Incredible Images Tell The Story Of The Construction Of The Hoover Dam

Starting around the turn of the 20th century, the Black Canyon and nearby Boulder Canyon in Arizona and Nevada had been investigated for their potential to control flooding, provide irrigation water, and produce hydroelectric power to help support rapid development within the southwestern United States.

In 1922, the U.S. Reclamation Service settled on Black Canyon as the ideal location for a dam. In 1929 the project was authorized by Congress.  The winning bid to build the dam was submitted by a consortium called Six Companies, Inc., which began construction on the dam in early 1931.

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An inspection party near the proposed site of the Hoover Dam (aka Boulder Dam) in the Black Canyon of the Colorado River, circa 1928. (Photo by Keystone/FPG/Hulton Archive/Getty Images)

An inspection party near the proposed site of the Hoover Dam (aka Boulder Dam) in the Black Canyon of the Colorado River, circa 1928. (Photo by Keystone/FPG/Hulton Archive/Getty Images)

 

Construction began in 1931 with the Great Depression in full swing.  Tens of thousands of flocked to the site with their families, hopeful for work.  Many found it; at its peak, the project employed 5,251 people.

ca. 1931-1936, Boulder City, Nevada, USA --- A surveyor waves his cowboy hat as a signal to fellow workers at Boulder Dam. Now called Hoover Dam, it is one of the world's largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. --- Image by © CORBIS

ca. 1931-1936, Boulder City, Nevada, USA — A surveyor waves his cowboy hat as a signal to fellow workers at Boulder Dam. Now called Hoover Dam, it is one of the world’s largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. — Image by © CORBIS

12 May 1933, USA --- Original caption: Near Las Vegas: 4-Ton Dynamite Blast Set Off At Hoover Dam Site. A mountain of dirt and rock rises skyward after a four ton dynamite blast was set off, marking the last "big shot" before construction of Hoover Dam proper begins near Las Vegas, Nevada. The explosives were detonated from 3,000 drill holes honeycombing the section of earth to be moved, a rock ledge on the lower canyon walls selected as the site for power houses. The roar of the explosion echoed through the walls of Black Canyon for 15 minutes. --- Image by © Bettmann/CORBIS

12 May 1933, USA — Original caption: Near Las Vegas: 4-Ton Dynamite Blast Set Off At Hoover Dam Site. A mountain of dirt and rock rises skyward after a four ton dynamite blast was set off, marking the last “big shot” before construction of Hoover Dam proper begins near Las Vegas, Nevada. The explosives were detonated from 3,000 drill holes honeycombing the section of earth to be moved, a rock ledge on the lower canyon walls selected as the site for power houses. The roar of the explosion echoed through the walls of Black Canyon for 15 minutes. — Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA --- Original caption: 1933-Boulder City, CO- Picture shows a view of a bridge crossing at the Boulder Dam (known now as the Hoover Dam). --- Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA — Original caption: 1933-Boulder City, CO- Picture shows a view of a bridge crossing at the Boulder Dam (known now as the Hoover Dam). — Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA --- Original caption: 1933-Boulder City, CO- Picture shows dump trucks driving along the side of a mountain where men on working on construcing the Boulder Dam (known now as thew Hoover Dam). --- Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA — Original caption: 1933-Boulder City, CO- Picture shows dump trucks driving along the side of a mountain where men on working on construcing the Boulder Dam (known now as thew Hoover Dam). — Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA --- Original caption: 1933-Boulder City, CO- Picture shows an aerial view of mass construction of the Boulder Dam (known now as the Hoover Dam). --- Image by © Bettmann/CORBIS

1933, Boulder City, Nevada, USA — Original caption: 1933-Boulder City, CO- Picture shows an aerial view of mass construction of the Boulder Dam (known now as the Hoover Dam). — Image by © Bettmann/CORBIS

ca. 1935, Boulder City, Nevada, USA --- Shaving the walls of Black Canyon, 550 feet above the mighty Boulder Dam. --- Image by © Bettmann/Corbis

ca. 1935, Boulder City, Nevada, USA — Shaving the walls of Black Canyon, 550 feet above the mighty Boulder Dam. — Image by © Bettmann/Corbis

 

After redirecting the river using 3 miles of diversion tunnels, excavation began to remove loose sediment and rocks from the river bed and canyon walls. The arch-gravity dam was designed to transfer the force of the water to the walls, so they needed to be attached directly to bedrock.

To accomplish this, workers known as “high scalers” would rappel down the walls and hammer away anything that was loose. Falling rock and debris was a serious hazard, so the workers dipped their hats in tar and let them dry and harden — the first hard hats.

1934 --- Contruction workers rappel down cliff face dw-1934-12-08-70~09 --- Image by © Dick Whittington Studio/Corbis

1934 — Contruction workers rappel down cliff face dw-1934-12-08-70~09 — Image by © Dick Whittington Studio/Corbis

In June 1933, the pouring of concrete began. But engineers had a problem to overcome – the chemical reactions which occur during the hardening of concrete generate high levels of heat. It was estimated that if the entire dam was poured as a single concrete block, it would take 125 years to cool.

11 Sep 1933, Boulder, Colorado, USA --- Original caption: Progress of Boulder Dam construction. Striking scenes of the progress of the construction work on Boulder Dam. This photo shows the concrete and steel foundation of the dam. --- Image by © Bettmann/CORBIS

11 Sep 1933, Boulder, Colorado, USA — Original caption: Progress of Boulder Dam construction. Striking scenes of the progress of the construction work on Boulder Dam. This photo shows the concrete and steel foundation of the dam. — Image by © Bettmann/CORBIS

 

To work around this problem, they used what they called “lifts”.  These were rectangular blocks that could be filled with concrete and then cooled by pipes filled with ice-cold water.  By the time that pouring had completed in May 1935, enough concrete had been used to pave a highway from New York to San Francisco.

circa 1936:  The Boulder Dam on the Colorado River under construction. A cable railway runs over it.  (Photo by General Photographic Agency/Getty Images)

circa 1936: The Boulder Dam on the Colorado River under construction. A cable railway runs over it. (Photo by General Photographic Agency/Getty Images)

 

While the story that there are bodies entombed in the dam of workers that died during construction is only a myth, the construction was very dangerous.  There were officially 112 deaths as a result of the project.  The first was J.G. Tierney, a surveyor who drowned while searching for a spot for the dam on December 20, 1922.  Incredibly, the last worker to die, 13 years later to the day, was Tierney’s son, Patrick.

1934 --- Concrete conveyance dw-1934-412-08-67~37 --- Image by © Dick Whittington Studio/Corbis

1934 — Concrete conveyance dw-1934-412-08-67~37 — Image by © Dick Whittington Studio/Corbis

1934 --- Concrete being dumper from conveyer dw-1934-412-08-67~35 --- Image by © Dick Whittington Studio/Corbis

1934 — Concrete being dumper from conveyer dw-1934-412-08-67~35 — Image by © Dick Whittington Studio/Corbis

19 Sep 1933, Boulder, Colorado, USA --- Original caption: At Boulder Dam. Mayor Frank L. Shaw of Los Angeles and a party of newspapermen returned recently from a three day inspection tour of Boulder Dam and construction camps along the route of the city's $22,800,000 electric transmission line. The line will extend from Los Angeles to the Boulder Dam power plant on the Colorado River. This photo shows a close up view of the dam construction. --- Image by © Bettmann/CORBIS

19 Sep 1933, Boulder, Colorado, USA — Original caption: At Boulder Dam. Mayor Frank L. Shaw of Los Angeles and a party of newspapermen returned recently from a three day inspection tour of Boulder Dam and construction camps along the route of the city’s $22,800,000 electric transmission line. The line will extend from Los Angeles to the Boulder Dam power plant on the Colorado River. This photo shows a close up view of the dam construction. — Image by © Bettmann/CORBIS

1934, Boulder City, Nevada, USA --- Construction continues atop Boulder Dam. Now called Hoover Dam, it is one of the world's largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. --- Image by © CORBIS

1934, Boulder City, Nevada, USA — Construction continues atop Boulder Dam. Now called Hoover Dam, it is one of the world’s largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. — Image by © CORBIS

ca. 1931-1936, Boulder City, Nevada, USA --- Massive steel bar columns rise in the construction of Boulder Dam. There is as much steel in the dam as is in the Empire State Building and enough concrete to lay a highway from California to Florida. Now called Hoover Dam, it is one of the world's largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. --- Image by © CORBIS

ca. 1931-1936, Boulder City, Nevada, USA — Massive steel bar columns rise in the construction of Boulder Dam. There is as much steel in the dam as is in the Empire State Building and enough concrete to lay a highway from California to Florida. Now called Hoover Dam, it is one of the world’s largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. — Image by © CORBIS

1934 --- dw-1934-412-08-67~06 --- Image by © Dick Whittington Studio/Corbis

1934 — dw-1934-412-08-67~06 — Image by © Dick Whittington Studio/Corbis

1934 --- Two men looking at huge pipes for the Hoover Dam dw-1934-412-08-67~08 --- Image by © Dick Whittington Studio/Corbis

1934 — Two men looking at huge pipes for the Hoover Dam dw-1934-412-08-67~08 — Image by © Dick Whittington Studio/Corbis

ca. 1931-1936, Boulder City, Nevada, USA --- Workers build a massive tunnel as part of Boulder Dam. There is as much steel in the dam as is in the Empire State Building and enough concrete to lay a highway from California to Florida. Now called Hoover Dam, it is one of the world's largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. --- Image by © CORBIS

ca. 1931-1936, Boulder City, Nevada, USA — Workers build a massive tunnel as part of Boulder Dam. There is as much steel in the dam as is in the Empire State Building and enough concrete to lay a highway from California to Florida. Now called Hoover Dam, it is one of the world’s largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada. — Image by © CORBIS

1934 --- dw-1934-412-08-67~03 --- Image by © Dick Whittington Studio/Corbis

1934 — dw-1934-412-08-67~03 — Image by © Dick Whittington Studio/Corbis

1934 --- Hoover dam vent towers during construction dw-1934-12-08-70~10 --- Image by © Dick Whittington Studio/Corbis

1934 — Hoover dam vent towers during construction dw-1934-12-08-70~10 — Image by © Dick Whittington Studio/Corbis

30 Jan 1935 --- Original caption: First of the gigantic hydroelectric generators for Boulder dam. The 19 student engineers representing 15 different universities at the Schenectady works of the general electric company, where the 82,500 KVA. unit was built, are shown atop the world's largest". Weighing two million pounds, the generator must be taken apart and shipped to Black Canyonj on 45 freight cars. --- Image by © Bettmann/CORBIS

30 Jan 1935 — Original caption: First of the gigantic hydroelectric generators for Boulder dam. The 19 student engineers representing 15 different universities at the Schenectady works of the general electric company, where the 82,500 KVA. unit was built, are shown atop the world’s largest”. Weighing two million pounds, the generator must be taken apart and shipped to Black Canyonj on 45 freight cars. — Image by © Bettmann/CORBIS

25 Feb 1935, USA --- Floodlights illuminate Boulder Dam at night during construction. Boulder Dam, now called Hoover Dam is one of the world's largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada, USA. --- Image by © CORBIS

25 Feb 1935, USA — Floodlights illuminate Boulder Dam at night during construction. Boulder Dam, now called Hoover Dam is one of the world’s largest dams, holding back the waters of the Colorado River between Arizona and Nevada to create power and Lake Mead. Nevada, USA. — Image by © CORBIS

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October 1935, Boulder, Colorado, USA --- Front View of the Boulder Dam --- Image by © Bettmann/CORBIS

October 1935, Boulder, Colorado, USA — Front View of the Boulder Dam — Image by © Bettmann/CORBIS

1935:  Aerial view of  the construction of the Boulder Dam, renamed the Hoover Dam in 1947, shortly before its completion, Nevada.  (Photo by Hulton Archive/Getty Images)

1935: Aerial view of the construction of the Boulder Dam, renamed the Hoover Dam in 1947, shortly before its completion, Nevada. (Photo by Hulton Archive/Getty Images)

 

On Sept. 30, 1935, President Franklin D. Roosevelt dedicated the dam.  The next year the hydroelectric power plant was turned on, providing electricity to cities in California, Nevada and Arizona.

ca. 1935 --- Original caption: President Roosevelt, high up on one side of the huge Boulder Dam at Boulder City, Nevada, points to one feature of the mighty structure, and asks a question. Walker Young, the engineer in charge of the project conducted the Chief Executive on a tour of the dam, after which Roosevelt made a dedication address, during which he pointed out that federal spending had given the nation useful works such as this one, and had started the wheels of private industry turning. --- Image by © Bettmann/CORBIS

ca. 1935 — Original caption: President Roosevelt, high up on one side of the huge Boulder Dam at Boulder City, Nevada, points to one feature of the mighty structure, and asks a question. Walker Young, the engineer in charge of the project conducted the Chief Executive on a tour of the dam, after which Roosevelt made a dedication address, during which he pointed out that federal spending had given the nation useful works such as this one, and had started the wheels of private industry turning. — Image by © Bettmann/CORBIS

12 Sep 1936, USA --- Original caption: 9/12/1936-Boulder Dam, AZ/NV- An electrical impulse released by President Roosevelt pressing a button across the continent sent 3,600,000 cubic feet of water a minute tumbling through Gigantic Boulder Dam, and put the Colorado River to work generating electrical power. This photo made by Albert Kopec from a Richfield Oil Company plane, shows the Niagara of water from the 12 outlets; six on the Nevada side and six on the Arizona side. --- Image by © Bettmann/CORBIS

12 Sep 1936, USA — Original caption: 9/12/1936-Boulder Dam, AZ/NV- An electrical impulse released by President Roosevelt pressing a button across the continent sent 3,600,000 cubic feet of water a minute tumbling through Gigantic Boulder Dam, and put the Colorado River to work generating electrical power. This photo made by Albert Kopec from a Richfield Oil Company plane, shows the Niagara of water from the 12 outlets; six on the Nevada side and six on the Arizona side. — Image by © Bettmann/CORBIS

1940, Arizona, USA --- Men take in the view of the Boulder Dam and Lake Mead from the Nevada side of the Colorado River. | Location: Border of Arizona and Colorado, USA. --- Image by © Schenectady Museum; Hall of Electrical History Foundation/CORBIS

1940, Arizona, USA — Men take in the view of the Boulder Dam and Lake Mead from the Nevada side of the Colorado River. | Location: Border of Arizona and Colorado, USA. — Image by © Schenectady Museum; Hall of Electrical History Foundation/CORBIS

The dam was the largest manmade structure in the world when completed, and Lake Mead was created, the largest reservoir in the United States.  It had been built using techniques that were unproven at the time.  High temperatures and lack of facilities near the site also presented difficulties.   Nevertheless, Six Companies turned over the dam to the federal government on March 1, 1936, more than two years ahead of schedule.

Sources: mashable, wikipedia