HISTORY OF DAM BUILDING

     Fort Peck was built in 1937, and it is one of the largest dams, based on volume of dam structure. Fort Peck, built in the U.S., is a 4 mile long earth-fill dam with a volume of 96 million cubic meters! How was this built in the early 1937? Improvements in engineering techniques and building materials have led to such  unbelievable constructions.
    Dams were built using concrete, stone, and other masonary. The complicated structures of the dams were built by earth-moving machinery. The machinery were powered by diesel motors, which are similar to the ones used in trucks. The machinery are used to dig out and partially transport large amounts of bank soil. During the 1900s, improvements in engineering techniques and building materials have led to the construction of higher and longer dams than ever before.

The technology involved:
                   Earth-moving machinery(move and transport stones), cable cars(hauling away earth from foundation), steam-driven pumps(top underground springs and leakage from the river floods), special narrow-gauge, railway steam locomotives with flat cars (puffing back and forth between the quarry and the riverbed-not that this is before trucks became common),and motor crane (raises and positions steel parts of the dam).
    By the early 1900s, there was a great advancement in technology, including portland cement concrete and the mechanization of earth-moving and materials-handling equipment. These developments allowed the "construction of indestructible dams of appreciable height and storage capacity. Earth-moving machines were vital in most civil engineering projects, including the construction of dams. Building a dam almost always required the "moving of millions of cubic meters of earth." Dredges, diesel-fueled tractors, and draglines were some of the most widely used earth-moving machines of the early 1900s.
    Dredges performed "the removal of earth or material from the bottoms of bodies of water." They had very powerful, steam-powered sution equipment. "The hydraulic dredges sucked the soil into the dredge through a pipe, and were commonly fitted with a floating pipeline through which the spoil was discharged on the shore."
   The present-day heavy-duty tractors did not exist in the early 1900s, however, small disel-fueled tractors were in common use. They were the primary source of moving tons and tons of earth. Tractors properly shaped the rough terrain of the area where the dams were to be built. Also, these machines were usually "equipped with a front-end loader, a scoop shovel affixed to the front of the tractor,it can lift and carry gravel, stone, sand, and other construction materials."
    "Draglines and power shovels were the primary forms of excavation equipment. A dragline was fitted with an open scoop supported from the end of a long boom by a wire cable. The scoop was dragged along the ground by the cable until it was filled with earth, which was then dumped elsewhere. Draglines were used primarily to excavate deep holes. Power shovels were fitted with buckets called clamshells, which dug into the earth and shovel it up. The bottom of the clamshell opened to dump the dirt into a truck for removal."

Procedure for building a dam- To illustrate, let's describe the steps involved in the construction of the Hoover Dam.
    1. The engineers initial task is to make a comprehensive plan of building the dam. They chose the right place, right shape, and right kind of foundation for the river bottom. Engineers test the rocks, which are situated around the area where the dam would be built, to make certain that it could support the burden of the enormous weight of concrete.
    2. The engineers must "turn the river off" to divert its flowing while construction was taking place. They dug 4 tunnels, each one 56 feet wide and 4,000 feet long, into the solid rock of the canyon walls. This was done with a 2,300-volt electric Marion shovel that would muck out the tons and tons of materials. The bypass tunnels were very important because they would carry the water away from the construction site.
    3. Then the cofferdam, the temporary restraining wall upstream of the contruction site, was built.
    4.  Finally, the dam itself is constructed using various technology of the time.
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