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Buy the "Great Projects" videos and companion book at ShopPBS. |
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4.4 Million Cubic Yards of Concrete A web of cableways was strung high above the canyon floor, where concrete was poured from large containers. Water from the river was diverted into a web of pipes to cool the blocks of concrete. If the dam had been built as a single monolithic mass, it would not have fully cooled for more than a century. |
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  How engineers contained and controlled the Colorado and Mississippi rivers. Thomas Edison lights up New York City; Sam Insull brings power to Chicago; and TVA electrifies rural America Constructing the George Washington Bridge Putting a major highway under Boston  |
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