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Show (GREAT TUNNEL I DRAINS MINES jWhat Seemed a Hopeless Drainage Problem Completely Com-pletely Solved. Several Rich Veins Cut by Adit Eight Feet Square and Five Miles Long. Driven for a distance on nearly tlvo miles under the center of the Cripple Creok mining district of Colorado, the Roosevelt drainage tunnel has unwatcrcd oro bodies lying deeper than the deepest workings In the district, and has furnished a permanent solution for what once seemed a hopeless drainage problem. More than ton years ago, owing to the enormous quantities of water encountered, the limit of development In the deepest shafts had apparently been reached. At that time several expensive attempts were made to inn... tha MM,,. lo.-M hv nil inni lie. After all attempts to unwatcr the district by this method had failed, work was begun on the Roosevelt tunnel. The tunnel Is now complete, and with Its completion liew life has been put into one of the greatest gold camps In the world. Although designed to solve the drainage problem, tho enterprise carried with It the romance of all such operations In the west. It was possible thai any shot might uncover ore deposits of enormous wealth and this, In fact, was what happened. Numerous valuable finds were made, tho most Important being a vein of rich ore. thirty feet wide, under Battle mountain. Another vein, intersected near Raven hlli. exceeds In value anything that has been found at higher levels. In fact, so Important Impor-tant are the ore bodies discovered that there Is now no question thai the tunnel has created a new Cripple Creek at new low levels. Trench Furnishes Drainage. The tunnel averages from o.ghi to ten feet In width and seven feet high, and is 24.255 feet long. Along one side Is a trench, three leel deep, designed to take care of the drainage after the llrst un-waterlng un-waterlng Is completed. The portai Is in Cripple Creek gulah, five miles southwest of the town of Cripple Creek, and 01 an I elevation of one and a half miles above j sea level. The upper end. .or "face," of the tunnel is under Battle mountain, a mile north of Victor. Throughout Its length t)ie tunnel has a fall of three feet in 1000 feet. It has several Important branches and is connected by "raises" with four of the principal shafts, the Paso, Elkton. Cresson and Portland. One branch connects with the Cresson shaft 2000 feet below the surface, while another. 2000 feet long, connects with one of thc Portland shafts half a m.lt below the surfar-e. If found necessary the tunnel may later bo extended to the Golden cycle shaft. An Idea of the work done by the tunnel Is given by the dniiv records of water discharged dis-charged from the portal. The maximum discharge occurred In ISIS, when for three months tho flow averaged 17.000 gallons per minute. By the end of lslS this had declined to 2.r.0u gallons per minute, indicating indi-cating that the mass of the water had been drained from the district. Calculations Calcula-tions based on these records show that about 40.000.000,000 gallons of water has been discharged througli the tunnel since the beginning of the construction work. Tunnel Started Years Ago. I'lane for the big drainage project were laid as eorlv as 1S06, and construction actnallv started In ISO; but even at that time the El I'aso dram was already In existence, having been completed In 1003. The function of this earder ban was to unwater the westerll portion of the field. Tho El I'aso tunnel, however, operated only to the sxO-foot level, and soon proved inadequate, though it greatly Increased values at the time. The new work Just completed cost practically $1,000,000. and thc drainage problem has been solved once for all Mining operations as deep as the tunnel will never again be seriously hampered by water. Shafts sunk deeper than this will no doubt encounter water In largo quantities, but this will have to be pumped only to the tunnel level, an Inconsiderable task compared with tlie additional lift of I sheer half mil that wouid be necessary If only surfnee drainage drain-age was available. Popular Mechanics. |