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Show ffa Cer jJowev of Weld Mde Effects , ;V.,,:,:.. f i .If .': " ; ,fir- 4 '5 - .; Ar$ , I i " " S i i ; ' -j ' - t J . U t . . v v , N - i ; c4z 5LCT10N OF DOWKcSTRLAM SIDL TT N THE heart of the United States, but at a point which is one of the nearest by transportation routes to the countries of Central and South America, is being built a giant water power plant which must greatly affect for good not only ita immediate im-mediate environment, the Mississippi valley, but the whole nation and all the nations in Pan America. The colossal co-lossal size of the water power there would cause appreciable effects anywhere any-where in the world, and it is located almost exactly at the point where its commercial influence may be exerted most easily and effectively upon world commerce. The achievement nearing completion comple-tion is the damming of the mighty Mississippi river, harnessing it to turbine tur-bine wheels and electric generators and distributing its tremendous power over one hundred miles and more of the most efficient portion of the United States on a direct traffic line to the rest of the western hemisphere. It is not only an unparalleled engineering engin-eering achievement, but also perhaps the greatest single economic force flung into the world by the hand of man, excepting only the Panama canal. Nearly Mile Long. The basis of the water power de- velopment at Keokuk, in the southeastern south-eastern corner of the state of Iowa, is a gTeat dam extending for nine-tenths nine-tenths of a mile from the Illinois bluff to its junction with the titanic power pow-er house near the Iowa shore. This dam is a composite structure of 119 arched spans, all alike, with piers six feet thick thirty feet apart, and spillways spill-ways in the spans, all alike, over which the water will flow. This dam is a monolith of massive concrete set down several feet into the hard rock bottom of the Mississippi, but impounding im-pounding the water by it3 immense weight. The structure, with the exterior ex-terior appearance of a bridge, is 63 feet high, 42 feet wide at the bottom, and 29 fe t wide on top; the spillways between the piers are 32 feet high, fill the width of the dam at the bottom, have vertical upstream faces, and thir downstream face is an ogee ;urve which delivers the water at the bottom horizontally to the river current. cur-rent. On top of each spillway will be i steel ate 11 feet high. By varying Lhe number of these gates, which are open and closed, the amount of water flowin:; over the dam will be regulated, regulat-ed, with the result that at varying stage:; of the river the pool above the dam will have always an unvarying depth and its surface will always remain re-main at the same place. The water wheel itself Is another example of overcoming the impossible, impossi-ble, for experts said that it was impossible im-possible to build a turbine which would meet the unusual conditions there. But Chief Engineer Cooper called a council of war and a little later rose from the head of that table with a new design of turbine which tests show has 86 per cent of efficiency effi-ciency as compared with the next best result ever attained of 80 per cent, and a textbook figure of 75 per cent. Df efficiency as the norm to be used In engineering calculations. The 30 turbine wheels in the Keokuk power house are several times as large in dimensions as any ever made before. Bach is at the lower end of a shaft 25 Inches in diameter, on the upper end of which Is the revolving part of the Electric generator standing on the power-house floor. The revolving ihnft with its machines at each end, weighs about 552,000 pounds, and it Is supported on one bearing which is lubricated by forcing oil between its surfaces at a pressure of 250 pounds to the square inch. From this bearing bear-ing a steel cone carries the weight to a huge ring below, and the total weight of one turbine unit is about S82.000 pounds. The lower ring itsell weighs about 111,000 pounds, and between be-tween it and an upper ring of similar size is a steel cylinder embedded in the massive concrete, which is the basement of the power house. The 30 turbines develop over 300,000 horsepower, horse-power, and this is increased by two auxiliary smaller wheels, which also energize the exciters of the electric generators. This is over three times as much power as is developed in any one other water-power plant In the world. After deducting slight losses of energy and very large reserve, 200,000 horsepower will be sold for commercial use. At the lower end of the great power house is a colossal lock with the same width as those at Panama and with a lift of 40 Teet instead of the lift of 28 feet 4 inches in any one lock at the canal. Beside the lock will be a mammoth mam-moth dry dock for building and repairing re-pairing boats. There is also a long and high wall protecting the tracks of a railroad alongshore, which must be elevated above the new water level above the dam, and an ice fender like a concrete bridge over a kilometer long is anothr part of the work there in the bottom of the Mississippi river, riv-er, built to keep ice and debris of all kinds out of the turbines. At its western end this 'largest of power dams joins the power house, which stretches almost at right angles down the river for almost a third of a mile accurately, 1,718 feet with a width of about 133 feet and a height of over 177 feet. The water from the immense forebay between the power house and the Iowa shore passes through thirty arched portals, behind which are buttressed, on their outer ends, the steel rods acting as strainers. Behind each arched portal por-tal are four Intakes to each turbine water wheel, each Intake being 22 feet high. Work of Many Years. The origin of that water power development de-velopment is most interesting. It is the result of remarkably persistent labor la-bor on the part of the people of that community through several decades. In the middle of the last century the value of the vast quantity of power going to waste there was recognized and various unsuccessful movements to utilize it were launched. Then ten years were Bpent in work which was successful at last. A corporation which really was a trustee for the people peo-ple made preliminary surveys, collected collect-ed data, obtained a franchise act from congress, and searched for capital to build the water power installation, It obtained its funds from the municipal treasuries of Keokuk and of Hamilton, Hamil-ton, 111., across the river. It succeeded succeed-ed only after it interested in the project proj-ect Mr. Hugh L. Cooper, who organized organ-ized the present proprietor company only after much labor and many rebuffs, re-buffs, and succeeded finally chiefly because be-cause of his record of successful building of water power plants at Niagara Ni-agara Falls, Sao Paulo and other places. It is intended to start the turbines and generators in the mammoth power pow-er house early next summer, with the president of the United States pulling the lever to start the turbines, while he stands surrounded by the governors of all the states In the Mississippi valley. |