Constructed between 1931 and 1935, the Hoover Dam stands as an engineering wonder, with few at the time able to foresee the immense challenge of not only building the world’s tallest dam but also ensuring its concrete core would endure over time.

Symbolizing the American resolve during the Great Depression, this colossal structure necessitated a novel method for concrete curing that continues to this day.

The secret to the dam’s durability lies in the concrete curing process. Engineers from the construction period predicted that the concrete would require approximately 100 years to cure fully.

This extended time frame is attributed to the immense size of the dam and the heat produced by the curing concrete.

Had the dam been built with a single concrete pour, the concrete would have become so hot it was estimated to need 125 years to cool to ambient temperatures.

To mitigate this heat and avert structural harm, the Hoover Dam was constructed not as one piece but in a succession of individual trapezoidal columns, a design that allowed for more efficient heat dissipation.

Moreover, a network of cooling coils, consisting of “582 miles of 1-inch steel pipe,” was embedded within the concrete. The system initially circulated river water before chilled water from a refrigeration plant was introduced to expedite the cooling process.

This refrigeration plant was no small feat, having the capacity to “produce 1,000 tons of ice in 24 hours.” This innovative system reduced the cooling duration to a more practical timeframe, although the curing process continues to this day.

The statistics surrounding the construction of Hoover Dam are staggering. The dam contains “4,360,000 cubic yards of concrete,” and if all materials used were loaded onto a train, “as the engine entered the switch yards in Boulder City, the caboose would just be leaving Kansas City, MO.”

Building the dam during the Great Depression was too costly for a single company to manage independently. Therefore, a consortium of construction companies joined forces under the name Six Companies and successfully secured the project with a bid of $48.8 million.

This bid was the largest contract granted by the federal government at that time. Around 21,000 men were employed for the dam’s construction, with an average of 3,500 workers daily. The peak daily workforce exceeded 5,200 laborers in June 1934.

The construction itself was a Herculean task. The “first concrete for the dam was placed on June 6, 1933,” and the “last on May 29, 1935.”

On average, “160,000 cubic yards of concrete were placed in the dam per month,” with peak placements reaching “10,462 cubic yards in one day.”

The Hoover Dam not only tamed the Colorado River but also created Lake Mead, the largest reservoir in the United States.

While the dam’s primary function was flood control, water diversion, and hydroelectric power generation, it also holds a place in America’s architectural history as a structure that surpassed the Great Pyramid of Giza in its masonry mass.