Los viejos tiempos - The old times | History of the locomotive | Topics on mechanics | Español - Un tesoro enterrado : historia de la explotación minera del carbón de piedra .

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The enormous coal production towards the 1900's in the nearby of all the industrial active centers of the world, destined to start up the machinery of all the Humanity and to put in movement the trains and ships , which interchanged the productions of all the races and all climates, was a completely new thing. The old world did not know anything about the soft coal, and it did not do, therefore, practical use of it. About two thousand years ago the British got to know the use the mineral coal, and the Romans learned it from them. The Anglo-Saxons used the soft coal for domestic aims, and England appears to be the first country in which this circumstance is mentioned in an indubitable way, being the Anglo-Saxon Chronicle the manuscript where the fact is registered. England has also the first historical data in which the principle of the operation of this mineral is mentioned , registered in a letter of privilege by Henry III who granted in 1259 to the inhabitants of Newcastle to make excavations with the object to extract coal of the fields of his castle. But during hundreds of years later , the use of coal was considered, at least in London, as a luxury, an offense and a danger for the public health, being prohibited the use it when the Parliament was in functions, and put under onerous taxes at all times.

The gradual rise of the use of the soft coal in the Modern Age

Long trains of delivery trucks loaded of coal waiting in the ports of embarkation for the the consumption of great cities, as it was seen in the Port of Baltimore towards the 1900's.

The explanation of this phenomenon is that there is no necessity of soft coal in a country of simple life, with abundant available firewood and without populated cities. Why sould have to confront the men in the past the work and the danger to excavate the soft coal from the dark depths of the Earth, when with much less work could them cut a tree? . Only when the forests were disappearing and the cities were increasing in number of inhabitants , the necessity forced the men to fight against the calamity of the lack of fuels and to face the not well well-known dangers of the mine, a battle that since then the human being has been fighting constantly.
The great extension reached by London was the fact that made imperative the coal exploitation . And by year 1605, about 400 ships of small tonnage were employeed in transporting soft coal from the mines to the great city. The tax on the soft coal, that had been a prolific resource for the State treasury in time of the Stuart, was reduced in the reign of King Williams III. From the middle of century XVIII, the coal consumption grew quickly, due to the use of coke instead of the vegetal coal for the iron smelting, and the introduction of the steam as a driving force to move the steam engines, both fixed ones and locomotives, as well as the use of the gas as illuminant fuel , stimulated this consumption. In United States of America , the coal deposits, near Richmond (Virginia) were discovered circa 1701, and the mining operation began in 1750. The anthracite was used for the first time in 1793, but the mining operation of the coal in great scale really did not begin until the year 1820. The coal, that had been despised before , like a sleeping resource during innumerable centuries, began to be a luxury, a prohibited means, about four hundred years ago, it got to be an increasing necessity three centuries ago, and the world realized about two hundred years ago that it was one of the first materials on which the progress of the Humanity depended, worrying to the most foresighted spirits, submerging them in anxious speculations about the probable duration of this mineral resource before the inexorable demands of the mechanical industry. It seemed as if a furious and tremendous competition had developed in some regions to exhaust it quickly, seen the phenomenon in the perspective of the historical ages; but, whatever it is the end, the conquest of the mineral coal will stay as a great chapter of the human effort to obtain a fuel to keep the Civilization going on , until in the middle of century XX, the power plants were diversified, in nuclear, hydraulic, aeolian, petroleum, etc., beginning a greater dependency on the petroleum.

The history of how the soft coal was obtained in the 1900's is the history of the overcome difficulties, and there is no chronicle more impressive than this one, in which it is important the work to know the nature and to reach a deal between the Nature's laws and the life of the man, because with the coal extraction the Man have entered in a new sphere of work in the solid Earth crust gradually, with dangers that are accumulated as he advances, and in that each new lesson is learned at the cost of disasters and of losses of lives.

In the beginning, the soft coal was exploited like the quarries, in opened sky, or horizontally so to speak, like a person who digs easily making a grotto, removing the material towards the surface and following the vein as if he moved through an ample tunnel. In those times women were used at the exit of the tunnel to carry the coal in baskets on their backs. The first difficulty that was found was the water presence, that, as long as it was deepened in the carboniferous layer, it was accumulated in the place of the work. When it was necessary vertical wells to continue operating the veins, every time deeper and richer, the difficulty was increasing, because the terrestrial layers that contained water were cut in the advances, and the water pooled at the bottom. At first , to remedy this disadvantage, it was used pumps, and chains with pipes moved by a wheel, as a chain dump, that worked by means of horses ; but many mines were flooded and dominated by the water, and consequently the man had to retire considering himself defeated. Things changed, however , in 1705, when Thomas Newcomen invented world's first successful atmospheric steam engine, that worked elevating the water by means of compressed air which enabled mines to be drained to greater depths making them economically possible, and which, circa 1712, got to reach such a degree of effectiveness, that it began to control the action of the water in the flooded mines and to allow that wells were excavated until greater incomparable depths.

The hard to beat mortal enemy of the mines .
But the increase of depth in the mines unveiled a new danger. Until then the water had been the enemy, and in such amount it appeared, that in some districts it produced a moving sand layer, almost impossible to excavate it through . The ground, at the bottom and around the well, was solidified by the action of the cold, and in this case its extraction was facilitated, after which the obtained orifice was covered with iron tubes. When the mines, nevertheless, had passed this region of humidity and it was reached the drier layers, where it was found a much more deadly enemy, and which has still not being definitively defeated .

The miners were faced then by the explosions and the fire, by which suddenly, they were themselves defeated. The first explosion of which there are news happened in 1705, and three years later, another explosion ocurred at a cost of 69 lives. The increase of depth complicated in addition the problem of the ventilation, because below 5 meters of depth , where the atmospheric changes of temperature do not produce effect, there is an increase of one degree of temperature by each 30 meters approximately.

Due to the increase of gases, the illumination difficulties were accentuated while the works were executed, and the greater depths of wells and the extension of the zone in which they were operated made imperative the change of method to carry the coal from the bottom of the well and to elevate this coal until the mouth of the mine . All these difficulties appeared suddenly to the directors of the mines as soon as the layers of soft coal were excavated towards the warm darknesses of the depths of the Earth.

While the mines did not surpass a considerable depth, that is to say, less deep than many of present wells, gases were available of course, although in small amounts, and it became custom burning them before the miners entered to their works. With this object, a worker dressed in a resistant to fire and soaked in water clothes, crawled towards the site where the gases could be accumulated and caused the explosion of them by means of an ignited lamp, placed in the end of a stick . The worker immediately fled from the place, while the flames of ignited gases passed over him licking the ceiling. But this could not last for a long time, and the modification that followed was to try to give exit to the gas, wherever there was a great escape of this one, and by means of a pipe to make it leave to the surface. This was an invention of Carlisle Spedding. His son took an even greater step in favour of the security of the miners modifying the ventilation system, for which two wells were practiced for each mine, so that the air descended by one and ascended by the other, passing by all the workers region , and tending this way to drag with itself all gases, instead of being directed the airflow only towards the sector of the mine where the workers were working.

Photo Jeffrey Manufacturing Co: Train of coal delivery trucks leaving a mine in the direction of the breakers. The continuous world coal demand eventually lead of the invention of the railroads.

The demand of coal lead to the invention of the railroads .
The demand of coal continued increasing enormously, of such a way, that the work sectors that during a long time had not passed more than 200 meters around the bottom of the well, progressively extended and , at the same time, deepened towards lower deposits, creating the necessity to accelerate the coal drag through the mine until the bottom of the well, and to make the elevation of this coal until the mouth more effective and fast. The difficulty of the drag lead to the invention of the tracks, that is arranging strong wood strips throughout the main heavy tunnels of the mine on which wagon with wheels, dragged by horses could circulate. These routes, with wood tracks, also were used to carry the coal, in the north of the United Kingdom , from the mouths from the mines to the fluvial or marine embarkation points for the transport to greater distances. The elevation of the coal until the entrance of the well was first carried out by means of horses to made a capstan work. When the steam was used with this object, it was employed in an indirect way. The machine of Newcomen or the modification of it that James Watt did was used to extract the water of the mine, and this water was used to make work a mill which elevated the coal, procedure that was left by the improvements introduced by Watt in the steam engine, causing that this one was directly usable for the elevation of the coal and all class of loads until the mouth of the mine .

The flexibility impelled to the extraction of the coal increased enormously. At first wicker baskets were used, suspended throughout the well by means of hemp cords, and the it was considered as an extraordinary thing that 90 tons of coal could be raised in a day in one of the mines of Newcastle . Three hundred tons a day was the greatest amount reached by this primitive system of elevation. But , later, with the innovations , thousands of tons could be loaded daily with the powerful steam or electrical elevators working them some times, automatically.

How the coal was extracted from the well in the first times
The first great impulse given to the fast extraction of the coal of a mine was given by John Curr, of Sheffield, who replaced the wood tracks by strained iron tracks , changing delivery trucks with wheels by the old coffers and baskets, using in addition vertical wires throughout the well, which served as guides for a box or strong cage, that would raise and lower throughout the well, and a flat and strong cord that increased the diameter of the cylinder or axis around which the cord was coiled as the suspended box or cage approximated to the mouth of well, accelerating this way the speed of the ascent. This same inventor was the first who used fixed machines for the drag the coal delivery trucks inside the mines. It can be said that the improvements introduced by Curr in the last quarter of XVIII century, and the improvements introduced later by Hall, an English engineer, in the first quarter of XIX century, constituted in general terms the system in use during the beginnings of the XX century to elevate the coal from the bottom of the mine, although, as it is natural, several modifications took place later to facilitate the work in all the phases of the coal mining.

As these measures were taken to obtain the flexibility and economy of the mines , the fight for the life in the every time deeper and deeper wells of the mines, also followed without stopping . Diluting the gases given off by means of a strong current of ventilation or setting fire to the small gas accumulations, turned out to be evidently insufficient to prevent terrible catastrophes.

At the same time, the light produced by the series of sparks obtained with a steel device and a flint , that was sufficient to work in sites where the lamps had caused the gas inflammation and that had been considered as a nondangerous means in the not so deep mines, was fatal when the circumstances changed and it was operated in deeper mines. At the beginning of the XIX century, seven terrible explosions happened in nine months, and the public discussions with respect to the systems of ventilation of the mines became very enthusiastic.

It is clear that the dilution of given off gases using a fresh airflow was not the suitable solution , because the gases were accumulated constantly until they set fire, when they passed near the furnace, located at the exit of the well. Great improvements were made in the ventilation, particularly by John Buddle, of the mines of Wallsend, in Newcastle, who introduced the compound system using two fresh airflows instead of a single one and limiting the circuit of each current.

How Sir Humphrey Davy provided to the world of the Coal's miners Davy safety lamp .
In spite of all these precautions, the catastrophes continued, and it became evident the need to look for the remedy to avoid the ignition of gases, since these could not be entirely eliminated. Under these circumstances the advice of Sir Humphrey Davy was requested , who made a visit to the north of England, where all facts and circumstances were reported to him by Mr. Buddle, the most competent director of mines in those times. "I believe that I can do something for you", were the modest words whereupon Sir Humphrey Davy finished the interview, and seven weeks later, he announced that his experiments and tests had been still more lucky than hoped . The result was the discovery of the coal miner's Davy safety lamp . "Finally we have defeated the monster", was the exclamación of Mr. Buddle, when he saw the lamp burning surrounded by inflammable gases and the lamp that continued burning without inflaming them. Later, when it was asked to Sir Humphrey Davy why he had not get a patent for his invention, he replied "I never thought about such a thing. My object has been to serve the Humanity ". This was the noble final of a great crusade , and it is at the same time a good example of the humanitarian results of many of the investigations of that man of science.

The lamp that has saved thousands and thousands of lives
The lamp of Davy is founded on the supposition of which an explosion does not propagate through small openings, because of the great cooling that experience the gases when crossing trough metallic networks, and in agreement with this theory, he constructed a lamp with a screen.
This invention has been the means to avoid many dangers in the mines, and the cases of apparent failure often were due to the great ignorance or to the involuntary negligence of the lamp operator , but it has been verified that the immunity depends on the speed at which the current of harmful atmosphere crosses the network. Dispositions have been tried to avoid the impulse of the air, and some other improvements have been made in the lamp, but it owes to Davy the merit of the original invention of this great defense that has avoided the loss of many thousands of lives of workers of the mines.
The work of the miner has been and will always be a hard fight against the danger. The death is constantly on his side. He can be poisoned by carbon monoxide , carbonic acid , or carbonaceous hydrogen called marsh gas , or by the products that infest a mine after the explosion; he can be squashed by the collapses of the ceilings and walls of the mines, because always the weight of the undermined Earth tends to sink whatever is on the head of the miner, and to obstruct the underground galleries by pressures in all directions .

In fact, all the work of the miner at the heart of the mine is carried out in the middle of forces that, whether he is alert or not, they can take him by surprise and produce severe injuries . Most of the lost of lives are a consequence of the collapse of the ceilings and walls, coming after the explosions. But science works continuously to eliminate the dangers of the extraction of coal. It had been believed firstly that the only cause of the explosions was the carbureted hydrogen ,called marsh gas, formed by the decomposition of organic matter and the most common gas found in coal mines , not having consequently paid attention to the dust of the coal. In the course of time, nevertheless, the suspicion arose that certain mysterious disasters could indeed have to do with this coal dust, and science began to work to explain the question. Many experiments were done in the 1930's, specially by the Department of Mines of the United States. This institution constructed in those times a great camera in which coal dust clouds could be injected and produce electrical sparks by means of electrical poles. It was found that this way these dust atmospheres could without any doubt produce explosion, and immediately were taken measures to prevent accidents due to this cause. The coal dust was cushioned with water of the mine or it was deposited, covering it with rock dust, and this way it has been possible to save a great number of lives.

Los viejos tiempos - The old times | History of the locomotive .

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