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The largest power canal in the world is at Sault Ste. Marie, Michigan, and is used for the operation of gigantic iron industries. It provides for the reduction of 20,000,000 tons of iron ore at the very door of the, mines. In the water power development at the "Soo" is realized the utilization of the natural force inherent in the waters of Lake Superior. There they flow out over a sandstone ledge about a half mile long, half a mile wide, with a fall of 20 feet. Lake Superior covers an area of about 36,000 square miles and is fed from a water-shed many times greater, the Sault Rapids being its only outlet. The quantity of the water discharged fluctuates, with the varying conditions of precipitation and evaporation, from about 3,600,000 to 7,000,000 cubic feet per minute, which, rushing over the Sault Rapids, represents an equivalent of from 130,000 to 260,000 horse power. Just south of the western entrance to the United States Ship Canal lies the intake to the power canal, about 950 feet wide. The total distance of the constructed waterway is about 13,000 feet, the width from the expanded intake entrance gradually lessening to 200 feet, excavated to such a level that, when the full maximum power of the works is being used, water will flow at a uniform depth of 25 feet. The entire construction of the canal has been carried on with a view to the greatest efficiency in delivering the energy of the water, and it is everlasting in durability. Throughout the intake the sides of the canal are retained by timber cribs securely placed and framed, rendering the sides of the waterway smooth and permanent. The timber construction is continued to a point just below the water, and covered with masonry construction. The canal sides through the rock formation are channeled out vertically its walls and bed being smooth. All defects in stratification are remedied by masonry construction, of which the embankments also consist. The flow area of the canal differs with its different sections. The water will flow 25 feet deep through the entire canal, and will attain a velocity of four and a half miles an hour. This will deliver, approximately, 30,000 cubic feet of water every second to the turbines. The conduit terminates at the power house, which performs the function of a dam, in which water wheels are so placed that the only escape for the water to the lower level is through them. The equipment consists of hydraulic and electric apparatus. Each hydraulic unit is composed of four new 33-inch American turbines, arranged in two parts on one shaft. Each pair is housed in one case and discharges into one draught tube. The installation is of the horizontal, tandem type, the shaft and operating rigging penetrating the steel-plate bulkhead and coming out on the dynamo floor side. Each hydraulic unit, under normal conditions, equals 568 horse-power. Involved in the construction of this canal were 1,250,000 cubic yards of rock and 3,000,000 cubic yards of sand excavated and dredged. This material was all utilized in reclaiming land under water, which is the property of the operating company. The material used consisted of 3,500,000 lineal feet of piles, 170,000 tons of concrete and monolithic blocks, 90,000 cubic yards of sandstone masonry, 32,000 square yards of dry sandstone pavement, 260,000 barrels of cement, used in all masonry, and 24,000 square feet of iron roofing. Two hundred and sixty acres of land were reclaimed during the construction, being filled in with the excavated material; 2,800 lineal feet of navigation docks were built; 22 miles of rails were laid and operated. The excavation was carried on with an equipment of eight steam shovels, 24 locomotives and 350 four-yard dump-cars, all work being carried on night and day, excepting Sundays. The approximate cost of the entire right of way, canal, power-house, equipment, docks and appurtenant works, developing 57,000 horse power, is about $4,000,000. THE WORLD'S STUPENDOUS GRANARY |