Why Hoover Dam Needed an Ice Factory

In the 1930s, engineers building Hoover Dam faced a problem nobody could see: the concrete was cooking itself from the inside. Poured as one solid mass, the dam would have taken more than a century to cool, and it would have cracked long before. This is how they solved it: a river moved into four tunnels, high scalers hanging from ropes, a dam split into hundreds of columns poured five feet at a time, more than 580 miles of cooling pipe, a refrigeration plant that could make a thousand tons of ice a day, and the grout that sealed it all back into one wall. And why, ninety years later, it is still standing. 00:00 The ice was for the wall 00:37 Why this dam should not exist 01:34 A river that did what it wanted 04:15 Moving the Colorado 07:28 The hidden heat 11:25 The shape that holds the lake 13:49 The price 14:32 Why it is still standing Sources: U.S. Bureau of Reclamation, "Hoover Dam FAQs" and "The Story of Hoover Dam" essays (concrete; high scalers). National Park Service, "The Greatest Dam in the World: Building Hoover Dam" (Teaching with Historic Places). American Society of Civil Engineers, Hoover Dam Historic Civil Engineering Landmark. Music (YouTube Audio Library): "At the Precipice of a Dying Light" by Dan Bodan "Final Girl" by Jeremy Blake "Your Suggestions" by Unicorn Heads