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Buy the "Great Projects" videos and companion book at ShopPBS. |
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A Challenging Channel Perhaps the most difficult engineering challenge emerged at the Fort Point Channel (near the site of the Boston Tea Party), a narrow waterway where engineers planned a massive, underground interchange for I-90 and I-93. A mammoth casting basin was dug at the edge of South Boston. It was 1,000 feet long, 300 feet wide, and 60 feet deep, big enough to hold three Titanics. Six giant rectangular sections of the tunnel were cast, floated out into the channel, then submerged and sealed. Just one-tenth of a mile long, the Fort Point Channel crossing cost $1.5 billion, the most expensive highway per mile in the world. |
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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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