If you were compiling a list of the Top Ten Infrastructure Projects, you would have to include Hoover Dam. Its contribution to our society is immeasurable. Although a high percentage of the direct benefits go to Nevada, California, Arizona and the rest of the Southwest, we have all benefited from it. For social impact Hoover Dam has to be one of the top three on everyone’s list.
Las Vegas always brings to mind thoughts of endless neon lights, stars, shows, food and of course the slot machines and tables. What would Las Vegas be with out “The Strip,” without the glitter, without Hoover Dam, or do you confuse it with Boulder Dam? Hoover Dam, once known as Boulder Dam, holds back the water in a reservoir named Lake Mead, which is one of the most beautiful lakes in North America. It is filled with a great variety of fish as its shoreline is populated with a choice selection of wildlife, including mountain goats.
If you’ve been to Las Vegas and have never taken the time to visit the incredible Hoover Dam and Lake Mead you have really missed out on some spectacular scenery and one of the engineering wonders of the modern world.
You owe it to yourself and your family to take a tour of the dam and see what all it is and does. The Colt .45 may be the gun that won the West, but Hoover Dam is the construction project that changed the Southwest, taking it from a desert wasteland to one of the premier agricultural centers of the country.
And, I’m not even stating the fact that is also produces the electricity that sets “The Strip” aglow at night and cools the casinos, keeping the desert heat outside, where it belongs. If the dam didn’t exist, neither would Las Vegas.
And no, I did not do a story on this project while it was under construction! I wish I could have. I have toured it several times both before and after the updates and improvements. Each visit was as awesome as the first.
Hoover Dam or Boulder Dam? The original site of the dam was to be at Boulder Canyon, about 10 miles upstream from the current location. As a result, it was named “Boulder Canyon Project.” It was decided after the project began that if the dam were built at Black Canyon instead of Boulder Canyon, it would be able to capture more water. Also, geologically, Black Canyon had a more dense rock in its canyon walls, so when the dam site was moved to Black Canyon, it was still called the Boulder Canyon Project.
On September 17, 1930, President Herbert Hoover’s Secretary of the Interior, Ray L. Wilbur, went to the site to dedicate the official start of the project. In his dedication speech, he announced that the dam would from that day on be officially known as Hoover Dam. This was a rather unpopular idea at the time.
In 1930, the Great Depression was getting worse, and Hoover was either blamed for it or castigated for not doing anything about it. Herbert Hoover, wanting to be re-elected in 1932, felt that he needed to show that he was sensitive to the situation. By naming the dam after himself, he thought that he could draw attention to the fact that he was instrumental in starting the project. With over 5000 people to be employed on the project, President Hoover thought that he could claim credit for trying to do something about the unemployment situation, which was extreme at that time. Unfortunately for Hoover, it did not work out that way.
Let’s hope that this is one of the times that history does not repeat itself…
On May 8, 1933, Harold Ickes, President Franklin D. Roosevelt’s Secretary of the Interior, decided that the name of the dam should once again be Boulder Dam. The reason for this was no doubt political. On April 30, 1947, a resolution renaming the dam, Hoover Dam, was passed by congress and signed by President Harry S. Truman. It is still known as Hoover Dam.
Growing up, I heard it referred to as Boulder Dam more often than it was called Hoover Dam. Of course, people suffered from the ravages of the Great Depression for years.
Construction began in 1931, and Hoover Dam was completed in 1935. The completion of the dam drew massive crowds for Dedication Day, September 30, 1935. Franklin D. Roosevelt delivered the address, calling the Hoover Dam “an engineering victory of the first order–another great achievement of American resourcefulness, skill, and determination.”
When completed, it was both the world’s largest electric-power generating station and the world’s largest concrete structure. Power generation began in 1936 and turbines continued to be added until 1961, when the last one went on line. It still stands tall as an engineering marvel high above the Colorado River between Arizona and Nevada. Hoover Dam attracts over 7 million visitors from around the world every year feeding vast tourism into the Las Vegas, Nevada and Arizona economy.
The building of Hoover Dam took the brilliance of over 200 engineers to pull off what many deemed as almost impossible. And it was the fortitude of over 7,000 dam workers that endured amazingly harsh conditions and extreme dangers to complete Hoover Dam almost two years ahead of schedule.
The mission of Hoover Dam was multi-purpose. Flooding along the Colorado River as it made its way to the Gulf of California had to be controlled. The water flow had to be harnessed to provide much needed water to the fertile, yet arid agricultural areas of California and Arizona. And hydroelectric energy was to satisfy the requirements of millions of people in adjacent regions.
A scenic by-product of Hoover Dam is the gigantic reservoir of Lake Mead, a stunningly beautiful water recreation wonderland. This boating, sailing, fishing and house-boating paradise attracts over 10 million visitors a year. Lake Mead covers 550 miles of majestic shoreline and 247 square miles of area, which is twice the size of Rhode Island. Its capacity of 1 1/4 trillion cubic feet of water would cover the entire state of Pennsylvania one foot deep.
But, back to Hoover Dam itself, which is 726 feet tall and 1,244 feet long. At its base, Hoover Dam is 660 feet thick, which is 60 feet longer than two football fields laid end-to-end. Combined with its top thicknes
s of 45 feet, there is enough concrete (4.5 million cubic yards) in Hoover Dam to build a two-lane highway from Seattle, WA to Miami FL. Or imagine a four-foot wide sidewalk around Earth at its equator.
Hoover Dam is only about 35 miles from Las Vegas, NV making it a popular tourist destination of those visiting the casinos and nightlife that never sleeps. Over 20,000 vehicles a day cross Hoover Dam between Arizona and Nevada. Thousands from around the world take the Hoover Dam tour and ride the elevator down into the inner-workings of the dam. Hoover Dam offers ample parking in strategically located scenic areas overlooking the spectacular views across Hoover Dam to Lake Mead and the Colorado River through Black Canyon. Food, refreshments and tour guides make the visit even more enjoyable.
An often-asked question is how Hoover Dam can withstand the massive pressure and weight of Lake Mead, which is constantly trying to flow down river to the Gulf of California. It’s answered briefly this way. Hoover Dam curves against Lake Mead and is fortified against the massive rock walls of Black Canyon. When the water compresses against the curved walls of Hoover Dam, the canyon walls push back counteracting the awesome power of Lake Mead. This massive, but unseen, action squeezes the concrete arch together creating the mind-boggling strength of Hoover Dam.
A consortium called Six Companies, Inc., a joint venture of Morrison-Knudsen Company of Boise, Idaho; Utah Construction Company of Ogden, Utah; Pacific Bridge Company of Portland, Oregon; Henry J. Kaiser & W. A. Bechtel Company of Oakland, California; MacDonald & Kahn Ltd., of Los Angeles; and the J.F. Shea Company of Portland, Oregon. submitted a competitive proposal to build Hoover Dam. As the lowest qualified bidder at $48,890,955, Six Companies was awarded the contract.
It was given incentive bonuses and would be fined for each day construction overran the assigned schedule. As you can imagine, this triggered the starting gun of a race against time and resulted in a furious pace of around the clock construction. The race ended with the contractors winning. The result, Hoover Dam was completed almost two years ahead of schedule.
The Great Depression led to massive migration of the unemployed to Las Vegas in hopes of landing jobs building Hoover Dam. Men came from around the country, many bringing families and their life’s possessions hoping for employment. Living conditions were difficult and became substantially much worse when construction began, creating the shantytown known as Ragtown. Life was particularly difficult for the few blacks that were hired as token to government mandate.
The Colorado River had to be diverted before construction could begin. The riverbed had to be dredged clear of deep silt and sediment to expose a bedrock foundation for the building of Hoover Dam. It was a tedious process of digging four diversion tunnels through canyon walls that would divert river flow around the dam site to join the Colorado River farther downstream.
It was a daunting, difficult project. At that time there were no roads into Black Canyon, so initially, dam workers and equipment had to be brought by boat. Over time, roads were built and catwalks were stretched across the river. Summer temperatures often reached 140 degrees in the canyon and the winter months brought freezing temperatures.
Carving the diversion tunnels was a slow, tedious process that exposed dam workers to immense danger from blasting, falling rocks and diesel gas fumes spewed by the trucks that carried out blasting debris. Compressed air was circulated into the tunnels through large pipes. However, despite the difficulties, intramural competition of the crew shifts drove the workers, and the tunnels were completed almost a year early.
It took countless men to make even an inch penetration into the canyon walls. To quicken the process, a drilling “Jumbo Truck” was retrofitted with layers of platforms that were backed into the face of canyon walls. This enabled 20-30 men to simultaneously drill holes for blasting powder. Eight of these jumbo trucks were assembled and outfitted with lights making it possible for crews to work around the clock.
The blasting holes were filled with dynamite. It took a ton of dynamite for about every 14 feet of tunnel. After the explosion, dump trucks were loaded and hauled the rock downriver to spoil dumps along the canyon where it was stored for later use.
The diversion tunnels were lined with intricate concrete forms. A concrete base was poured first then the sidewalls were poured into moveable steel form sections. Rail mounted cranes were used to place the concrete sections. Concrete was pumped into the overhead forms with pneumatic concrete guns. Once complete, the total concrete lining was 3 feet thick.
A barrier had been installed across the Arizona side tunnels inlets. When the Arizona tunnels were ready, the barrier was removed with a blast and the water began flowing through the tunnels. Earthen and rock debris were trucked in and dumped from a trestle to block the Colorado River channel which forced the flow of water into the diversion tunnels. Eventually, cofferdams were built at the entrance to the other tunnels diverting water around the Hoover Dam construction site. With the Colorado River safely diverted around the dam site the actual project was ready to start.
Hoover Dam required over 3,250,000 cubic yards of concrete plus another million for the power plant, intake towers and other support structures. Two batch plants onsite were created to produce the concrete that was transported on railcars in large four and eight cubic yard buckets. An overhead cableway system lifted the buckets and lowered them to the forms. During peak production, one bucket was delivered about every 78 seconds.
The base of Hoover Dam alone required 230 individual gigantic blocks of concrete. The blocks were five-foot tall and of varying width, ranging from 25 square feet on the downstream face to 60 square feet on the upstream face. Columns were linked together with a system of alternating vertical and horizontal schemes.
< br />It is interesting to note that it would have taken about 100 years for the concrete to cool and properly cure without engineering intervention. The chemical heat generated by concrete setting was dissipated by imbedding over 582 miles of one-inch steel pipe through the interconnecting concrete blocks that circulated ice water. Its own ammonia refrigeration plant that cooled the water was capable of creating a gigantic 1000 pound ice block every day.
The cooling pipes were subsequently back-filled with concrete to create added strength. As an arch-gravity dam, the massive water pressure of up to 45,000 pounds per square foot at the base of Hoover Dam, is held back by gravity. The arch-curved structure against the lake reservoir dissipates that pressure into the canyon walls equally on the Arizona and Nevada side.
“High Scalers” had the dangerous job of hanging by rope above the canyon to blast and remove weakened and loose rocks from the face of the Black Canyon cliffs where the ends of Hoover Dam would join. The High Scalers risked their lives by not only performing their jobs, but also entertaining workers below with thrill-seeking and death-defying stunts along the cliff walls.
Some would call these guys crazy or at least driven by the adrenaline rush of exposure to extreme danger, or motivated by money. They were paid about 75 cents per hour versus the average of 50 cents that the regular Hoover Dam construction worker earned.
The High Scalers were carefully selected and had to be fearless, agile and extremely physically fit. Some were former sailors and even circus acrobats. Many were Native American Indians that lived in harsh terrains.
Danger from falling rocks was extreme and was the most common cause of death among those that died constructing Hoover Dam. Initially, hard hats were not distributed to dam workers, but High Scalers improvised by coating soft cloth hats with hot coal tar.
There was a particularly brave High Scaler named Louis Fagan who was known as the “human pendulum”. An obstructing large boulder protruded from the cliffs on the Arizona side. While hanging by rope, the transferring High Scaler would wrap his legs around Fagan’s waist, grasp the rope and together with a mighty leap, they would swing way out and around the boulder to reach scaling requirements on the other side. This acrobatic transfer took place twice daily until the job was complete.
Thrill seeking, entertaining and death defying, the High Scalers were perhaps the most interesting of all dam workers. In 1995, local sculptor Steven Liguori and Hoover Dam Spillway House concessionaire Bert Hansen decided to create a bronze high scaler statue in the likeness of Joe Kine, one of the last surviving High Scalers who worked on the Hoover Dam project. A clear picture of Joe Kine existed showing him in his working environment and was used as a guide to create the bronze figure. Upon completion, the statue was presented to Joe on September 30, 1995, Hoover Dam’s sixtieth anniversary.
Listed on the National Register of Historic Places in 1981, Hoover Dam was designated a National Historic Landmark in 1985. The dam and the power plant are operated by the Bureau of Reclamation of the U.S. Department of the Interior.
Hoover Dam Facts
- Construction period: April 20, 1931 – March 1, 1936
- Construction cost: $49 million ($736 million adjusted for inflation from 1936 to 2008)
- Deaths attributed to construction: 116; 96 of them at the construction site
- Dam height: 726.4 feet, second highest dam in the United States. (Only the Oroville Dam is taller)
- Dam length: 1244 feet
- Dam thickness: 660 feet at its base; 45 feet thick at its crest
- Concrete: 4.36 million cubic yards
- Maximum electric power produced by the water turbines: 2.08 gigawatts
- Approximate power output: 4 billion KWh per year (i.e. $200 million at $0.05 per kWh)Traffic across the dam: 13,000 to 16,000 people each day, according to the Federal Highway Administration
- Lake Mead (full pool)
· area: 157,900 acres, backing up 110 miles behind the dam.
· volume: 28,537,000 acre feet at an elevation of 1,221.4 feet
- With 8 to 10 million visitors each year, including visitors to Hoover Dam but not all traffic across the dam, the Lake Mead National Recreation Area is the fifth busiest National Park Service area