. Later it is found that money is not forthcoming to pay miners and merchants.

Prospector has beautiful stock certificates, but no money. Some fine day he reads in the local paper that the company’s holdings will be sold by the sheriff at 10 a. m. at the north door of the courthouse. Prospector witnesses these obsequies —broke. Fatwad also is there, as planned from inception of this and other companies, and bids in the whole property for a debt not at all commensurate with its value.

The months pass, as does title to the ground. Prospector finds that his “Good Faith Mining Corporation” is succeeded by Merger Mines Company, Inc., a company in which he has no ownership, although still interested—as an onlooker. Prospector remarks; “That Financier Fatwad is sure a merger, all right! He merged my 100 per cent ownership into 49 per cent; did the same thing with Chuckawalla Bill’s Rattler group and with Burro Sam’s B. A. M. group, then chucked ‘em all into this Merger thing. Merger ain’t a strong enough word—I’m plumb submerged! Next time I’ll do the financing myself; organize a company at my own expense, and keep control.”

So back to the hills he goes. Locates another group, works for wages, saves about $1,000. Tries to start a company, finds he does not know how, so hires a lawyer. “You must have articles of incorporation,” says the lawyer. “All right,” says Prospector. Lawyer steps into next room and speaks with Miss Stenog, who trots down stairs. Prospector is told to come back next day. Miss Stenog goes to recorder’s office, is handed one of 16 volumes of recorded articles of incorporation, copies one of them which fits the case except as to names and dates. Elapsed time of Miss Stenog, two hours.

Next day Prospector pays $50 for the job. He is paying for about $2 worth of actual work, the $48 being for brain fag sustained by the lawyer. Then follow bylaws, and application to corporation commission for permit to sell stock. Sounds profound, mysterious, difficult to Prospector. But as there are tons of carbon copies of such documents available, Miss Stenog simply has another job of copying. Lawyer’s brain fag again assuaged. This time it cost
Prospector the savings from a month’s wages when working on a bean diet.

Prospector then goes to Phoenix, to square his company with the corporation commission. His company, like other mining companies, is, by Arizona and California laws, presumed to be guilty of fraudulent intent until proven innocent of such malicious purpose by the payment of fees to the corporation commission. Well, he pays, and gets his permit. Cost him about $100; lawyer cost him $200; is out about $800, and not a share of stock sold.

He tries to sell stock. He is not a good salesman; does not look prosperous, for he had to pay for red tape instead of for good clothes. Concludes, finally, that he will have stock sold on commission.

Sees in a reputable paper printed in Los Diablos, California, the advertisement of an outfit stating that they are prepared to conduct the details of financing new corporations. Prospector writes them. They answer, outlining their methods, but promise nothing definite. State that they cannot do so until they have threshed the matter out with him in person. Will he please come to their office and confer? His company has no money to defray such expense, but he goes. Is impressed by the handsome furnishings, the bevy of handsomer stenogs, the suavity of the manager, and the general aspect of prosperity.

Is told about the New York branch, with big clientele; and the great volume of money available in California from movie stars and retired capitalists, the manager verbally insinuating that their bank accounts are on tap for him and that he is their trusted adviser in matters financial. Yes, they have employees who are gifted writers of prospectuses and follow-up letters; in fact, have all modern facilities for conducting a stock-selling campaign.

For $1,000 they will prepare and mail such literature, and will charge 20 per cent upon stock sales made directly by their salesmen. The $1,000 is too big for Prospector’s pile, but he has $600 left. Compromise effected by cutting down amount of mail matter. Prospector hands over his $600. Receipts from stock sales are to be placed to credit of his company. Sounds fine to Prospector, so he goes back to his claims and does a little work on roads and trails, awaiting the arrival of funds.

Weeks pass; no funds arrive. Excuses and explanations from the financing agency as spacious as their offices were spacious. Prospector reads his contract critically, carefully. Finds that nothing is guaranteed except that they will write and print a prospectus, mail certain form letters, send out stock salesmen to try to sell the company’s stock.

Prospector runs across a printer friend. Is told that prices charged were very high, even if he were sure the full number were printed and mailed as agreed upon. Prospector, under an assumed name, sends for literature of other mining companies, which had, like him, contributed toward the prosperity of the financing agency.

Found a remarkable similarity in them. Printer looks them over. “A lot of pick-up in these,” says he. “Guess their printing office keeps the forms standing for the next sucker who comes along.” Prospector soliloquizes: “For Financier Fatwad, in the Good Faith Mining Company deal, I was the fly. He swallowed me whole. In this financial agency alleged attempt at financing, I am surely the goat—and now my printer friend insinuates that I am also a ‘sucker’.”
Next day he picks up the Arizona Republican, dated August 4, 1929. Across eight columns he reads a big heading: “Statistical Position of Copper Aided by Curtailment.”
This reminds him of

Problem 4
What can I do with copper prospects?
Prospector knows the copper camps of Arizona. Has studied the outcrops of the big mines. During his wanderings in remote places he has seen unexplored ground with equally good earmarks. “But what’s the use of locating it?” thinks he. “Big companies have a huge tonnage of ore blocked out. Could flood the market if they worked to utmost capacity; and I read, also, that South America, Africa, Canada have to be reckoned with—especially the cheap-labor countries. And, besides, the big companies have for years had their scouts in the field and now have mine reports pigeon-holed by the dozen.

Slim chance for me and my remote ground. The more available ground is already located—and included in those reports. If I located ground, which is even better than any ever yet found, I could not prove it to be such. It would, in these days, mean millions of expenditure. Perhaps, 20 years from now, when the mines now operating are depleted, I might sell copper claims—if, in the meantime, I had not been driven off the ground, and other goats taken my place. I mean the real, four-legged critters. Looks a little discouraging for me- as far as selling copper claims is concerned.

“But that big headline in the Republican at least strongly hints that copper will fetch a fair price for a while. Guess I’ll keep my eyes open for a streak of red oxide or glance, and ship it. The little which we prospectors send to the smelters, will not cause a break in the market. Course I’ll have to figure railroad freight rates and smelting charges more carefully than I figured with them different breeds of fake financiers, or I’ll lose labor spent in digging $80 ore.

Down in the Tucson section, I hear, the prospector can take his little jag of ore to the Chamber of Commerce. Little jags, thrown into the copper, lead, gold or zinc bin, eventually make a carload, getting the benefit of carload rates on railroad as well as at smelter. I understand that the Chamber of Commerce does a little better than break even, that the prospector gets more for his ore, and is encouraged to dig more ore—which means digging more money and putting it into circulation among the members of the Chamber of Commerce and the whole community.”

Problem 5
Where in heck are those patented claims?
Prospector, having unburdened himself to me, as above related, said that he guessed he would quit financiering and try chloriding for a while. So he went to the hills again, to find a vein suiting his purpose and within hauling distance of a railroad. In about two months he was back. “Well,” said I, “did you find that vein of shipping ore?” That started him.

Leaving out lurid profanity and much sarcasm directed against defunct mining companies and somnolent holders of mining claims, he told his latest experiences about this way:

“Sure, I found good veins, and close to towns. Picked up a promising vein one day while I was hammering Lizzie with a rock. Traced the vein about a mile and nearly fell into an old shaft. Looked as if it hadn’t been worked since the days of Coronado. Small quantity of very good ore lying around. Found out that the claim is patented, along with 11 others, and that the owner is a rich widow living in New York. Thought I might get a lease, or perhaps find ore outside the patented ground and locate it. Wrote to the widow. Her attorney replied that the ground was for sale for cash only, and that I could get plat at the land office. Wanted cash payment quicker than I could have picked it up, if the ground had been strewn with $20 gold pieces. Bet that widow is like some of your town people; will not think of those claims again until next year when the tax collector wants his check.

Those 12 patented claims were in that vicinity. But where? Might be strung out for 18,000 feet along that vein I had stumbled across. That’s over 8 ½ miles. Drove Lizzie about five miles beyond the widow’s ground. Found another good looking vein. Patented also; 15 claims this time. Found it belonged to a storekeeper. I didn’t say merchant; I said storekeeper.

Same fellow who offered me $25 a month as a grub stake. Said that he owned the claims; didn’t know exactly where they were himself, as he had bought them at sheriff’s sale. Then he said: ‘But I give you notice that if you find any good ore on them, it’s mine, and that I do not authorize you to work on them.’ Those two groups of claims not only lie idle year after year, but the indefiniteness of their boundaries acts as a scarecrow and makes prospectors keep away from their vicinity.”

Just then a mutual friend, a service station keeper and mechanic, happened along. Said to Prospector: “Looks discouraging for you prospectors since this geophysical apparatus started in on your job, doesn’t it? You’ll have to go ‘way back and sit down.”

“Did you say discouraging?” said Prospector. “Why man, the word may be in your dictionary, but not in ours. Fact is some of the first prospectors who came to this neck of the woods were more than discouraged. They were mortally killed by the Apaches, as the cub reporter would say. Have to go ‘way back, will we? Why, sure! That’s our job. Didn’t think I was going to stay here and prospect cement sidewalks, did you? And as for that geophysical contraption, it can’t claw its way through the brush without help, can it? And just maybe it will need some prospector like me to show it where the ore is. And that don’t mean I want a steady job at it—but I might work long enough to get a grub stake.”

And he went away, remarking: “Got a lot more hard problems to work. Wish I had paid more attention to my Greenleaf arithmetic when I was a boy. ‘Lot in that book about percentage and discount which I did not savvy. Might come in handy when I’m checking up one of these here smelter returns.”

“Well,” says the service station man, “I wish you good luck. If pluck brings luck, you surely deserve it. And if Lizzie gets thirsty, bring her around. I don’t charge prospectors for water—and I’ll give her big drink of gasoline besides.”

rehab · HEALTH HAZARDS FROM DUST IN MINES TMJ 9 30 1929

THE MINING JOURNAL 9 30 1929

Health Hazards from Dust in Mines

By C. O. SAPPINGTOIV, M. D., Director, Division of Industrial Health, National Safety Council

The harmful effects of dust to industrial workers, has long been known. However, through a long period of time there were no distinct statistics proving the health hazards of dust to industrial workers.

Even a few years ago there was a sharp controversy on the injury of dust to coal miners, which is one of the oldest of industries and one where dust is always a problem. The statistics, especially from some of the older countries, seemed not to support the claim of this hazard to industrial workers. Less than five years ago an expert in this field read a paper before a Mining Congress in which he asserted distinct harmful effects of dust to coal miners, and his report drew caustic editorials.

But the last few years have brought a decided change of viewpoint, and now there is seemingly quite general acknowledgment of the harmful effects of dust to coal miners. It has been explained that the previous mortality statistics relating to coal miners probably were not complete. When the coal miner did develop serious respiratory affection he would leave the coal mine, probably to die an early death; but his death would not be statistically charged against the hazards of coal mining.

The harmful effects of dust in mining and milling operation, is usually a leading subject of interest and debate at Regional and National Safety Congresses. For example, the Transactions of the Mining Section of the 1927 Annual Safety Congress give a great deal of space to such a discussion.

One of the speakers before the Mining Section of this Congress was S. W. Meriwether, M. D., of the U. S. Bureau of Mines. He stated that within the last few years the medical profession had been making a rather close study of the effects of dust. He stated, as a general conclusion, that “The higher the percentage of silica in the dust, the higher the percentage of pneumoconiosis, or lung disease.”

He explained further that since statistics showed a low percentage of tuberculosis in coal miners, many investigators had come to believe that coal dust was harmless. In order to thoroughly test this matter, the U. S. Bureau of Mines conducted a series of experiments or studies in a number of coalmines in different states. Atmospheric dust samples were studied, and X-ray pictures from 514 physical examinations were studied.

“The conclusions drawn from this work,” he states, “was that coal dust when breathed in large quantities over a long period of time, and I mean years, will produce pneumoconiosis; but that the number of men in coal mines subjected to such clouds of dust, was and is comparatively small; that is, it is largely confined to the men working on and around machinery.”

This Investigation brought out a number of interesting facts. It was found, for example, that a man entering the coal mine after 40 years of age contracted lung diseases much more quickly than a man who would enter at 20 years of age. This was found true also for the disease caused by silica dust, or silicosis. Contrary to popular opinion, hazards from lung diseases in the coal mines were found more prevalent in the white race than in the colored race. Apparently the smoking of tobacco had no relationship to this hazard. However, the diseases of whooping cough and measles did seem to have a relationship.

This investigation indicated, as suggested, of possible dust hazard safeguards, that 9 per cent of the dust of an average mine was produced at the face of the cutting of the coal. Sixty-three per cent of the dust was produced by machinery, 84 per cent by shoveling, and 8 per cent on the roadway. But, it developed that only a small percentage of the coal miners were subjected excessively to dust. This included the operators of the undercutting and over-cutting machines, shearers and loaders.

It is generally known, of course, that methods of control of the dust hazards, from a health point of view, are more simple in coal mines than in metal mines. In coalmines, one of the most effective methods of control is the introducing of water on the cutter bar of the undercutting machine, and on the shearers and loaders. This water will not only lay the dust from the machine but also wet the bottom and decrease the amount of dust produced by the loading.
A very important associated factor in the control of lung diseases among miners is sanitary and welfare measures. A large percentage of coalmines, of course, do give attention to this matter; for in these modern days such expense is usually considered a good investment making for business efficiency.

Apart from its relation to respiratory diseases, dust plays an important part in the irritation of the eyes, ears, nose, and throat. This is indicated by the extensive prevalence of these troubles among miners.

Skin irritation also is often produced by a combination of dust, sweat, and heat, even though the dust may not have any poisonous effect in itself. Certain injurious effects of dust cannot be questioned. This is further emphasized by the study of tuberculosis in relation to the dusty trades. Fortunately, it is estimated that only about 25 per cent of dust inhaled actually reaches the lungs. The greater part of the dust is expelled either by sneezing or coughing, or it is swallowed.

The disease known as “Silicosis” is probably the most important one relating to the lungs and caused by the inhalation of dust. Harmful silica is encountered chiefly in industrial processes when crystalline silicon dioxide, granite, quartz and sandstone are used. The size of dust particles has much to do with whether or not they will cause trouble in the lungs. The larger particles, which fact may be contrary to popular opinion, are the least harmful.

Some mining operations are concerned with the so-called poisonous dusts, including those of lead, mercury, arsenic and others. This kind of dust is taken up by the liver after absorption through the lungs or intestinal tract.

The ordinary dusts of mining and milling operations are classified as non-poisonous, and usually they do not contain silica. They are irritant dusts, but they do result in the replacement of the elastic tissue of the lungs with an unyielding scar tissue and this condition is a predisposing factor in the development of lung diseases.

Preventive measures for dust hazards are always important. In one western mine, for example, the superintendent became alarmed with the discovery that they were receiving at their hospital every day, four or five men operating machines, who were troubled with hemorrhages. The mining superintendent immediately went underground to personally investigate the situation. He found that the mining machines were necessary to carry on their work, but he developed the plan of using water on the cutter bar of the machine and the difficulty was at once eliminated. It is estimated that the use of water in coalmines will reduce the dust in the air by 75 to 80 per cent. The elimination of this dust also lessens the hazard of cold dust explosion.

An interesting problem related to dust in the air is air contamination. For example, an excessive amount of dust might have the same general effect as if the oxygen of the air were reduced from 20 to 16 per cent. A mining official reported, for instance, that he had noticed that on the west side of his mine, where the air had been humidified through a sprinkling system, his workmen seemed more lively in the evening when they quit work than the men on the east side of the mine where the air was not humidified.

In another mine it was found that in the drilling of a six foot hole, about 60 per cent of the dust was formed from the first two inches of the hole. Thus, by wetting the spot for this hole 60 per cent of the dust was eliminated. The greatest problem was found to be to get the men to start digging in a wet place.

The superintendent of this mine summarized the prevention measures which he had taken to eliminate dust. First, all of their drilling was wet. Second, they wet down twice a day the stopes and laybys or partings where the cars were switched. Third, there was no blasting in the mine while the men were on theground. Fourth, they provided adequate ventilation, getting pure air up to the face of the operations and getting impure air containing the dust out of the mine.

This official stated, as his opinion, that he was “firmly convinced that it would take four or five times as long to contract silicosis in our mines at present as it would have four years ago.”
This official further stated that “a man who has contracted silicosis, or silicosis complicated with tuberculosis, is not the individual he once was and consequently he is more subject to accidents. He hasn’t the “pep,” he hasn’t the vitality, and a rock that he could have dodged three or four years ago will come down and bump him off with greater ease once he has contracted the disease.”

Wherever there is a noticeable amount of dust produced in a given industrial process, as in milling and mining operations, the important steps in the investigation on the dust hazard would be:
1. The quantitative estimation of crystalline silicon dioxide in the sample of air breathed by workmen.
2. A chemical analysis of the dust sample.
3. A computation of a frequency distribution of the particle size.
4. Examination of workmen for physical effects.

The United States Public Health Service, through its study “The Health of Workers in Dusty Trades,” suggests the following protective program:
1. Physical examinations for the purpose of determining general physical conditions.
2. Special physical examinations to determine the problem of specific disease of the respiratory system.
3. Sickness records of the nature and severity of disabling illnesses.
4. Control of occupational environment.

With reference to exposure to dust, Dr. Edgar L. Collis calls attention to the following points:
1. Inhalation of all forms of dust is accompanied by diminished power of chest expansion.
2. Diminished power of chest expansion so produced is accompanied by high blood pressure.
3. Animal dusts (apart from the pressence in them of disease germs) when inhaled, produce relatively fewer effects than do vegetable and mineral, dusts.
4. Vegetable dusts, when inhaled, tend to produce a type of chest affection best described as asthmatic.
5. Of mineral dusts, those composed of calcium salts are least injurious.
6. Inhalation of mineral dusts which do not contain free silica tends to produce irritation of the upper air passages and respiratory diseases other than a fibrous reaction.
7. Inhalation of mineral dusts which contain free silica is associated with an excess of scar tissue formation, and excess which bears a direct relation to the amount of free silica present.
8. In general, dusts appear to be more injurious as their chemical composition differs from that of the human body or from the elements of which the body is normally composed.

In summary, there is a constant study of the problem of elimination of dust as a health hazard. Much has already been accomplished toward the solution of this problem, and it is certain that much more will be accomplished.

rehab · ACCIDENTS FROM FALL OF MEN & MATERIALS TMJ 9 30 1929

THE MINING JOURNAL for SEPTEMBER 30, 1929

Accidents Due to Falls of Men and Materials

By F. D. CANJVON, Assistant Mining Engineer, U. S. Bureau of Mines; Washington, D. C.

While falls of ground take the heaviest toll in mine accidents, many other causes must be considered and every effort made to avoid them.

Introduction

In metal and non-metallic mineral mines during the 15-year period 1911 to 1925, 30.17 per cent of all fatalities and 18.57 per cent of all injuries were caused by falls of rock or ore from the back or roof or from the wall; 1.24 per cent of the fatalities and 11.05 per cent of the injuries were caused by rock or ore while loading at the working face; 6.66 per cent of the fatalities and 2.49 per cent of the injuries resulted from men falling down a chute, winze, raise, or stope; and run of ore from chute or pocket caused 1.48 per cent of the fatalities and 1.98 per cent of the injuries. Hence, accidents due to falls of men and material caused 89.55 per cent of the fatalities and 84.06 per cent of the injuries in these mines.

Accident prevention can best be assisted by each company’s preserving complete records of accidents classified according to cause and rate per thousand or 10,000 shifts. A systematic method of recording accidents and the employment of graphs or charts will be helpful to the company’s safety department in analyzing the causes of accidents. The purpose of this publication is to analyze data on accidents caused by falls of men and material in metal mines of the United States, and to suggest methods of preventing or reducing such accidents.

Falls of Ground

Among the numerous causes of fatal and non-fatal accidents in mines, falls of ground takes the heaviest toll. More than one-third of the total accidents in metal mines can be attributed to falls of ground in some form.

The accident records of a large mining company show that in five years there were 18,931 days lost by miners who were hurt by falling ground while drilling. Although the majority of these accidents were slight, there were three fatalities and several serious accidents. It is probable that a large percentage of these accidents were avoidable. Many miners are negligent in properly barring-down loose material before commencing to drill, and the vibrations set up by the drilling cause rock to fall.

Often the ground contains treacherous slips or seams and there are places where ground of this kind is in such large blocks that it will not sound “drummy” when tested. The boss or safety engineer, being familiar with the character of the ground, should warn new workmen of such danger. In some instances accidents could be prevented if proper timber were available for the miner to make his assigned working place safe. The alert boss will always make it a point to have proper material on hand for his men to work with.

There are many unavoidable accidents which no amount of barring-down or timbering will prevent, such as the breaking off of portions of rock where holes are being started. To avoid injuries resulting from this type of accident the Morenci Branch of the Phelps Dodge Corporation has designed a guard, which fits over the handles of stoping machines, and all miners are required to wear goggles when starting holes in order to avoid eye injuries. Another stringent rule of this company is that no one is allowed underground without a “hard-boiled hat.”

In stopes and drifts where it is necessary to use timber, the use of stringers to the breast when there is not room for timber will aid in the elimination of many roof fall accidents. At the Nevada Consolidated Copper Company’s mines in Ray, Arizona, either stringers are used, or else drifts are timbered to the breast. At the Miami Mine, Miami, Arizona, a unique method of using stringers to avoid the necessity of a bridging piece is employed. Iron hangers fit over the caps and a hook on the lower end supports railroad rails, used in lieu of wooden stringers. It is a very easy matter to cover these rails with plank.

Barring-Down

No other operation in mining requires the same amount of physical energy as “barring-down”; this is especially true if it is necessary to use a long bar. The fact that a man soon tires when prying with an eight or ten foot bar, in an endeavor to dislodge a rock which he knows should come down, is probably why many miners cease prying, and trust to luck that the rock will stay up, or that if it does fall they will not be under it. There is much to learn about the knack of barring-down in such a manner as to avoid unnecessary risk.

The careful man will clear away any obstruction that may cause him to stumble if he has to make a quick step. He will then sound the hack and select a safe place to stand while barring-down. Miners often start to trim down loose rock while standing on floors so “cluttered up” that a quick step could not be made with safety. Instead of sounding the ground, they pry down the first loose piece, they see, which often loosens the key rock and the miner is buried in the fall of ground that follows.

In some open stopes, the back is carried so high that barring-down can be accomplished only by working from ladders. Wherever it is possible, though, barring-down should be done while the men can reach the back by standing on the muck pile. This is especially important in horizontal cut-and-fill, and in aIl stopes.

There are times when a miner cannot bar or pick down loose rock due to the lack of tools, for some mine managers try to economize by not furnishing enough tools. Men will be seen working with bars or picks which are so dull as to be not only discouraging, but impossible to use effectively. A trip through the United Verde Mine, Jerome, Arizona, will furnish a contrast to the method just mentioned At various places throughout the mine, supply depots are maintained where miners may at any time procure tools.

Educating and instructing the miner in the proper method of doing work is not any easy task. However, it must be accomplished if worthwhile progress is to be made in accident prevention. Some companies have adopted a method of giving new men a period of instruction before
they are put to work in the face. Many have found strict discipline necessary to make some men regard the violation of safety rules as a serious offense.

Slide of Rock, and Rocks Falling Down Piles

Most accidents from rocks falling down piles, and from slides of rock, are caused by rolling boulders. Accidents of this nature usually result in injury to the feet and legs. Shovelers who fail to keep the rock pile pulled down and work in front of an almost vertical pile of loose rock, face the greatest danger. It is a simple matter from time to time to take a pick and pull down the muck pile, thereby in a large measure reducing the danger of accidents from rolling rocks.

Hard-toed shoes are also a great asset in the prevention of foot accidents. The Morenci Branch of the Phelps Dodge Corporation has found it necessary to furnish men working on grizzlies, with a guard to protect the shins and instep, in addition to the safety shoes.

Slabs or Rocks From Back and Sides

As a result of 4,059 metal-mine accidents from slabs of rock falling from the back or sides, there were 160,465 days’ lost time. One per cent of these injuries were fatal; 18 per cent caused injuries that resulted in more than 14 days’ lost time; 25 per cent caused from one to 14 days’ lost time; and 56 per cent caused no lost time other than the day of the injury. This amount of lost time would be equal to taking 521 miners, who ordinarily work 800 days a year, out of the industry for a period of one year.

Although it is improbable that all these accidents were avoidable, yet with proper precaution in the use of stulls and barring-down or timbering where necessary, unquestionably many of them could have been avoided. Miners often contend that there is a greater hazard in working in a rill stope than in a square set stope, yet the accident figures of a large company show there is little difference.

Although it is natural to conclude that more injuries from falls of ground occur in stopes and raises than in drifts and crosscuts, figures of this same company show that in proportion to the number of men working in these places, more men are injured in drifts and crosscuts than in stopes and raises. Apparently, when a man is working in a place he considers dangerous, he is alert and gives attention to his work.

By calling attention to hazards a boss can do much to prevent accidents; this has been proved by the fact that although bosses on opposite shifts have had their men working in the same places and consequently in practically the same hazards, a period of several months has elapsed without any injuries occurring to the men under one boss, whereas every month some member of the crew under the boss on the opposite shift was injured. Education and enforcement of regulations pertaining to the safety of men is the best method of overcoming accidents caused by carelessness.

Rocks Falling in Manways and Shafts.

In a five-year period, 649 men in one district were injured by falls of rocks in manways, probably resulting from three main causes, namely: (1) Defective chutes, (2) failure to keep loose rock cleaned out of manways, and (3) carelessness in covering manways.

Defects such as a lagging coming off a chute are unavoidable, but it is also inexcusable to continue to use a chute in this condition. Nevertheless, such a condition often exists indefinitely without repairing. In order to free rock hung in chutes, miners many times will cut a hole in a chute, and if they do make any repairs it is generally a makeshift job. In repairing chutes where square-set timber is used, it is generally more satisfactory to nail cleats to the posts to hold the boards used for the patch rather than to nail a short piece of board over the hole.

Keeping manways free of loose rock is not difficult, if the policy of doing things right when mining is followed. If, in a mishap, rock accumulates in a manway, the rock should be cleaned out, and the manway repaired before permitting it to be used as a traveling way.

Negligence in covering the top of man-ways when work is being done over them allows a great deal of rock to fall into manways. Many times miners blast over or near the top of a manway without taking the proper precautions to cover it. In order to gain access to air or water lines, many men pull a lagging from the top of a manway without previously clearing away the loose rock. The man who fails to cover a manway properly, or to remove the covering from one without first clearing away loose rock, is a liability to any organization.

Much of the rock, which falls in shafts, is the result of carelessness. Measuring pockets are used in conjunction with many skip chutes, so that if the skips are kept clean and ordinary caution is exercised, overloading of skips can be avoided. However if the cage tenders overload the auxiliary pocket, an overloaded skip will result. Where the type of gate used on the auxiliary pocket will permit, some cage tenders leave the gates on the main chute open, thereby making it possible for one man to do the work of two, but at the same time the purpose of the measuring pocket is voided. When cars are dumped directly into skips, overloading is due to carelessness on the part of the cage tenders.

With proper bonnets and doors on cages, the possibility of injury by falling rocks can be materially reduced. Failure to keep the lining boards in good repair between the service compartment and the compartments where rock is hoisted increases the danger from falling rocks. There should be doors with positive latches on all stations in shafts where rock is being hoisted. If a solid door will interfere with ventilation, one of heavy mesh wire can be used that will not interfere with ventilation and will still prevent rock or material from falling on the station.

Rock Falling in Chute.

Rock falling in chutes generally injures repairmen who have to work inside the chutes. With proper precaution, accidents of this nature can be practically eliminated. The top of the chute should be covered and a sign placed near indicating that men are in the chute. If feasible, the chute should be cleaned before any work is started when there is danger of objects falling from above. If the chute cannot be cleaned, a bulkhead should be put in to protect the workmen, and if a chute is covered on top, it is advisable to use a bulkhead for additional protection.

Falls of Tools and Material

During the ten-year period from 1917 to 1926 there were 26,650 men injured non-fatally while handling tools and timber. In this report the interest is centered chiefly in injuries from falling objects, but it is not possible to get the exact data as to how many injuries from handling tools and timber were caused by falling objects.

It is of interest to note, however, that of the 77 men injured in the mines of the Anaconda Copper Mining Company of Butte, Montana, during 1928, it was generally the injured party who left tools or timber where they would later fall on him. The elimination of accidents of this kind can only be accomplished by training the individual workers; no mechanical safeguard can be made to function in this respect.

It is with this type of accident that the training of miners invariably and automatically to make their working assignment free of all unnecessary hazards, counts most and will do the greatest good. The use of illustrated posters should do a great deal toward safety education.
The practice of throwing drill steel down manways or lowering it with a rope has resulted in many accidents. The use of a suitable “steel boat” will tend to prevent mishaps from this source.

Falls of Person

During a ten-year period from 1917 to 1926, 5,285 people were injured by falls on the surface at metal mines. During the same period 7,8162 underground injuries occurred. Data is not available to show the causes of these falls.

Falling Through Floors

In a five-year period during which over 11,000,000 shifts were worked, 308 men were injured by falling through floors in square-set stopes. No fatalities resulted from these fails, but 73 of the injuries were severe enough to incapacitate the injured persons for 14 days or more, 111 caused a loss of one to 14 days, and 124 caused no lost time except the day upon which the accident occurred. A total of 4,711 days were lost because of these accidents. That proper precaution would have prevented these accidents is believed to be a conservative statement.

Guard rails surrounding openings in the floor will prevent many falls. The use of cap lamps in lieu of hand lamps will prevent men from groping around in the dark who would not trouble to pick up their hand lamps. Care in laying floors will do more to prevent men from falling through floors than any other factor. Where small “caps” are used and the floor lagging does not have a sufficient hold on the cap, a “scab” or cleat nailed to the cap will often remedy the condition. By wedging, or nailing floors in place, the lagging can be prevented from moving. If, when men are entering a stope, they will give heed to the condition of the floors, put up guards where necessary, and be especially vigilant after blasting, as the concussion of the blast may have displaced the lagging, there would be a noticeable decrease in the number of accidents from men falling through floors.

Men Falling in Chute.

In most metal mines the policy is to use grizzlies over all chutes and guardrails around the chutes. This is in contrast to the practices of some twenty years ago when a chute generally was a yawning cavity 5 feet square, or even of much greater dimensions, with no grizzlies or guards to warn the miner of the presence of danger. At that period the acetylene or “carbide” lamp had not replaced the candle as a method of illumination for mines. That numerous accidents occurred from men falling in chutes at that time is not surprising, but at present most accidents of this nature are the result of infraction of safety regulations.

The openings between grizzlies should not exceed 10 inches according to present regulations. Often to facilitate work, or rather, to avoid it, miners or shovelers increase the size of these openings, so that in the event of a misstep there is greater danger of falling into the chute. Many men working in raises will take the grizzlies from a chute before blasting in order to save the time it takes to free the gnashes, and when they again enter the raise and proceed to bardown, replacement of the grizzlies is neglected.

In some places gnashes are not used. This is especially true if the boss is not concerned about safety or has an aversion to climbing raises. Probably on the whole, less supervision is given raise-men than any other class of underground workmen, and it is for this reason that they become lax in observing safety regulations.

There are places where it is impractical to use such a small opening in grizzlies that a man could not fall through. To meet such conditions on some of the waste passes in the United Verde Mine, men working on the grizzlies are required to wear a safety belt. When repairing or lining chutes there is always the possibility of falling. This can be overcome by using a good substantial staging to work from, and where this is not feasible a safety belt should be used.

Falling in Manways

An average of 800 men are hurt every year by falling in shafts, chutes, and man-ways. Falls in manways can be traced to defective ladders, to lack of ladders, to being overcome by gas or heat, to trying to climb ladders while carrying objects preventing the free use of both hands, and to several other miscellaneous causes. There is always the possibility of stepping into the opening at the top of a timber slide, or ladderway, in a stope, if guards have not been erected. When ladders are kept in good repair, and sollars and rest platforms, are put in at points not to exceed 80 feet apart, there is not much danger that a miner will fall unless he has been overcome or does not have the free use of his hands.

The United Verde Mine at Jerome, Arizona, have boxed in the timber slide, installed rest platforms and sollars, and “staggered” the ladders. In addition to these precautions, gratings are used over the top of the timber slide and ladderway, and guard rails are also used.
Proper ventilation prevents men from succumbing to gas, and it should have a cooling effect that will prevent prostrations from heat. The use of auxiliary blowers and flexible tubing has proved very successful in ventilating places which have impure or excessively hot humid air.

Fall of Men in Shafts

Accidents to men from falling in shafts are not common, but do occur. Many of these can be traced to men falling from buckets in shafts. In many instances it would be possible to use a cage in conjunction with a bucket. In places, equipping such a way as to enable men to use the cage instead of riding the bucket, the use of the cage should be compulsory. The provision of suitable gates on cages will eliminate the danger of falling off cages, but this is true only when the gates are kept closed; it is not uncommon to see cage tenders riding on a cage with all the doors open.

When working on ladders or stagings, a safety belt should be worn by workers if there is any doubt as to their security. All shafts should be guarded on the surface with a gate in preference to a guard rail. In most cases the platform around the shaft collar is covered with iron sheets which, when wet, become very slippery, and there is great danger that men will slip and fall under the guard rails into the shaft.

Gates should be used on all shaft stations and are preferable there, for the same reasons as they are on the surface. Shaft gates as a protection from falling rocks and material have already been discussed. Proper illumination around shafts is very essential and care should be taken to have lights where they will give the maximum benefit.

Men Falling in Open Stopes

Furnishing men with safety belts and insisting that they be used, will eliminate many accidents from falls. Education and proper supervision are necessary to make men use safety belts, as the men have a tendency to disregard such equipment unless forced to use it. It is only too common to hear of an accident that would not have happened if the man had put on his belt.

By the purchase of such equipment, the management of a mine acknowledges its necessity and at the same time admits the hazards of the occupation. When bosses and safety inspectors observe men deliberately ignoring the use of safety equipment, disciplinary measures should be used to insure the prohibition of further infractions of general safety practices.

Physical Fitness for Mining

In many instances there is doubt as to what incentive possesses a man to do many of the things he does, and from which he suffers injury as a result. In mines where no physical examination is necessary upon employment, it would be a very simple matter to hire a man who had a defective vision, is hard of hearing, or who has other physical disabilities. It is certain that a man with defective vision or impaired hearing is at a disadvantage.

Those who are not mentally alert will be more likely to be injured, than the men with active minds. Those who, due to age or a previous injury, have been rendered less agile than the average man, cannot move fast enough at times to avoid injury. Physical examinations would probably do a great deal toward showing up defects that, in time, could be proved to be the basic cause of accidents. A miner hard of hearing probably will not be aware of ground working in time to heed its waning. Defective vision may cause a man to sustain injuries from many sources.

Ventilation

The ventilation of working places will have a great bearing on accident prevention. In a hot, humid place, a man becomes fatigued and has not the endurance, or the will, to do the work that he could perform under better conditions; he will have a tendency to let all unnecessary work “slip” or to take a chance.

In some instances there is apt to be oxygen deficiency, which has the effect of making the miner less alert. Too much attention cannot be given to seeing that a mine is properly ventilated. Because 100,000 cubic feet of air per minute is entering a mine does not necessarily mean that men are not breathing vitiated air, or that the air is being properly distributed.

The question has frequently arisen as to what connection physical examinations, ventilation, and lighting have with accidents. In accident prevention, it is at times necessary to find the fundamental cause of an accident. A man may fall down a manway and be injured; he is injured by a fall without doubt, but if time were devoted to a more minute investigation, in all probability, it would develop that proper ventilation was not maintained in the raise, and the man was overcome with gas. To prevent recurrence of such accidents, the ventilation would have to be improved.

Lights

One mining company, in studying accident prevention, found that poor lights were the cause of many accidents. In order that the acetylene lamps might give a better illumination, a special reflector was obtained, and metal polish furnished, so that the reflectors could be kept bright. The appreciable reduction in the number of accidents was attributed to the improvement in lighting.

The electric safety lamp is one of the safest and best means for furnishing the coal miner with light. This type of light has the same intensity at all times, which is not true in strong air currents of lamps depending on fuel for open flames. Proper illumination of working places is so important that any time given to it can be considered as a valuable step in the right direction in accident prevention. There is no question that the up-to-date electric cap lamps give a much safer and more dependable light than any form of open lamp used in mines.

Conclusion

Probably the majority of accidents are the result of carelessness on the part of the workman and of the supervising official or officials. Men working in raises are given less supervision than any other class of underground employees, and these men become careless. Safety belts, hardboiled hats, safety shoes, safety leggings, goggles, and similar safety clothing reduce accidents. Guarding shafts, cages, chutes, and winzes, and properly timbering these places, aid in accident prevention. If those in charge of the mine management supply such safety devices as may be available, encourage the wearing of various kinds of safety clothing, and in addition promulgate safety regulations; they place themselves on record as being whole-heartedly in favor of safety, but there will be little if any reduction in accidents unless strict observance of safety practices is demanded and enforced through constant supervision. If strict supervision is given all workers, accidents from falls of men and materials will be practically eliminated.

rehab · ROCK AND MUD FLY SAFETY NOTICE TMJ 9 30 1929

rehab · TERRIBLE EDITH MINE RESCUE, IDAHO TMJ 10 15 1929

THE MINING JOURNAL

HECLA CREW RESCUES THREE TRAPPED IN TERRIBLE EDITH
Three miners, Carmen Pattrie, Jess Kerr and Russell Anstaugh, were rescued from a tunnel in the Terrible Edith mine at Murray, Idaho, by a crew of men from the Hecla mine, who plunged through flames at the mine portal and through swirling smoke until they reached the barricade behind which the imprisoned men crouched. The rescuers, after locating the miners, returned to the mine entrance for gas masks for the three men and brought the men from behind the barricade which they had erected against smoke that whirled into the workings from a fire at the mine portal.
The fire originated in the company’s barn and in its sweep destroyed the company headquarters’ building, garage, bunkhouse, cookhouse, blacksmith shop and compressor, inflicting property damages to the extent of about $80,000.

rehab · LETHAL ROCK GASES IN MINING DISTRICTS TMJ 10 15 1929

THE MINING JOURNAL

ROCK GASES FORM HAZARD IN CRIPPLE CREEK DISTRICT

The occasional occurrence of irrespirable gases in the mines of the Cripple Creek, Colorado, Mining District, has resulted in at least 35 deaths and considerable financial loss, and has been in part, the cause of the closing down of certain mines. These gases still form a hazard to life in the mines of the district as well as occasionally interrupting work. An investigation of the matter has been made by the United States Bureau of Mines in cooperation with the Mine Owners’ Association of Cripple Creek and the Colorado State Bureau of Mines.

The irrespirable gases are a variable mixture of nitrogen, carbon dioxide and usually oxygen. The usual percentage of carbon dioxide is 5 to 19 per cent, with the balance principally nitrogen.

Gas occurrences bear a definite relation to barometric changes, a falling barometer bringing the gases into the mine workings, and a rising barometer resulting in the recedence of the gases into the open spaces in the rocks. The most serious gas occurrences accompany periods of very low barometer.

Tests show that the Cripple Creek rock gases are of combined atmospheric and rock origin; they are essentially air depleted of more or less if its oxygen to which carbon dioxide has become added. This carbon dioxide results from the interaction of mine water and the minerals, chiefly the carbonates, in the district rocks. These gases are being formed at the present time, and a considerable reservoir of them exists in the open spaces in the rock strata and vein fissures.

The occurrence of irrespirable gases in metal mines is not limited solely to the Cripple Creek district; similar gases have been noted in Utah, Nevada, California, Montana, Oklahoma, other mining districts in Colorado, and in Europe and Australia. These gases have, however, proved a more serious mining problem in Cripple Creek than in most of the other mining districts.

The breathing by men of air containing considerable amounts of carbon dioxide and depleted of considerable oxygen has definite detrimental physiological effects. Where possible, the oxygen content of the air by volume at all working places should be at least 20 per cent and carbon dioxide content not more than 0.5 per cent.

The mines in the Cripple Creek District depend mainly for their ventilation and dilution of gases, on natural air circulation, supplemented by the exhaust air from drilling operations and occasionally by auxiliary blower (or exhauster) fans. A few mines use the pressure system, putting pressure upon the mine air and strata and to a certain extent thus holding the rock gases within the strata.

The pressure system of gas control is effective in holding back rock gases in a small mine, or portion of a mine, if the connections to other mines or parts of the same mine are tight enough to hold the fan pressure. It has little value in cooling a hot drift, as it tends to hold heat in; similarly the dissipation of blasting gases by this method, is difficult and often ineffective.

The small blower and exhauster with metal or canvas pipe to working faces has been found reasonably effective for the ventilation of small mines or parts of a mine; friction and air leakage curtail its usefulness very materially for pipe lines of 16 inches or less in diameter and over 1,000 feet long. The volume of air delivered by such fans is small and they
Have, in some cases, failed to take care of the rock gas problem satisfactorily.

There is no practical chemical means of absorbing the rock gases. When a drift is driven through loose, gassy ground, the sealing of such ground by the application of cement with a cement gun would seem feasible.

Gas control and the adequate dilution of large volumes of irrespirable gases has been solved in other districts by mechanical means of ventilation. Such mechanical ventilation has been obtained by a large air capacity fan located usually at the surface and supplemented, where regular coursing of the main air circulation to all working places was not readily feasible, by auxiliary underground fans and air tubing.

Similarly, surface fan installations having an air volume circulation capacity of 10,000 to 60,000 cubic feet per minute and supplemented by auxiliary underground blowers, either electric or compressed air driven, would be the ideal arrangement for the Cripple Creek District Mines. Such complete installation is one to be considered practically only in the wide extension of existing mines, the opening of new mines, or the reopening of old mines having a bad gas history.

The Bureau of Mines recommends the driving of frequent connections between levels of mines, the extension of the use of properly installed blowers and tubing for the ventilation of stopes, raises, and long drifts, and the placing of doors and bulkheads at advantageous points for the proper diversion of the naturally available or artificially induced air circulation.

Protection against the Cripple Creek rock gases cannot be had by the use of any type of gas mask. Self-contained oxygen breathing apparatus offer reasonable protection to wearers if worn by trained men, under good leadership, and if travel in them is done in unobstructed, level, or nearly level, passages and for not more than 1,000 feet from respirable air. Hose masks with hose leading to a fresh air supply offer protection to their wearers also, but their usefulness is limited to the short distance, which a hose can be used to conduct air at breathable pressures.

More detailed information is given in Serial 2865, “Rock-Strata Gases in the Cripple Creek District and Their Effect on Mining,” by E. H. Denny, K. L. Marshall, and A. C. Fieldner, copies of which may be obtained from the United States Bureau of Mines, Department of Commerce, Washington, D. C.

rehab · A I M E MEETING IN SF, CA TMJ 10 30 1929

THE MINING JOURNAL FOR OCTOBER 30 1929

A. I. M. E. WELCOMED TO THE SAME SPOT AS IN 1899

Nearly 500 delegates and friends registered for the 138th annual meeting of the American Institute of Mining and Metallurgical Engineers held at San Francisco, October 7 to 10. The group included some of the nation’s most prominent engineers, famous for research in geology and metallurgy.

The delegates were formally welcomed by F. W. Bradley of San Francisco, president of the institute, who called attention to the fact that in 1899 the organization was welcomed on the same spot, then the old Palace Hotel, which was built with money won from the Comstock mines and its brick work reinforced with old hoisting cables from the Comstock mines. The new Palace Hotel now occupies the ground.

William E. Colby of San Francisco, attorney and national authority on mining law, in his address stated that government control of mineral development is inevitable. Special mention was made of the situation which might be brought about in the mining world through carrying out of the Hoover administration proposal to transfer to the several states the surface rights to the remaining 200,000,000 acres of public lands.

Other speakers during the three-day session were:
Charles W. Merrill, former president of the University of California Alumni Association;
M. L. Requa, chairman of President Hoover’s oil conservation board;
George Otis Smith, director of the U. S. geological survey;
Dean Frank H. Probert of the University of California College of Mining and Metallurgy;
Professor C. K. Leith, geologist of international importance;
T. J. Hoover, dean of the college of engineering at Stanford University;
and Scott Turner, director of the United States Bureau of Mines.

October 10, the fourth day of the convention, about 250 boarded the President Jackson and the Korea Maru for Tokio, Japan, where they will be in attendance at the World Engineering Congress, held under the auspices of the Kogakkai, October 29 to November 7.

rehab · US GOV SILVER PURCHASES DISACCORD TMJ 10 30 1929

THE MINING JOURNAL FOR OCTOBER 30 1929

TIDBITS OF INFO- MINER INTEREST

MINING BOOMS LETTER TO THE EDITOR EMJ 9-23-1922

TRUE TALK FROM A MINER EMJ 9 23 1922

MINING TIDBITS THE MINING JOURNAL 12 15 1930

MINING TIDBITS THE MINING JOURNAL 6 30 1931

SAFETY FUSE USE AND CARE MINING JOURNAL 8 15 1931

PERFECT SAFETY AT JEROME, AZ TMJ 6 30 1929

4 STEPS TO MAKE A MINE TMJ 6 30 1929

THE PROSPECTOR PROBLEMS TMJ 9 30 1929

HEALTH HAZARDS FROM DUST IN MINES TMJ 9 30 1929

ACCIDENTS FROM FALL OF MEN & MATERIALS TMJ 9 30 1929

ROCK AND MUD FLY SAFETY NOTICE TMJ 9 30 1929

TERRIBLE EDITH MINE RESCUE, IDAHO TMJ 10 15 1929

LETHAL ROCK GASES IN MINING DISTRICTS TMJ 10 15 1929

A I M E MEETING IN SF, CA TMJ 10 30 1929

US GOV SILVER PURCHASES DISACCORD TMJ 10 30 1929