Hoover Dam in USA man-made miracle Arizona

Virtually all tourists traveling in Las Vegas and the Grand Canyon pass through the Hoover Dam or Hoover Dam. This huge concrete dam, equal in height to a 70-story building, pacified the stormy temper of the Colorado River. The Hoover Dam controls flood levels, supplies water and provides electricity to Arizona, California, as well as the "gambling capital of the United States" - Las Vegas (Nevada). Historians believe that it was not the gambling houses, but the construction of Hoover Dam that caused the development of Las Vegas, which turned from a village into a prosperous city.

Construction of the Hoover Dam

The construction of the Hoover Dam, begun in 1931, at the height of the Great Depression, contributed to the creation of new jobs for unemployed Americans. The construction of the dam was carried out in difficult conditions - the air temperature in summer rose to + 50 ° C. Climbers were especially dangerous, and tunneling workers suffered from excess carbon monoxide. However, there were more than enough applicants for vacancies. According to official figures, 96 people died during the construction of Hoover Dam. In 2000, a monument to rock climbers was erected near the entrance to the dam: a worker with a flashlight and in a protective helmet hangs on a rope belay over a cliff. It is interesting that the Hoover Dam was built in approximately the same years as the DneproGES (1932-1939). Moreover, the same engineer from the General Electric company, the American CJ Thomson, who was responsible for the installation of turbines and generators, took part in the construction of these hydraulic structures. In 1935, Soviet writers Ilf and Petrov visited the United States and visited a construction site. They describe this “marvel of engineering” with admiration: “Imagine a rough, mountainous Colorado River flowing through the bottom of a giant gorge, the walls of which are formed by high black-and-red rocks. And now, between these two walls created by nature, man created a third wall of reinforced concrete, blocking river flows.

The Hoover Dam is an engineering marvel

The construction of the Hoover Dam was completed in 1936, two years earlier than planned. It was named after former US President Herbert Hoover. At one time, that is, in the mid-30s of the last century, Hoover Dam was a marvel of engineering. During its construction, many technical innovations were applied: four channels were cut down to divert river flows from the construction site in the walls of the Black Canyon, and the dam itself was not built in the form of a solid monolith, but as a series of interconnected trapezoidal blocks - due to the smaller surface area, the concrete mixture cooled faster and solidified. Scientists have calculated that if the dam were built in one piece, then the complete solidification of concrete would be completed in 125 years.

Power plant at the Hoover Dam

The Hoover Dam is the tallest dam in the Western Hemisphere and one of the largest power plants in the United States. Today, the plant has 17 turbines with a total capacity of 2074 MW. According to experts, the equipment control automation system is so well-established that the power plant will be able to work independently for two years without the supervision of employees, until the pipes become overgrown with algae.

Hoover Dam Bypass

At the top of the Hoover Dam was Highway 93, connecting Arizona and the Mexican border. With the onset of the 21st century, frequent traffic jams led to the need to build a bridge across the Black Canyon, bypassing the dam. In October 2010, the Mike O'Callaghan-Pat Tillman Memorial Bridge, better known as the Hoover Dam Bypass, was opened 500 meters from the dam. The bridge bears the names of Mike O'Callaghan, the former governor of Nevada, and Pat Tillman, an American football player from Arizona who left a successful career and joined the US Army after the September 11, 2001 terrorist attacks to take revenge on the terrorists. The bridge is a grandiose arch structure 579 meters long and 270 meters high. $240 million was spent on the construction of the Hoover Dam Bypass. The bridge receives 17,000 cars daily, which made it possible to unload neighboring highways. Entertainment at the Hoover Dam 75 years have passed since the opening of the Hoover Dam, but this grand structure still attracts travelers. The Hoover Dam stands on the border of two states located in different time zones. Clocks are installed on the spillway towers, one of them shows the time of the right bank of Nevada, the other - the time of the left bank of Arizona. On one side of the dam, a defeated river flows calmly, on the other, the largest man-made lake in the United States, Mead, which has become a popular recreation area, stretches. Here you can go boating and water skiing, go fishing or sunbathe on the beach.

For visitors arriving by car, parking is available near the Hoover Dam. Parking costs about $7. Pick up your car must be before 17:00. You can walk along the Hoover Dam on your own or with a professional guide. Group tours are held strictly from 9:00 to 15:00. With a group, you can view the dam not only from the outside, but also from the inside. When descending into the engine room of the hydroelectric power station, do not take large items and luggage with you. It is allowed to take with you something small, as well as photographic equipment. All of these are anti-terrorist security measures.

HOW TO GET TO THE HOOVER DAM

The closest Big City from which you can get to the dam - Las Vegas. The journey by car will take only 30 minutes. Drive southeast on Route 93 to Boulder City. Inside the city, at the second intersection, you need to turn left and then we are already going to the very Hoover Dam. You can't drive across the dam from Nevada to Arizona. To do this, you will have to return to Highway 93 again, but pass over the Mike O'Callaghan - Pat Tillman bridge.

In the Black Canyon on the Colorado River on the border of two American states, Arizona and Nevada, a majestic dam rises. In 1935, Franklin D. Roosevelt named it after President Herbert Hoover, and September 30, 2011 marked the 76th anniversary of this event. From 1931 to 1936, the construction of a huge hydraulic structure was going on, the height of which was 221 meters in the end. The following are photographs that will show you step by step the construction of this structure.

1. View of the Hoover Dam at night, 1983. (AP Photo/Steve McPeak)
2. In this place, a few years later, the result of one of the largest projects in US history worth more than $ 165,000,000 will rise. Built 11 km from Las Vegas, the dam will provide electricity to 6 states. (AP Photo)
3. A reservoir of 588 square kilometers will cover these hills. And the flat-topped mountain, against which reclamation engineer Elmer L. Chapman is depicted, will become a small island that will rise only 14 meters above the surface of the water. Nevada, August 24, 1932 (AP Photo)
4. This is how a bird's eye view of the place where the most massive man-made structure built on Earth since the Pyramids of Giza, March 4, 1931, will be built. The contract to build the dam was awarded to the consortium of Six Companies, Inc., which offered the lowest cost, $48,890,995.50. (AP Photo / Fairfield Aerial Surveys) 5. September 17, 1930, the opening ceremony of construction in the state of Nevada. At the same time, Secretary of the US Department of the Interior Ray Lyman Wilbur announced that the dam, which bore the name Boulder, would be named Hoover Dam. (AP Photo)
5. September 17, 1930, the opening ceremony of construction in the state of Nevada. At the same time, Secretary of the US Department of the Interior Ray Lyman Wilbur announced that the dam, which bore the name Boulder, would be named Hoover Dam. (AP Photo)
6. September 19, 1930, a kind of symbol of the beginning of construction work was Ray Lyman Wilbur hammering a silver spike into a sleeper on the railroad tracks that connected the construction site and Las Vegas. Photographed from left to right: Congressman William Eaton of Colorado, Senator Kay Pittyman of Nevada, Secretary Wilbur and Senator Samuel Shortridge. (AP Photo)
7. Opening a post office in Boulder City. The town was built specifically for the builders. Postman J. L. Finney is congratulated by the staff of the Bureau of Reclamation. In the photo from left to right: V.R. Armstrong, head of United Pacific, R.F. Walter, Bureau of Reclamation Chief Engineer, Six Company Inc. carpenter, Finney Postman, Dr. Elwood Mead, Reclamation Commissioner, and P.V. Dent, assistant to Dr. Mead. (AP Photo)
8. Main street in the city of builders, Boulder City, Nevada, August 24, 1932. The cost of building the city was $2,000,000. (AP Photo)
9. A section of the Nevada-Arizona Highway, under which the power plant will be located, will run along the top of the dam on August 24, 1932. During the construction process, the largest lake created by man will appear here. (AP Photo)
10. In this picture you can see the drained bed of the Colorado River. Its waters were diverted to underground tunnels during the construction of the dam, on January 12, 1923. A few years later, the Hoover Dam will rise here. (AP Photo)
11. Foundation of the Hoover Dam at the bottom of the Black Canyon, Nevada, June 9, 1933. In a steel container with a volume of 8 cubic meters, the first batch of mortar is poured into a mold, where one of the walls is a sheer rock of the canyon. (AP Photo)
12. One of the tunnels for the diversion of the Colorado River. Start of construction work. Nevada, April 18, 1932. (AP Photo)
13. A group of builders near a special installation, Big Boer, which was used to work on the tunnels. From 24 to 30 jackhammers at the same time helped to build tunnels to divert the waters of the Colorado River.
14. The border of the states of Arizona and Nevada, the construction of the Hoover Dam. A crane lifts a tank with two cubic meters of mortar to cover the spillway walls with concrete. June 1933. (Library of Congress Prints and Photographs Division Washington, D.C.)
15. The process of creating a dam in the Black Canyon. Dozens of trucks deliver materials for construction. Nevada, date unknown. (AP Photo)
16. During the construction of the dam, concrete trapezoids were used with a cross section from 20 (on the outside) to 8 (on the inside) square meters. m. In total, 215 interconnected blocks were installed. The mortar was poured into the blocks gradually, which made it possible to create a more durable structure. After the solution solidified in the blocks, a new liquid solution was poured between them, which fastened the columns together. (Department of the Interior, Bureau of Reclamation)
17. The dam construction process is half completed. Work is going on around the clock with a few months ahead of schedule. The foundations for the power plants have already been laid at the base of the dam. A dark line can be seen in the center of the dam - these are voids left to speed up the solidification of the solution. (AP Photo)
18. Work on the construction of tunnels to divert the waters of the Colorado River. 50 tons of earth are taken out by trucks every minute. November 15, 1932. (AP Photo)
19. Huge concrete structures are visible at the bottom of the canyon, which will serve as the base of the Hoover Dam. Nevada, August 12, 1933. 6,000 cubic meters of mortar are poured into molds daily.
20. One of the outlet towers at the Hoover Dam, August 9, 1934. The height of the towers, two on each side of the dam, will be 120 meters. (AP Photo)
21. The construction of the Hoover Dam near Las Vegas, Nevada, January 9, 1932. (AP Photo)
22. The picture shows a view of the dam from above downstream of the river, February 1, 1935. (AP Photo)
23. Special concrete "plugs" weighing about 1,500 tons to close the tunnels that divert the waters of the Colorado River. When the tunnels are closed, the river will return to its course and fill the reservoir in front of the dam. (AP Photo)
24. View of the temporary suspension bridge and tunnels to divert the waters of the Colorado River, March 12, 1932. (AP Photo)
25. View from above on the Hoover Dam, July 16, 1935. A highway runs along the top of the dam, providing communication between the states of Nevada and Arizona. On the other side of the dam, 4 spillway towers are visible. (AP Photo)
26. The picture shows a rare view of the outer wall of the dam, May 1935. (Bureau of Reclamation, United States)
27. Painting metal structures on the weir wall at the Hoover Dam. The picture was taken between 1936 and 1946. (United States, Bureau of Reclamation, Library of Congress Prints and Photographs Division Washington, D.C.)
28. The final stages of the construction of the Hoover Dam. The dam already reaches 153 meters out of 222 planned. August 28, 1934. (AP Photo)
29. Completion of the construction of the Hoover Dam, whose height is more than 200 meters above the Colorado River, August 12, 1935. (AP Photo)
30. One of the generators of the power plant, Nevada, September 10, 1936. In just a month, the hydroelectric plant will become one of the main sources of electricity in the Western United States. (AP Photo)
31. The launch ceremony of the power plant on the Hoover Dam, September 11, 1936. The first 3,500 horsepower turbine was fired up by President Roosevelt at the push of a button in Washington. (AP Photo)
32. View of the Hoover Dam, captured by photographer Ansel Adams. This photograph is from the 1933-1942 National Parks and Monuments series of photographs. (U.S. National Archives and Records Administration)
33. View of the Hoover Dam. (AP Photo)
34. President Franklin D. Roosevelt at the Hoover Dam on the day it was renamed. (AP Photo)
35. Photograph shows President Franklin D. Roosevelt and Bureau of Reclamation project officer Walker Young (left) and military adviser to the president (right), September 30, 1935.
36. View of the Hoover Dam, March 13, 1936. The capacity of the dam is tens of thousands of liters of water per second. Behind the dam, the four spillway towers and part of Lake Mead are visible. (AP Photo)
37. Hoover Dam switchgear at night, April 27, 1937. 15 generators with a capacity of 115,000 horsepower and 2 generators with a capacity of 55,000 horsepower produce electricity, which is distributed here and sent through power lines to Los Angeles. (AP Photo/Department of the Interior)
38. Hoover Dam outlet towers, April 14, 1938. They supply water to turbines, which drives generators located at the bottom of the dam. The reservoir created by the dam has become a popular recreation area. (AP Photo)
39. The most powerful generators in the world on February 7, 1939. Their capacity was 82,500 kVA and the amount of energy produced was 130,000,000 kilowatt-hours per month. For the two years of operation of the hydroelectric plant, the Bureau of Reclamation, which built the dam, received $3,297,289. (AP Photo)
40. View of the Hoover Dam and Lake Mead, July 13, 1948. This is one of the most deserted areas of the country with an area of ​​​​21,000 square kilometers, so the planes of the sheriff's aviation detachment constantly patrol it. They help drivers if their cars break down on the road, look for lost travelers and conduct rescue operations in case of plane crashes in the desert. (AP Photo)
41. Sunset over the Hoover Dam, September 20, 1950. (AP Photo)
42. Ballet Rhythmettes during a concert number at the Hoover Dam, June 8, 1957. The Las Vegas Ballet has gained quite a bit of popularity since its inception. (AP Photo/V)
43. Unique design, Hoover Dam, May 11, 1953. A masterpiece of technical thought of the 20th century. Lake Mead, a reservoir above the dam, is popular with fishermen and boaters. (AP Photo)
44. The second largest dam in the world, Hoover Dam, February 26, 1957. Lake Mead, the largest man-made lake in the world, has become a favorite destination for fishing, boating and relaxing during the warmer months. (AP Photo/Union Pacific Railroad)
45. Steve McPeak climbed the Hoover Dam to protest against the policies pursued by President R. Reagan, December 8, 1982. (AP Photo/Frank Walters)
46. ​​Hoover Dam guards convince Steve McPeak to get off the ropes on which he hung over the Colorado River for three days and two nights, December 9, 1982. In this way, he expressed his protest against the policy pursued by R. Reagan. (AP Photo/Scott Henry)
47. The dam, named after President Hoover, is a unique hydraulic structure in the United States on the Colorado River in Black Canyon. Its construction lasted about 5 years and thousands of builders worked on its creation, and almost a hundred people died from accidents. 50. Millions of liters of water are forced through the pipes during strength testing, February 26, 2004. (AP Photo/Joe Cavaretta)
51. Safety test at the Hoover Dam, February 26, 2004. (AP Photo/Joe Cavaretta)
52. Aerial shot of the Hoover Dam and the construction of the bridge, June 12, 2009, Arizona. (Photo by Ethan Miller/Getty Images)
53. Aerial shot of the Hoover Dam and the construction of the bridge, June 12, 2009, Arizona. (Photo by Ethan Miller/Getty Images)
54. On October 19, 2010, the Mike O'Callahan-Pat Tillman Bridge was opened next to the Hoover Dam. The bridge is about 600 meters long and is located 270 meters above the Colorado River. The construction of the bridge, which provided additional capacity for the Nevada-Arizona highway, cost $240 million (Photo by Ethan Miller/Getty Images)

Airwolfhound / flickr.com Airwolfhound / flickr.com Airwolfhound / flickr.com View from Hoover Dam (Alexander Russy / flickr.com) Ron Reiring / flickr.com Ron Reiring / flickr.com Lauri Väin / flickr.com David Herrera / flickr. com Viator.com / flickr.com Construction of the O'Callaghan Bridge (Alan Stark / flickr.com) Henner Zeller / flickr.com Hoover Dam Towers (Joseph Francis / flickr.com) Joseph Francis / flickr.com Hoover Dam Clock Tower (Ian Lee / flickr.com) Joseph Francis / flickr.com Omshivaprakash H L / flickr.com Xiquinho Silva / flickr.com Hoover Dam Power Generators (Dennis Redfield / flickr.com) Joseph Francis / flickr.com Joseph Francis / flickr.com Power Generators Hoover Dam (Joseph Francis / flickr.com)

In the lower delta of the Colorado River, one of the most famous sights of the United States and Las Vegas is located - the Hoover Dam. The hydroelectric power station, which is a huge hydraulic structure more than 200 meters high, was built in the 30s of the last century.

Black Canyon - the place where the this building, is located near the state of Arizona and Nevada. The Hoover Dam got its name in honor of one of the American presidents, namely Herbert Hoover. The 31st head of a huge state accepted Active participation in the organization and progress of the construction of the dam, which earned him the honor of giving his name to such a grandiose construction project.

The Colorado River has repeatedly created many problems for the population living on its banks. Farmlands downstream suffered most often: with the melting of snow, river waters overflowed their banks and covered everything that was within their reach.

The main reason that served as a decisive step in the construction of the dam was the assumption of the designers that this is the only way to eradicate the annual problems with the high water of Colorado. In addition, hopes were pinned on the emerging new reservoir for the development of agriculture in the surrounding areas and the supply of drinking water to several areas of the state of California.

Signing of the Treaty - Colorado River Convention

For quite a long time, the main obstacle to the construction of the dam was the disagreement between the heads of neighboring administrative divisions. Most of them insisted that Colorado's resources should be distributed evenly among all likely consumers.

This fact contributed to the creation of a special committee, which included representatives of all those interested in the proceedings, including the main persons of the Neighboring States and the American government. All of them feared the intentions of the California government, which claims to receive the right to dispose of the main volume of water reserves.

The result of the activities of the above commission was the signing of a multilateral agreement - the Colorado River Convention, which legally fixed the mechanism for distributing the river reserve between interested parties.

Preparation of the project and investment resources

Hoover Dam, according to the design of its construction, needed a significant injection of funds, the source of which was the state budget. But the approval of the US authorities for the construction of such a large-scale hydraulic structure was received only after some time.

Despite the decision signed by Coolidge in 1928, the first investment was received only two years later. It was then that Hoover held the post of head of state. Hoover Dam was originally planned to be built in Boulder Canyon, which led to the construction project being referred to as the Boulder Canyon Project, despite the fact that Hoover Dam was built in Black Canyon.

The most difficult working conditions

Leading US companies were appointed as construction contractors. The number of workers involved in the process of creating a hydroelectric power plant was simply incredible: the largest number of workers was recorded in 1934 - more than 5,200 people.

View of the Hoover Dam (Joseph Francis / flickr.com)

A feature of the contract agreement was a ban on hiring Asians, and a limit on employing Africans - only about 30 black people were allowed to work in the lowest paid jobs.

During construction, a special settlement for workers and builders was to be built next to the Hoover Dam. However, the plans were changed as the work schedule was revised to increase the number of vacancies. All these factors influenced the course of building the town, which was not completed by the arrival of the main number of mercenaries. The builders had to live in temporary barracks near the Hoover Dam.

It is worth noting the terrible working conditions. Lack of normal living work time and the dangers that await workers at every turn due to neglect of safety, became the reasons for the strike that took place in 1931, which was not crowned with success - the police were ordered to disperse the strikers with the use of force. After these events, the state authorities decided to accelerate the pace of construction, and a year later the mercenaries were settled in permanent homes in the adjacent completed city.

Joseph Francis / flickr.com

Until the very end of construction work on the territory of Boulder City, prostitution, the sale of any alcoholic beverages, and gambling were strictly prohibited. At the same time, in fact, the ban lasted another forty years, and gambling has not been lifted to this day, which makes this city the only one in Nevada where such a taboo operates.

The Hoover Dam was born in the most difficult inhuman conditions. People working in deep tunnels suffocated from carbon monoxide, but the management flatly refused to take responsibility for the illness and death of their subordinates.

The Hoover Dam and the history of its creation were distinguished by the fact that it was here that workers first used helmets that protect their heads from impacts. However, a total of 96 people were victims of the negligence of the project managers, who neglected the observance of technical safety rules.

Construction works

The Black Canyon, in which the Hoover Dam was to be built, was quite narrow and played a demarcating role between Nevada and Arizona. It was planned to divert water in the opposite direction from the construction point using 4 tunnels, the total length of which is almost 5 km.

Hoover Dam, Arizona/Nevada, USA (Ron Reiring / flickr.com)

The Hoover Dam has a concrete base that was poured in 1933. For this purpose, the nearest non-metallic deposits were specially opened and factories for the production of concrete were built.

Faced with the problems of cooling the concrete mixture during the construction of such a giant dam, the builders had to make adjustments to the original plan, and then the Hoover Dam was erected from many individual trapezoidal columns interconnected. This construction methodology allowed to significantly speed up the process of concrete hardening.

The pit for the hydroelectric power plant was supposed to be dug simultaneously with the main reservoir pit. All earthworks were completed by 1933.

Hoover Dam Power Generators (Joseph Francis / flickr.com)

Three years later, the first electric generators were installed and for the first time received electricity. To date, the Hoover Dam houses 17 electrical generators, which reach a capacity of up to 2074 MW.

They balance the consumption of electricity needed for the needs of the population and production in the western United States. 25 years ago, the power management system at the Hoover Dam was modernized and equipped with modern computers.

The architectural appearance of the dam

The outer part of the Hoover Dam was supposed to look like an ordinary wall, decorated with a neo-Gothic balustrade. The creators were not going to take the issue of the architecture of the building of the hydroelectric power plant seriously, since the first priority was to complete the construction as soon as possible. At the same time, this decision caused a whole wave of critical discussions, and in the end, it was decided to work out the architectural appearance of the Hoover Dam.

Los Angeles-based guest architect Gordon Kaufman has made a dramatic difference by approving new project referring to the art deco style. In addition to the towers on top of the dam, his idea was to place clocks on spillway towers.

Legal name: Hoover Dam

The Hoover Dam has not always had its rightful name. The fact is that in addition to the original "Boulder Dam" associated with the construction site of the dam, there were other factors that prevented the legendary structure from bearing a well-deserved name.

Some time later, after the dam was officially named after President Herbert Hoover, he lost the election, giving way to Franklin Roosevelt. In the US Congress, they again proposed returning the name to the original version. And only after the death of President Roosevelt, the project to return the design named after Hoover was signed by the next American head.

New O'Callaghan Bridge

Until 2010, a highway connecting the state of Arizona with the border of Mexico passed through the Hoover Dam. The part of the road adjacent to the dam did not meet the requirements of the highway and the number of passes Vehicle.

Construction of the O'Callaghan Bridge (Alan Stark / flickr.com)

Also, the winding, dangerous two-lane road had some tricky hairpin turns and low-visibility bottlenecks.

The terrorist attack in 2001 in New York left its mark on the traffic system. In order to avoid repeated terrorist attacks, a more thorough inspection of cars was organized, which slowed down the traffic of vehicles and increased traffic jams at the entrance.

But the O'Callaghan Bridge, opened 6 years ago, near the Hoover Dam, has significantly reduced the flow of cars passing through the dam.

Significance of the Hoover Dam today

The erected Hoover Dam significantly affected the water regime of the Colorado River and its ecological system. Such negative impacts are inherent in all artificial hydraulic structures, however, the benefits of the dam are significant: the river canyon got rid of frequent floods.

The Hoover Dam or Dam is considered the largest in the United States. It is located in the narrow Black Canyon formed by the Colorado River, on the border of two states - Arizona and Nevada. This is not only a hydroelectric power plant, but also the main element of the melioration and protection system. settlements from floods. The dam was built a few kilometers from Las Vegas and is one of America's most famous landmarks. Tourists combine visiting the casino and this interesting hydraulic structure.

Construction

The construction of the dam began in 1931. President Herbert Hoover allocated public money for the construction of the Hoover Dam. The work was carried out during the Great Depression. Thousands of people flocked to the dam construction site in search of work. Especially for the workers, it was decided to break the small town of Boulder City. But they did not manage to build housing on time, so people settled in a camp, broken up in haste. The conditions were so unbearable that the workers could not stand it and went on strike in the summer of 1931, which was brutally suppressed.

More than five thousand people participated in the construction of the Hoover Dam, gambling, alcohol and prostitution were prohibited for them. Many technological innovations were used in the construction of the dam. One of them is helmets that protect the head of workers.

Significance of the dam

The grand opening of the Hoover Dam took place in 1935, but the final work was completed a year later. The dam quickly became a famous landmark. Nine million tourists come to see it every year. The Hoover Dam supplies water to the states of Nevada and Arizona while controlling flood levels. There is an assumption that it was not the gambling houses, but the construction of the dam that became the impetus for the development of Las Vegas, which quickly turned from a village into a prosperous city.

architectural features

The very first design of the Hoover Dam assumed a simple architectural solution for the object: the outer wall was to be an ordinary wall, framed by a neo-Gothic balustrade. The building of the power plant was not supposed to differ from the factory shop. The project was criticized by many contemporaries, which was the reason for its alteration. This was done by Gordon Kaufman, an architect from Los Angeles. He proposed the exterior of the buildings in the Art Deco style. The upper part of the dam received decoration in the form of turrets growing directly from the dam. There are two clocks on the spillway towers: one shows Mountain time, the second - Pacific North American time.

The Hoover Dam in the United States is built of trapezoid columns and is considered the largest man-made structure erected since the time of the pyramids.

One of the largest dams in the world has an observation deck that offers a magnificent view of Lake Mead, formed as a result of the construction of the dam. A monument was also built nearby - a monument to those who died during construction.

Prior to the construction of the dam, the Colorado River often showed its turbulent temper, often flooding downstream farmlands during snowmelt in the Rocky Mountains. The designers of the dam planned that its construction would help smooth out fluctuations in the level of the river. In addition, the reservoir was expected to give impetus to the development of irrigated agriculture, as well as become a source of water supply for Los Angeles and other areas of Southern California.

At the same time, one of the obstacles to the implementation of the project was the doubts of the states lying in the Colorado River basin about the fair distribution of water resources between consumers. There were fears that California, with its influence, financial resources, and lack of water, would lay claim to much of the reservoir's water resources.

(ca. 1928)* - Engineers and politicians view dam site at Black Canyon.

As a result, in 1922, a commission was created, which included one representative from each of the interested states and one from the federal government (Herbert Hoover, then Secretary of Commerce in the government of President Warren Harding). The result of the activities of this commission was the Colorado River Convention signed on November 24, 1922, which fixed the methods for dividing water resources. The signing of this document, called the Hoover Compromise, opened the way for the construction of the dam.

The construction of such a large-scale hydraulic structure required the attraction of significant funds from state budget. The funding bill was not immediately approved by the US Senate and the White House. Only on December 21, 1928, President Calvin Coolidge signed a bill approving the implementation of the project. Initial appropriations for the construction of the dam were allocated only in July 1930, when Herbert Hoover was already president.

The original plan was to build a dam in Boulder Canyon. Boulder Canyon). Therefore, despite the fact that it was finally decided to build a dam in the Black Canyon, the project was called the Boulder Canyon Project.

The construction of the dam was planned in a narrow canyon on the border between Nevada and Arizona. To divert water from the Colorado River away from the construction site, four tunnels with a diameter of 17.1 m were drilled in the stone walls of the Black Canyon. The total length of the tunnels was 4.9 km. The construction of the tunnels began in May 1931. The lining of the tunnels was made of concrete 0.9 m thick, as a result, the effective diameter of the conduits was 15.2 m. and disposal of excess water. The fact that the spillway is carried out not through the body of the dam (as on the Sayano-Shushenskaya hydroelectric power station, built later on the same principle as the Hoover dam), but through tunnels located in the surrounding rocks, gives stability to the dam.

To isolate the construction site and prevent possible flooding by the waters of the river, two caisson dams were built. The construction of the upper dam was started in September 1932, despite the fact that the outlet tunnels had not been completed at that time.

In order to ensure the safety of work, before the start of the construction of the dam, measures were taken to clean the walls of the canyon from free-lying stones and rocks: they were blown up with dynamite and thrown down.

(1931)* - The first blast of the dam construction. Cameras are rolling as the blast goes off.

The contract to build the dam was awarded to Six Companies, Inc., a joint venture between the Morrison-Knudsen Company of Boise, Idaho; Utah Construction Company (Ogden, Utah); Pacific Bridge Company (Portland, Oregon); Henry J. Kaiser & W. A. ​​Bechtel Company (Oakland, California); MacDonald & Kahn Ltd. (Los Angeles) and J. F. Shea Company (Portland, Oregon).

Many thousands of workers participated in the construction ( maximum amount- 5251 people - in July 1934). According to the terms of the construction contract, the employment of immigrants from China was not allowed, and the number of black workers during construction did not exceed thirty people employed in the lowest paid jobs. It was planned that a whole town - Boulder City - would be erected for the builders next to the dam, but the construction schedule was adjusted in favor of accelerating and increasing the number of jobs (this was done to reduce the massive unemployment that resulted from the Great Depression). In this regard, at the time of the appearance of the first workers, the city was not yet ready, and the builders of the dam spent the first summer in temporary camps. The delay in the delivery of housing and dangerous working conditions led to a strike that took place on August 8, 1931. The workers' uprising was dispersed with guns and clubs, but the pace of construction in Boulder City was increased, and by the spring of 1932 the workers had moved into permanent housing. Prostitution, gambling, and the sale of liquor were prohibited in Boulder City during construction. The ban on the sale of alcohol in the city lasted until 1969, and the ban on gambling still remains (this is the only such city in the state of Nevada).

(ca. 1931)^^ - Workmen supported by lines from the top as they did high scaling on canyon walls during construction of the dam.

(1932)* - View from above the Colorado River looking upstream towards the site of Hoover Dam which is at the bend in the river. On the right we can see the lower portals of the Arizona water diversion tunnels.

	(ca. 1932)**# - Blasting away the sides of the canyon.

The construction of the dam was carried out in difficult conditions. Part of the work was carried out in tunnels where workers suffered from excess carbon monoxide (some workers became disabled or even died as a result). The employer also announced that these diseases are the consequences of ordinary pneumonia, and he is not responsible for this. At the same time, the construction of the Hoover Dam was the first construction site to use safety helmets.

A total of 96 people died during construction. The first person to die building a dam was topographer J. Tierney, who drowned in Colorado in December 1922 in the process of choosing the best site for construction.

(ca. 1933)^#^ — Government officials and politicians take a ride in one of the 30 ft. diameter pipe sections.

The first concrete was poured into the foundation of the dam on June 6, 1933. For the production of concrete, local deposits of non-metallic materials were discovered, and special concrete plants were built.

Since works of this scale had never been carried out before, a number of technical solutions used in the construction process were of a unique nature. One of the problems that engineers had to face was the cooling of concrete. Instead of a solid monolith, the dam was built as a series of interconnected trapezium-shaped columns - this allowed the excess heat released during the solidification of the concrete mixture to dissipate. Engineers have calculated that if the dam were built as a monolith, it would take 125 years for the concrete to cool completely to ambient temperature. This could lead to cracking and collapse of the dam. In addition, to speed up the cooling process of the concrete layers, each form into which the pour was carried out contained a cooling system of inch metal pipes, into which river water. The hardening process of the concrete from which the dam is built has not been completed to this day.

In total, 600 thousand tons of Portland cement and 3.44 million m³ of aggregate were mixed into the concrete required for the construction of the dam body. The Hoover Dam at the time of its completion became the most massive artificial structure on earth, exceeding the mass of the masonry of the Giza Pyramids - the concrete used would be enough to build a 20-centimeter thick concrete road 5 meters wide from San Francisco to New York, that is, crossing the entire US from the Pacific to the Atlantic

Workmen stand in completed spillway tunnel lining at Boulder Dam.* The spillway tunnel is 50 feet in diameter and 2,200 feet in length. Click to view a detail diagram showing Boulder Dam's piping and penstock configuration.

(1934)* - Five workmen peer at the inside one of the four diversion tunnels. Behind them on the right is another tunnel.

The dam was originally to be built in Boulder Canyon, so despite the fact that construction actually began in Black Canyon, it was originally called "Boulder Dam" in official documents. But already at the official opening ceremony of the construction, Secretary of the US Department of the Interior Ray Wilbur announced that the dam would be named Hoover in honor of the current US president. With this statement, Wilbur continued the established tradition of naming the largest dams in the United States after the presidents in power at the time of their construction (for example, Wilson Dam or Coolidge Dam). On February 14, 1931, the US Congress approved the official name of the Hoover Dam.

In 1932, Hoover lost the election to Democratic nominee Franklin Delano Roosevelt. Immediately after the new president took office, the US administration initiated the renaming of the dam to the "Boulder Dam". No official decision was made on this matter, however, Hoover's name disappeared from all official documents and tourist guides of that time.

In 1947, two years after Roosevelt's death, California Congressman Jack Anderson submitted a draft decision to return the Hoover Dam. On April 30, the corresponding bill, approved by the Senate, was signed by the president; since then, the dam has had its modern name.

(ca. 1933)^^ — Construction was a 24/7 operation. In this view we can see the base of the dam face on the far side of a pool of water, construction equipment and night lights.

(ca. 1933)* - Hoover Dam initial construction phase. Note the width and depth of the dam as it goes up.

(ca. 1933)* - View of the on-site cement plant at Hoover Dam.

Wooden forms seen above the dam.*

(1934)^ - Hoover Dam takes shape from the concrete columns in which it was poured.

(ca. 1934)* - Upstream face and top of Boulder Dam.

Before and After

(1930)*		(1934)^

(1934)^^ - Looking down at the construction of one of the Nevada intake towers. These towers permit and control flow of water into tunnels and then to power turbines.

(1934)#* - A raised view of the Hoover dam while it was under construction. Most of the concrete has already been poured, and work seems to be concentrated on the top and at the base of the dam.

(ca. 1934)* — The cement forms for the two power plants can clearly be seen.

(ca. 1934)* — A closer look at the cement forms for the two power plants. Construction workers can be seen throughout.

(ca. 1935)* - View of the giant turbine runner before its installation at Hoover Dam power plant. The fin-circular like pieces of metal between the two flanges are the vanes.

(ca. 1936)* - View of the upper generator room at Hoover Dam, on the Nevada side, where there are eight generators. (The Arizona side has nine.)

(1935)* - Hoover Dam close to completion. Water can already be seen at the base of the dam.

(1935)^ - The upstream face of Hoover Dam slowly disappears as Lake Mead fills.

	(1935)**# - View of the graceful intake towers whose gates control the release of the reservoir water.

(ca. 1935)* - View of the intakes as the water level nears the top of Hoover Dam. Cars are parked along the roadway over the dam. The Arizona Spillway can be seen on the other side of the canyon.

(1935)^#* — View of Hoover Dam as seen from above the Arizona Spillway side looking towards the intake towers as the water continues to rise.

(n.d.)**# – Detailed drawing of the dam and power plant from U.S. Department of Interior.

(1934)* - View of the diversion tunnel, showing the entrance of one of the 16 tunnels which lead to the turbines. The water will then turn turbine generators to create the electricity.

(ca. 1934)* - The needle valves of the power plant under construction. The valves are 13 feet in diameter and will dicharge the water back into the Colorado River once the water does its work by turning the turbine generators.

(1936)* - Hoover Dam during the final stages of testing. Three of the 13 foot diameter penstocks are fully opened.

(1936)** - Another view of the final testing showing water flowing out of all six of the penstocks on one side of the dam.

And now she looks like this.