Mining tunnel

“ When we have to use drainage tunnels for our mines we carry the water off from the mouth of the tunnel in a flume, placing quicksilver in the riffles, and if it is a copper mine we place scrap iron in the water and we also use the water for power to assist us in mining, so that at the present time we extract and reduce ore at a lower rate than in other parts of the world, for there is no wastefill management and no overproduction, for in all our mining operations we work those that cost the least, and we operate our coal mines in the same way. ”

“ As the pioneer has to rely upon his right arm for hoisting and drainage, the tunnel offers great temptations, even when it is long and gains but little depth. At a more advanced stage of development, the saving of capital outlay on hoisting and pumping equipment, at a time when capital is costly to secure, is often sufficient justification for a tunnel entry. But at the stage where the future working of ore below a tunnel-level must be contemplated, other factors enter. ”

“ The owner of a tunnel never receives a patent for it. There is no provision in the statute for one, and none is in fact ever issued. No discovery of mineral is essential to create a tunnel right or to maintain possession of it. A tunnel is only a means of exploration. As the surface is free and open to exploration, so is the subsurface. The citizen needs no permit to explore on the surface of government land for mineral. Neither does he have to get one for exploration beneath the surface for like purpose. ”

“ It was the miner who developed the methods introduced by the early civilizations to break rock away from the primary mass, and who added the refinements of subterranean surveying and ventilating, all of which were later to be assimilated into the new art of driving tunnels of large diameter. The connection is the more evident from the fact that tunnelmen are still known as miners.
COPPER MINING, B.C.
Therefore, the first model of the sequence, reflecting elemental rock-breaking techniques, depicts a hard-rock copper mine (fig. 1) . ”

“ An adit or mining tunnel is a horizontal opening driven from the surface. If it be driven along an ore body, as a vein, it is properly called a vein adit; if it is driven across barren country to intercept presumed [96] or known bodies, it is spoken of as a crosscut adit. All adits must be given a small amount of grade for drainage necessities.
Before getting underground we should consider what is required in the way of opening our mine; what is positively known about our body of coal or ore; and what conditions are liable to confront us later on. We must consider the type of ore body ”

“ Again, it is a simpler and cheaper matter to maintain a mining tunnel in working shape than it is a shaft, particularly in bad ground. By the settling or "working" of the ground, a shaft may be thrown perhaps but slightly out of alignment and annoying interferences will be experienced in hoisting, especially when rapid and uninterrupted hoisting is necessary to maintain the desired output. While the same amount of disturbance does take place in an adit, it is an easy matter to readjust track grades while continuing regular haulage operations. ”

“ It was evident, {61} then, that if the project of a tunnel through the Alps was ever to be realized, some extraordinary and completely new system of mining must be adopted, by means of which not only a rapid and perfect system of ventilation could be insured, enabling the miners to resume, without danger, their labors immediately after an explosion, but which would treble, or at least double, the amount of work usually performed in any given time by the system hitherto adopted in tunnelling through hard rock. ”

“ As for the Channel-tunnel shaft itself, it was abandoned in 1902 and filled up with breeze—ashes and slag—from the colliery, and the Number Three ventilation shaft at the eastern end of Shakespeare Cliff was also filled with breeze in the same year. But the colliery never paid off any better than the tunnel project. It ran into trouble around 1907 or 1908, and then the owners decided they'd have a try [118] at getting iron ore out of the workings, and so all the mineral mining rights were bought by the Channel Steel Company, but the iron mining didn't prosper any more than the coal mining. ”

“ However, the day for large figures is approaching; the Sutro Tunnel is to plow through the Comstock lode from end to end, at a depth of two thousand feet, and then mining will be easy and comparatively inexpensive; and the momentous matters of drainage, and hoisting and hauling of ore will cease to be burdensome. This vast work will absorb many years, and millions of dollars, in its completion; but it will early yield money, for that desirable epoch will begin as soon as it strikes the first end of the vein. The tunnel will be some eight miles long, and will develop astonishing riches. ”

“ It would have been a good thing if, when the Low-level Tunnel was open, some lateral prospecting had been done from it to determine the point. An amalgamation of the Venus and Low-level Companies had been arranged with this end in view, but when the privileges held by them passed to the Consolidated Goldfields that company was intent only on pushing the tunnel in to the Golden Fleece shoot, and did not trouble about any other work, and it is questionable if the great cost of reopening the tunnel now for the purpose would be warranted. ”

“ A tunnel is not a mining claim, although it has sometimes been inaccurately called one. As we have seen, it is only a means of exploration. The owner has a right to run it in the hope of finding a mineral vein. When one is found he is called upon to make a location of the ground containing that vein, and thus creates a mining claim, the protection of which may require adverse proceedings. As the claimant of the tunnel he takes no ground for which he is called upon to pay, and is entitled to no patent. ”

“ The cost of cutting a tunnel varies from two to forty dollars a longitudinal foot, according to the nature of the ground, the cost of getting timbers, &c. Tunnels are usually made by companies of eight or ten men, of whom one-half may be merchants, lawyers, physicians or office-holders, and the remainder laboring miners. The latter class do the work; the former furnish provisions and tools, and a certain amount of cash weekly until the pay-dirt is reached. Two or three men work at a time cutting a tunnel; one or two to dig the earth, and one or two to haul it out. ”

“ If the ground at the top of the heading or tunnel Progress of the work—1881. is loose, especially if it is full of water, a different system must be followed to secure the top.
Before mining to place a head-tree, or a crown-bar, polling-boards must be driven by mauls as piles; and where the ground is wet, this is one of the most difficult operations miners have to perform, for the dirty water streams over the end of the piles, and at every blow of the maul is spattered on all the men that are near. ”

“ In many mining regions long tunnels have been driven at great expense to secure natural drainage. Under modern mining conditions drainage tunnels have lost much of their former importance. Taking into account the risk attending all mining operations, which make necessary large interest and amortization charges on the cost of a tunnel, it will in most cases be advisable to raise the water to the surface by mechanical means. Drainage channels are provided, usually along the main haulage roads, by which the water flows to a sump excavated at the pump shaft. ”

“ Thomé de Gamond planned to raise the Varne above water level, thus converting it into an artificial island, by building it up with rocks and earth brought to the spot in ships. Through this earth, engineers would dig a great shaft down [20] to the level of the tunnel, so that the horizontal mining of the tunnel as a whole could be carried on from four working faces simultaneously, instead of only two. ”

“ In underground work the cheapest and easiest method, if the topography and the position of the material to be mined permit, is to approach the ore by tunnels. This may be done where the ore body lies in the side of a hill or mountain, so that it may be approached from the side. If the ore can be taken out through a tunnel, it saves the expense of hoisting it tip through a shaft. The tunnel often also saves the expense of pumping out the water, which often is a troublesome factor in mining. In many cases, however, it is necessary to approach the ore by a shaft. ”

“ Objection to this use of the word rests in the strict definition of a tunnel, which states that it must have both ends open to the natural surface of the earth, as for example, an irrigation or a railroad tunnel. A level passageway which has but one end open to daylight is not properly spoken of as a tunnel. In mining practice, practically every horizontal opening of this nature is open at only one end, and it is an adit rather than a tunnel. ”

“ The draining the deep shaft in the centre of the hill, and the ventilation of the tunnel, having been some time since provided for.
It does not often happen that the processes of the miner lead to so much geological discovery as might be expected; the works he undertakes follow the course of the vein he is exploring, or are confined within a small space bordering upon it. As the veins are sought after in but very few varieties of rock, so the number that are laid open to view is generally limited compared with those that exist in mining districts. ”

“ Where a tunnel is run for the development of a vein or lode, or for the discovery of mines, the owners of such tunnel shall have the right of possession of all veins or lodes within three thousand feet from the face of such tunnel on the line thereof, not previously known to exist, discovered in such tunnel, to the same extent as if discovered from the surface ”

“ The mining upon the hillside claims bears no resemblance in appearance to ordinary placer mining. Horizontal tunnels are driven into the White Channel from the face of the hill, and shafts are sunk into it from the surface in a manner that more nearly resembles the working in ordinary metalliferous lodes. In one such mine which I visited, a horizontal tunnel 700 feet in length had been driven into the gravel, and at right angles to this, and at intervals of about 60 feet, lateral tunnels were being driven to a distance of 70 feet on either side ”

“ But if several tunnels of this kind are driven through one mining area which is yielding metals, and all drain it and supply it with ventilation, then of the metal which is dug out from above the bottom of each tunnel, one-ninth is given to the owner of that tunnel ”

“ Thus he would stop me before I had had time to harm him, and since he need only tunnel just far enough to render the necessary explosion harmless to his house, while I to succeed would have to tunnel right across the road, the man who is counter-mining always has a slight natural advantage over the man who is doing the mining. If only he gets to know what is going on in time he can always retaliate.
All forms of land mine are improvised on the spot according to circumstances. ”

“ The guiding precept of the exhibit has not been to outline exhaustively the entire history of tunneling, but rather to show the fundamental advances which have occurred between primitive man’s first systematic use of fire for excavating rock in mining, and the use in combination of compressed air, iron lining, and a movable shield in a subaqueous tunnel at the end of the 19th century. ”

“ From the earliest periods of rock working, the quest for minerals and metals was the primary force that drove men underground. It was the technology of mining, the product of slow evolution over the centuries, that became the technology of the early tunnel, with no significant modification except in size of workings. ”

“ One man is employed constantly working with a shovel to keep the dirt on the riddle under the stream of water, and in throwing off the big stones. If the pay-dirt is very convenient, two men can shovel enough to keep the machine in operation. The Burke rocker was extensively used in California eight and ten years ago, but now it is a great rarity.
Tunnel-Mining.—A tunnel, in California mining, is an adit or drift entering a hill-side, or running out from a shaft. ”

“ At the present day the word is sometimes popularly applied to an underground passage constructed by trenching down from the surface to build the arching and then refilling with the top soil; but a passage so con structed, although indistinguishable from a tunnel when completed, is more correctly termed a "covered way," and the operations "cutting and covering," instead of tunnel ling. Making a small tunnel, afterwards to be converted into a larger one, is called "driving a heading," and in mining operations small tunnels are termed "galleries," "driftways," and "adits." ”

“ Dynamite alone has doubled the amount of ore which can be extracted from a face in a given time. Le Neve Foster, in his work on mining, gives the rate of advance in driving a tunnel by fire setting at two fathoms per month. Compare with this the Niagara Falls tunnel, driven with power drills and high explosives, 342 feet in four weeks.
It is probably to the power drill more than to anything else that we are indebted for the development of the air compressor; the exhaust from a steam drill and the heat emitted from the pipes being very disagreeable under ground. ”