Address: USA, 48 km from Las Vegas, Colorado River
Start of construction: 1931
Completion of construction: 1936
Height: 221 m
Coordinates: 36°00"58.0"N 114°44"15.5"W
Short description
Almost all tourists traveling to Las Vegas and the Grand Canyon pass through the Hoover Dam or Hoover Dam.
Bird's eye view of Hoover Dam
This huge concrete dam, equal in height to a 70-story building, tamed the violent nature of the Colorado River. The Hoover Dam controls flood levels, supplies water and provides electricity to Arizona, California, and the “gambling capital of the United States” - Las Vegas (Nevada).
Historians believe that it was not 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 Hoover Dam
Construction of the Hoover Dam, begun in 1931 at the height of the Great Depression, helped create new jobs for unemployed Americans. The construction of the dam was carried out in difficult conditions - the air temperature in the summer rose to +50°C. The work of rock climbers was particularly dangerous, and workers drilling tunnels suffered from excess carbon monoxide. However, there were more than enough applicants for vacant positions. According to official data, 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 a safety helmet hangs on a rope harness over a cliff.
I wonder what The Hoover Dam was built around the same years as the Dnieper Hydroelectric Power Station (1932 - 1939). Moreover, the same engineer from the General Electric company, the American C.G. 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 “miracle of engineering” with admiration: “Imagine the stormy, mountainous Colorado River flowing along the bottom of a giant gorge, the walls of which are formed by high black and red rocks. And between these two walls created by nature, man created a third wall of reinforced concrete, blocking the river flows.”
Hoover Dam - an engineering marvel
Construction of the Hoover Dam ended 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 miracle of engineering. During its construction, many technical innovations were used: to divert river flows from the construction site, four channels were cut out in the walls of the Black Canyon, and the dam itself was built not as a solid monolith, but as a series of interconnected trapezoidal blocks - thanks to the smaller surface area, the concrete mixture cooled faster and hardened. Scientists have calculated that if the dam had been built in one piece, the concrete would have completely hardened in 125 years.
Hoover Dam Power Plant
Hoover Dam is the tallest dam in the Western Hemisphere and one of the largest power plants USA. Today, the station has 17 turbines with a total capacity of 2074 MW. According to experts, the equipment control automation system is so well adjusted that the power plant will be able to operate independently for two years without employee supervision, until the pipes become overgrown with algae.
Hoover Dam Bypass
At the top of Hoover Dam was Highway 93, connecting Arizona and the Mexican border. With the advent 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 is named after Mike O'Callaghan, the ex-governor of Nevada, and Pat Tillman, an American football player from Arizona who left successful career and joined the US Army after the terrorist attacks of September 11, 2001, to take revenge on the terrorists. The bridge is a grandiose arched structure 579 m long and 270 m high.
$240 million was spent on the construction of the Hoover Dam Bypass. The bridge accommodates 17 thousand cars daily, which made it possible to relieve congestion on neighboring highways. Activities at Hoover Dam It's been 75 years since the Hoover Dam opened, but this grand structure still attracts travelers. The Hoover Dam stands on the border of two states located in different time zones. There are clocks on the spillway towers, some of them show the time of the right bank of Nevada, others - the time of the left bank of Arizona. On one side of the dam, the defeated river flows calmly, on the other, the largest man-made lake in the United States, Lake Mead, stretches, which has become a popular recreation area. Here you can go boating, water skiing, fishing or sunbathing on the beach.
Hoover Dam(Hoover Dam, Boulder Dam) is one of the largest and probably the most famous dam in the USA. It is built on the border of Nevada and Arizona in the narrow Black Canyon formed by the Colorado River. The Hoover Dam is not only a large hydroelectric power station, but also the main component of the reclamation and flood control system in the southwestern United States.
The Hoover Dam, located forty kilometers from Las Vegas, is on the “must-see” list of tourists vacationing in the “Entertainment Capital of the World” (as well as the famous Grand Canyon) and is one of the most popular attractions in the United States.
Hoover Dam. Ideas and projects
Black Canyon on the Colorado River, photo from 1871 Already at the beginning of the 20th century, the idea arose to build a complex of hydraulic structures on the Colorado River. The need for such a decision was due to the capricious “character” of the river (for example, in 1905, after heavy rains, the Colorado changed its course, forming the Salton Sea Lake in California), as well as the desire to use its waters for irrigating fields and development Agriculture
in the arid regions of the southwestern United States. With the development of electric power, Colorado's high hydroelectric potential has also become very attractive. In 1922, the Bureau of Reclamation (a division of the Department of the Interior that deals with the country's water resources) submitted a report to the US Government that recommended building a dam on the Colorado River in the Boulder Canyon area (hence the project's first name, Boulder Dam). Subsequent geological surveys showed that more suitable place
At that time, there were serious political obstacles to starting construction of the dam. US jurisprudence knows a lot of litigation between the use of water from rivers flowing through several states. Before work began, it was necessary to reach a compromise to eliminate possible future lawsuits from one or another interested state. It was for this purpose that a commission was formed in 1922, which included representatives of seven US states through whose lands the Colorado River and its tributaries flow (Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona and California). Herbert Hoover, who was then Secretary of Commerce in the government of Warren Harding and later became President of the United States, also participated in the work of this commission. The result of the commission’s work was the signing of an agreement on the procedure for using water resources Colorado.
The next obstacle to the construction of the dam was the issue of financing the grandiose project. Congressmen and senators from California, most interested in the implementation of the project, repeatedly raised this issue in the US Congress, but only after the devastating flood of the Mississippi in 1927 and the death of hundreds of people as a result of the destruction of the St. Francis Dam in Los Angeles, a corresponding decision was made.
On December 21, 1928, US President Calvin Coolidge signed legislation authorizing and funding the Boulder Canyon Project. In addition to the “main” dam, which became known as the “Hoover Dam,” the project provided for the construction of another dam downstream in the Colorado, the Imperial ( Imperial Dam), as well as the All-American Channel ( All-American Channel), designed to provide water for the extremely fertile but arid lands of Southern California.
The project for the future Hoover Dam was developed by engineers of the US Bureau of Reclamation under the leadership of the famous “dam designer” John Savage, who later participated in the creation of the Shasta Dam on the Sacramento River in Northern California, the largest dam in the United States, the Grand Coulee Dam in Washington State, and also proposed a project built already in In the 21st century, the world's largest hydroelectric power station, the Three Gorges hydroelectric power station in China.
It was decided to build a so-called “arch-gravity” concrete dam, which has the shape of an arc in plan, convex upstream of the river. The thickness of the dam at the base was supposed to be about two hundred meters, and at the top - only fourteen, and automobile traffic was provided for along the dam.
John Savage and a group of engineers explore the site of the Hoover Dam in Black Canyon
Hoover Dam. Builders and construction
In July 1930, Herbert Hoover, already President of the United States, allocated from the country's budget the first part of the money needed to build the dam. In January 1931, a tender was announced for the construction of the dam. Anyone could obtain the documentation for as little as five dollars, but each bid from a potential contractor had to be backed by a two million dollar bond, and the winning bidder was required to provide a cash guarantee of five million dollars. One of the mandatory conditions was a strict construction period - seven years. If the contractor did not meet the allotted time for construction, the contract provided for large penalties.
The auction was won by the consortium Six Companies("Six Companies"), uniting construction companies from Utah, Idaho, Oregon and California. Frank Crowe, an experienced engineer with extensive experience in dam construction, was appointed construction manager. He was responsible for several important inventions that made it possible to significantly speed up the construction of such huge concrete structures as dams.
The Hoover Dam was built during the Great Depression, and the Black Canyon area was very far from large cities.
Las Vegas was then just a small town in the desert, whose entire significance was determined by the railroad passing through it. But it was Las Vegas that became the transit point for thousands of unemployed people from all over America who flocked to the construction of the new dam. Already in 1930, construction began on a railroad connecting Las Vegas with the “construction site” of the future Hoover Dam. The project envisaged, even before the construction of the dam began, to build a city for its builders - Boulder City. But with the goal of getting work done as quickly as possible people US President Herbert Hoover ordered work to begin in the spring of 1931, six months earlier than planned. The city for the builders was not yet ready and people were forced to live in temporary camps, very poorly adapted for the hot climate of Nevada. Heavy and very hazardous conditions labor combined with the lack of adequate housing and all this in conditions of terrible heat (and that summer in Nevada the temperature often exceeded 45 ° C) - strikes were inevitable. In August 1931, workers presented a number of demands to the construction administration. Frank Crow, known for his very tough character, responded by ordering the dismissal of almost all workers and ordered the hiring of new ones for construction. It wasn't until late 1931, when builders began moving into new homes in Boulder City, that living conditions began to improve.
Cleaning the canyon walls
Panorama of Boulder City, 1933
One of the drillers who laid tunnels during the construction of the dam The construction of the Hoover Dam was a very complex engineering task. First, it was necessary to strengthen the walls of the canyon, exposing the rocks on which the concrete arch of the dam would later rest, and at the same time protecting the workers below from falling stones ( main reason accidents during dam construction). This work was carried out by rock climbers using jackhammers and dynamite.
In order to drain the site of the future construction site, it was necessary to divert the waters of the Colorado River. Two temporary, so-called “caisson” dams were built, located above and below the dam construction site. Four huge tunnels were drilled into the rocks of the canyon, two from the Nevada side and two from the Arizona side. The diameter of the tunnels was about seventeen meters, and after lining with concrete - about fifteen meters, the total length of the Hoover Dam tunnels was about five kilometers. Construction of the tunnels began in May 1931, and already in November 1932, the river was diverted into the “Arizona” tunnels (the “Nevada” ones had reserves in case of floods). After construction of the dam was completed, the tunnels were partially plugged and partially used to discharge water.
In June 1933, a year and a half earlier than planned, concrete work began on the Hoover Dam. For the manufacture of concrete in Nevada, two plants were built near the construction site. Concrete was delivered in special containers with a volume of more than six cubic meters, each of which weighed about eighteen tons when filled. These huge tubs were transported to the canyon on special wagons and then transported to the unloading site using ropes.
Innovative solutions were widely used during the construction of the Hoover Dam. For example, in order to avoid cracking of concrete when it hardens, the dam’s structure was not monolithic, but consisted of many columns, between which pipes were laid. River water was supplied through pipes, cooled by powerful refrigeration units. After the concrete columns hardened, the spaces between them were filled with mortar.
Almost completed Hoover Dam before flooding In total, more than two million four hundred and eighty thousand cubic meters of concrete were used to create the Hoover Dam. Another eight hundred and fifty thousand cubic meters went to the construction of the power plant and other structures of the dam complex. At the time of construction, it was the largest structure in the world created by man.
The architectural design of the dam buildings was made by Gordon Kaufmann in the Art Deco style popular at that time (in which, in particular, the famous New York skyscrapers Chrysler Building and Empire State Building were built). In addition, motifs from the Navajo and Pueblo Indian peoples living in this region were used in the design. Interestingly, each of the two towers of the Hoover Dam has a clock, one of which shows the time of the US Mountain Time Zone, in which the state of Arizona lives, and the other - the Pacific Time Zone, in which the state of Nevada belongs.
Hoover Dam. Water and electricity
US President Franklin Roosevelt at Hoover Dam Construction of the Hoover Dam was completed earlier than planned. On September 30, 1935, US President Franklin Roosevelt held a ceremony to open the dam (although construction of the power plant and some other work were completed only in the spring of 1936).
Given that Herbert Hoover was Roosevelt's election rival, it is not surprising that during the latter's presidency the new dam was known as the "Boulder Dam." Only in 1947 the dam was given back its name, which had been approved by the US Congress before construction began.
According to official statistics, one hundred and twelve people died during the construction of the dam. Forty-two more workers are believed to have died from poisoning carbon monoxide during tunneling.
The construction of a giant dam on the Colorado River allowed, along with others hydraulic structures, provide irrigation to Southern California's fields and eliminate the threat of devastating floods. Electricity generated at the Hoover Dam provided powerful impulse
development of the southwestern United States, including the famous Las Vegas. In the eighties and nineties of the 20th century, the power plant was reconstructed, so that today it remains one of the most powerful in the USA. Nevada consumes about a quarter of its energy production
Hoover Dam and Lake Mead
Such an unusual object as the Hoover Dam could not help but attract the attention of tourists. Almost immediately after construction was completed, in 1937, the dam complex was opened to tour groups. As the popularity of nearby Las Vegas grew, the number of visitors increased. In 1996, for the first time, more than a million people visited Hoover Dam in one year.
Hoover Dam carried Highway 93, connecting Arizona through Nevada and Idaho to Montana. This road also connects Las Vegas and Phoenix, one of the fastest growing cities in the United States. After the tragic events of September 11, 2001, for safety reasons, vehicle traffic along the dam was limited and trucks were prohibited. In 2003, construction began on a bridge across the Colorado, called the Hoover Dam Bypass, half a kilometer downstream from the Hoover Dam. In October 2010, traffic opened on the new bridge, named in honor of Nevada Governor Mike O'Callaghan and famous Arizona football player Pat Tillman, who was killed in Afghanistan.
Today, many decades after its construction, the Hoover Dam continues to be a magnificent example of the engineering genius of its designers, the dedicated work of its builders, and one of America's most famous landmarks.
Panorama of Hoover Dam and Mike O'Callaghan - Pat Tillman Memorial Bridge An hour's drive from Las Vegas is a unique property recognized as a historical landmark and architecture of the United States of America is the Hoover Dam. The concrete dam, the height of a seventy-story building (221 m), is amazing. The huge structure is wedged between the ledges of the Black Canyon and has been holding back the unruly temper of the Colorado River for more than 80 years.
In addition to the dam and the operating power plant, tourists can visit the museum complex, admire the panoramic views, and cross the border between Nevada and Arizona along an arched bridge located at an altitude of 280 meters. Above the dam level is the huge man-made Lake Mead, where fishing, boating and recreation take place. 
History of the Hoover Dam
Local Indian tribes call the Colorado the Great River Serpent. The river originates in the Rocky Mountains, which are the main ridge in the Cordillera system of North America. Every spring, a river whose basin is more than 390 square meters. km, overflowed with melt water, as a result of which it overflowed its banks. It is not difficult to imagine the enormous damage that floods caused to farms. 
By the twenties of the last century, the issue was so acute that curbing destructive force Colorado became a political decision. Many people want to know why the dam was built, and the answer is quite simple - to control the water level of the river. Also, the reservoir was supposed to solve the problem of water supply to areas of Southern California and, first of all, to the rapidly growing Los Angeles. 
The project required serious capital investment, and as a result of debates and discussions, an agreement was signed in 1922. The government representative was Herbert Hoover, who was then Secretary of Commerce. Hence the name of the document - “Hoover Compromise”. 
But eight long years passed before the government allocated the first subsidies for the ambitious project. It was during this period that Hoover was in power. Despite the fact that after the project changes it was known where the new construction site was located, it was called the Boulder Canyon Project until 1947. Only 2 years after Hoover's death in 1949 did the Senate make a final decision on this issue. From that moment on, the dam began to officially bear the name of 31 US presidents. 
How the Hoover Dam was built
The contract for the construction of the dam, as a result of a competitive selection, went to a group of companies Six Companies, Inc, which are commonly called the Big Six. Construction began in May 1931 and was completed in April 1936, significantly ahead of schedule. The project involved the use of non-standard engineering solutions and good organization of the construction process:
- The canyon walls and ledges were cleared and leveled during the initial phase of the work. A monument was erected at the entrance to the Hoover Dam to the rock climbers and demolition workers who risked their lives every day.
- Water was diverted from the work site through tunnels, which still exist today, providing partial water supply to the turbines or its discharge. This system reduces the load on the dam and contributes to its stability.
- The dam is designed as a series of interconnected columns. A system was created to cool concrete structures using running water to speed up the hardening of concrete. Research in 1995 showed that the concrete structure of the dam is still gaining strength.
- In total, the casting of the dam alone required more than 600 thousand tons of cement and 3.44 million cubic meters. meters of filler. At the time of its completion, the Hoover Dam was considered the most massive man-made structure since the time of construction. To solve such a large-scale task, two concrete production plants were built.
Feat of the builders
The construction came at a difficult time, when there were many people in the country without work or a place to live. Construction literally saved many families, creating several thousand jobs. Despite the difficult conditions and the lack of basic amenities in the initial period, the flow of those in need of work did not dry out. People came with families and settled in tents near the construction site. 
Wages were hourly and started at 50 cents. The maximum bet was set at $1.25. At that time, this was decent money, desired by thousands of unemployed Americans. An average of 3-4 thousand people worked at the sites every day, but in addition to this extra work appeared in related industries. This rise was felt in neighboring states, where steel mills, mines, and factories were located. 
Under the terms of the contract, rules were negotiated between the contractor's representatives and the government to restrict hiring based on race. The employer's priority was professionals, military veterans, and white men and women. A small quota was agreed upon for Mexicans and African Americans, who were used as the cheapest labor force. It was strictly forbidden to accept people from Asia, especially the Chinese, for construction. The government had bad experience during the construction and restoration of San Francisco, where the diaspora of Chinese workers grew so large that it became the largest in the United States. 
A temporary camp was planned for construction workers, but contractors adjusted the schedule to try to increase construction speed and jobs. The village was built only a year later. The Big Six settled workers in permanent houses, imposing a number of prohibitions on residents. When the dam was built, the city was able to receive official status. 
It was not easy bread for builders. In the summer months, the temperature could remain at 40-50 degrees for a long time. The explorers and climbers risked their lives almost every shift. Officially, 114 deaths were registered, but in reality there were significantly more.
Significance of the project
The creation of the Hoover Dam cost America a huge sum at that time - $49 million. In just five years, a unique-scale construction project was completed. Thanks to the reservoir farms Nevada, California and Arizona today have the necessary water supply and can fully develop irrigated agriculture. Cities throughout the region received a cheap source of electricity, which gave impetus to industrial development and population growth. According to historians, the construction of the Hoover Dam is associated fast development Las Vegas is the gambling capital of America, which in a short period of time has transformed from a small provincial town into a pompous metropolis. 
Until 1949, the power plant and dam were considered the largest in the world. The Hoover Dam is owned by the US government and plays important role in maintaining the balance of electricity consumption in the western regions of the country. Automated system station control was introduced in 1991 and works perfectly even without operator participation. 
The Hoover Dam is attractive not only as a unique engineering structure. Its architectural value, which is associated with the name of the famous American architect Gordon Kaufman, was also noted. The external design of the dam, water intake towers, museum and memorial complex allowed the man-made structure to harmoniously fit into the panorama of the canyon. The dam is an extremely popular and recognizable object. It’s hard to imagine anyone who would refuse to take a photo against a backdrop of such breathtaking beauty. 
This is why companies public organizations They like to organize advertising or protest events in the area of the Hoover Dam. The Hoover Dam is very popular among filmmakers. She was saved by Superman and the hero of the film “Universal Soldier”; the hooligans Beavis and Butt-het tried to destroy her. The integrity of the concrete wall was encroached upon by the touching Homer Simpson and the formidable army of Transformers. And the creators computer games looked into the future of the Hoover Dam and came up with an idea for it new uniform existence after nuclear war and global apocalypse. 
Even after decades, with the advent of even larger projects, the dam continues to amaze. How much perseverance and courage it took to create and build such a unique engineering structure.
Hoover Dam (sometimes called Hoover Dam) is one of the tallest dams on the planet and one of the most powerful hydroelectric power plants in America.
It is located in the southwestern part of the country right on the border of the states of Nevada and Arizona, in the bed of the Colorado River, along which this border runs.
Hoover Dam on the map
- geographical coordinates 36.016065, -114.737411
- distance from the US capital Washington is about 3350 km in a straight line
- the nearest airport is Boulder City, approximately 14 km
- nearest international Airport McCarran, located in the famous Las Vegas, is 40 km west
- Hoover Dam is located at the outlet of Lake Mead, the largest man-made reservoir in the United States
The construction of the dam was necessary based on several factors.
The Colorado River, with its volatile nature, periodically flooded vast agricultural areas downstream. The construction of the dam was able to pacify the violent nature of the river and stabilize the water level in it. In addition, this could serve as an impetus for the development of irrigated agriculture in the region. The huge reservoir resulting from the construction of the dam will be able to satisfy the water needs of almost the entire southern part of California. And finally, the hydroelectric dam will benefit the population living in the surrounding area.
Hoover Dam in numbers
- Height – 221.4 meters
- Length – 379 meters
- Height above sea level – 376 meters
- Width at the base – 200 meters
- Width at the top – 14 meters
- Dam volume – 2,480,000 m3
- Weight more than 6,600,000 tons
- Spillway capacity – 11,000 m 3 /s
- The type is arched-gravity, in the shape of a semicircle directed towards Lake Mead, which allows for more efficient distribution of the water load. The water pressure in the lower part of the dam is about 220 tons per 1 square meter
This grandiose construction required a lot of research and approvals. Back at the beginning of the 20th century (in 1902), there was a search for opportunities to build a small dam on the Colorado River. But great success was not achieved. Then, in 1922, it was decided to create a commission, which included representatives of all states interested in the fair distribution of the river's water resources and the construction of a dam. The commission also included Herbert Hoover (he was not yet president at the time, but represented the federal government). The result of the commission’s work was the signing of the “Colorado River Convention” on November 22, 1922, which spelled out the relationships between entities claiming the resources of this river. But the construction of the dam did not begin immediately. It was only at the end of 1928 that John Calvin Coolidge (30th President of the United States) signed a bill authorizing construction. But the first financial injections into the project came only in July 1930, when Herbert Hoover himself was already the 31st President of the United States of America.
Hoover Dam construction process
According to the plan, construction was supposed to begin in 1931 and be completed in 1938, but the large-scale project was completed in 1936, 2 years earlier.
At that time, such a structure challenged the most advanced technologies. Conditions environment When the air temperature often reached 50 o C, the need to change the course of the Colorado River during construction and a host of other inconveniences posed serious challenges to engineers and designers. For example, it was impossible to simply pour concrete into a large formwork, since at ambient temperatures the entire structure would harden for about 125 years! In addition, the process of “setting” and “hardening” of concrete in such a large volume would inevitably lead to its cracking and destruction. Naturally, the developers were not satisfied with either the concrete hardening time or its quality at the end. Unique was accepted engineering solution– assemble the entire giant reinforced concrete structure from individual blocks.
By the way, we already know this solution from the buildings in ancient city in Peru. But, if in Sacsayhuaman the technology for fitting huge blocks is still unknown to science, then in the Hoover Dam it is not a secret.
Roughly speaking, the entire dam is assembled almost like a children's Lego set.
All blocks were same height, about one and a half meters, but the remaining dimensions varied depending on where the block was located. Maximum size block was 18 m 2 (in the lower part of the dam), and the minimum was 7.6 m 2 (in the upper part). Inside these blocks were laid steel pipes 1 inch in diameter (approximately 2.5 cm), through which circulated ice water. This made it possible to create conditions for proper hardening of concrete. The end result was very high quality concrete block, reinforced with pipes, which also connected the blocks to each other. By the way, the total length of these pipes was 937 km! After the block hardened, the pipes were filled with concrete and the next block was cast. In this way, a single monolithic structure was created. In 1995, studies were conducted that proved that the concrete of the Hoover Dam was still gaining strength. And such an indicator as compressive strength generally goes beyond the standard range for widespread concrete.
As you understand, the construction of such a grandiose project required significant human resources. Moreover, at first, practically nothing was provided for their accommodation. The workers lived in temporary camps and in fairly difficult conditions. As a result, on August 8, 1931, the builders went on strike, which was suppressed by force. Only in the spring of 1932 was housing built for workers in the town of Boulder City, and the unrest ceased.
Throughout the entire construction, it was prohibited in the town gambling and sale of alcohol.
Boulder City is the only city in Nevada, where gambling is still prohibited.
To change the course of the river and divert water from the work site, 4 tunnels were drilled in the mountains (two on each side of the river) with a diameter of just over 17 meters each and a total length of about five kilometers. The walls of the tunnels were filled with concrete 90 cm thick. Therefore, the effective diameter was reduced to 15 meters. At the end of the dam's construction, these tunnels were not filled up, that is, they are still active, which in turn gives the dam stability and reduces the load.
Water energy has found its application in hydroelectric power plants.
On October 26, 1936, the power plant produced its first electricity. Today, the total capacity of 17 generators is 2080 MW.
If all the spillways of the dam are opened, the energy of the falling water will be about 25,000,000 horsepower.
Unfortunately, throughout geodetic, research and construction work, deaths were common. In total, according to official data, 112 people died during the work. The sad statistics were discovered on December 20, 1922 by surveyor JG Tierney. He drowned while searching for a dam site in the Black Canyon of the Colorado River. Then there were accidents and several suicides. But there is something else interesting. Officially last death, registered during construction, dated December 20, 1935, that is, exactly 13 years after the first tragedy. But that's not all. The last person to die was named Patrick Tierney. He was the son of the same surveyor who took the fatal account.
In honor of all the people who died during construction, there is a memorial on the dam, the inscription on which reads “They died so that the deserts could bloom.”
Despite the tragedies and difficulties associated with the construction of the dam, the facility was commissioned ahead of schedule and in compliance with all technical regulations.
It is noteworthy that from 1933 until 1947 the dam was called “Boulder Dam”, as it was originally planned to be built in Boulder Canyon. The name was preserved even when the dam began to be built in the Black Canyon.
During the inauguration ceremony, it was proposed that the project be named "Hoover Dam" in honor of the then-current president. In the United States, there is indeed a tradition of naming a large dam after the president in office at the time of its construction. And in February 1931, Congress officially approved this name.
The adventures with the name did not stop there. In 1932, Franklin Roosevelt was elected president, and his administration decided to rename the dam back to Boulder Dam. And although no official decision was made, Hoover's name disappeared from all documents, both official and tourist brochures.
In 1947, 2 years after Roosevelt's death, a bill was introduced in the Senate to return the dam to the name of Herbert Hoover. It was approved by the Senate and signed by the President. And now this US landmark is known to the whole world as the “Hoover Dam”.
The top of the dam is a bridge connecting the banks of the Colorado River. After the tragedy of September 11, 2001, passage through the dam was limited, and in 2010, a backup bridge was erected at a distance of half a kilometer from the dam, which significantly reduced the load on the dam and increased its safety.
Such a colossal structure invariably attracts tourists, so you can take a tour here and learn a lot of interesting things.
- For some time, the states in which the Colorado River flows could not come to a common decision on the issue of building a dam. They feared that the river’s resources would be distributed unevenly and “unfairly,” but after negotiating, they finally came to an agreement. Important influence Herber Hoover (he was not yet president at the time, but represented the federal government) influenced the decision. He managed to convince all participants of the feasibility of building a dam and fair distribution of natural resources. Subsequently, historians called this fact “Hoover’s compromise.”
- Thousands of people worked simultaneously on the construction of the dam, but the maximum was recorded in June 1934. At that time, 5,218 people took part in the construction. In total, about 21,000 people worked on the project
- the dam is managed by the US Bureau of Reclamation, which in turn is a division of the US Department of the Interior
- Since 1981, the Hoover Dam has been included in National list historical places USA
- the construction of the dam took 2,480,000 cubic meters of concrete. This would be enough to build a high-quality two-lane highway from San Francisco to New York, which is about 4,700 km. The thickness of the coating would be 20 cm and the width would be about 5 meters
- the first concrete was poured into the dam on June 6, 1933, and the last on May 29, 1935
- monthly average wage employees was $500,000
- About one million tourists visit Hoover Dam every year
- the project cost the US budget $49 million
- from 1939 to 1949, the Hoover Dam hydroelectric power plant was the largest in the world
Hoover Dam photo
The dam lies on the Arizona-Nevada border in the Black Canyon on the Colorado River, and was named after President Herbert Hoover by Franklin D. Roosevelt in 1935. September 30, 2011 was the 76th anniversary of the dam's naming. The concrete arch-gravity structure, 221 meters high, was built over five years, from 1931 to 1936. This collection contains photographs showing the construction process.
(Total 54 photos)
1. Night shot of Hoover Dam, 1983. (AP Photo/Steve McPeak)
2. The site where work will soon begin on one of the most ambitious construction projects in US history, September 19, 1930. About 11 km from Las Vegas, Nevada. When completed, the dam will supply electricity to six states. Its cost was estimated before construction began at about $165,000,000. (AP Photo)
3. This site will contain a reservoir with an area of 227 square miles. Reclamation engineer Elmer L. Chapman points to the hills that will be flooded once construction is completed. Nevada, August 24, 1932. The flat-topped mountain in the center of the frame will become an island, rising just 14 meters above the water. (AP Photo)
4. This aerial photograph taken by Fairchild shows the site of the future dam on March 4, 1931. The lowest contract price was offered by Six Companies Inc. from San Francisco, California. The amount was $48,890,995.50. (AP Photo/Fairfield Aerial Surveys)
5. People at the opening ceremony of construction in Nevada, September 17, 1930. Secretary Ray Lyman Wilbur made the announcement that the dam would be renamed from Boulder Dam to Hoover Dam. (AP Photo)
6. Secretary Ray Lyman Wilbur drives a silver spike into a tie on the railroad tracks connecting Las Vegas and the construction site, September 19, 1930. This signaled the official start of work on the $165 billion project. From left to right: Congressman William Eaton of Colorado, Senator Kay Pittyman of Nevada, Secretary Wilbur and Senator Samuel Shortridge. (AP Photo)
7. A post office opens in Boulder City, a city of construction workers. Bureau of Reclamation employees gathered at the opening to congratulate postman J.L. Finney, April 15, 1931. To the left: V.R. Armstrong, head of United Pacific, R.F. Walter, Chief Engineer of the Bureau of Reclamation, Carpenter of Six Company Inc., Postman Finney, Dr. Elwood Mead, Commissioner of the Reclamation Commission, and P.W. Dent, Dr. Meade's assistant. (AP Photo)
8. Main Street Boulder City, Nevada, August 24, 1932. The city was built for workers involved in the construction of the dam at a cost of $2 million (AP Photo)
9. Top view of the Hoover Dam construction site. The site is directly above the power plant, and is part of the Nevada-Arizona Highway, which will run along the top of the dam. August 24, 1932. In addition, during construction the largest man-made lake in the world will be created. (AP Photo)
10. Photo showing the mountainous terrain along the banks of the Colorado River. There is no water in the riverbed because it was redirected to underground tunnels during construction, January 12, 1923. This is where the Hoover Dam will be built. Water emerges from underground tunnels at the bottom of the image. (AP Photo)
11. A steel container with a capacity of 8 cubic meters pours the first batch of solution into the foundation of the Hoover Dam at the bottom of the Black Canyon, Nevada, June 9, 1933. The formwork has three walls, and the fourth is formed by the adjacent canyon rock. (AP Photo)
12. Inside one of the canyons that will divert the Colorado River. Nevada, April 18, 1932. Project on early stage construction. (AP Photo)
13. A machine called the Big Drill was developed to speed up work on tunnels. It is mounted on the back of a 10-ton truck, and 24 to 30 jackhammers mounted on it can work simultaneously
14. Construction site of the Hoover Dam on the border of Arizona and Nevada. Concrete lining of spillway walls. A bucket with two cubic meters of solution is lifted onto the crane. June 1933. (Library of Congress Prints and Photographs Division Washington, D.C.)
15. A view from below upstream of Black Canyon shows the construction site of the Hoover Dam. Nevada, date unknown. At the bottom of the photo, dozens of trucks are visible delivering materials for the solution. (AP Photo)
16. The dam was built from rectangular columns with a cross-section from 20 (on the outer part) to 8 (on the inner) square meters. The dam consists of 215 concrete blocks stacked on top of each other. Adjacent columns are connected to each other by a system of vertical lintels at radial joints and horizontal lintels at peripheral joints (think giant Lego). No more than one and a half meters of solution was poured into one block in 72 hours. After it hardened, a more liquid solution was poured into the spaces between the columns to create a monolithic structure. (Department of the Interior, Bureau of Reclamation)
17. This Bureau of Reclamation photo shows a half-finished dam. Work is ongoing day and night, and construction is several months ahead of schedule. Construction of foundations for power plants can be seen at the base of the dam. The dark line in the center of the dam is a void, specially left to facilitate the hardening of the solution. (AP Photo)
18. Construction continues. Trucks are moving 50 tons of dirt per minute to divert the Colorado River from the dam site to underground tunnels. November 15, 1932. (AP Photo)
19. View from above downstream. Numerous concrete structures are rising from the bottom of the canyon, which will become the foundation of the dam. Nevada, August 12, 1933. 6,000 cubic meters of solution are poured into molds per day. (AP Photo)
20. View of one of the Hoover Dam spillway towers, August 9, 1934. The towers, two on each side, will rise 120 meters. (AP Photo)
21. Construction of the Hoover Dam in Nevada, near Las Vegas, continues, January 9, 1932. (AP Photo)
23. The three-million-pound gate above Tunnel 4 is ready to close, February 1, 1935. Closing the gates in the underground tunnels will return the Colorado River to its channel and fill the huge reservoir. The photo was taken shortly before the gates closed. (AP Photo)
24. Photo of the canyon shows temporary suspension bridge and tunnel openings to drain water away from the construction site, March 12, 1932. (AP Photo)
25. Aerial photograph of Hoover Dam, July 16, 1935. The soon-to-be-opened road will provide quick access between Las Vegas, Nevada, and Kingman, Arizona. The spillway towers are visible on the other side of the dam. (AP Photo)
26. Rare view of the outer wall of the dam, May 1935. (Bureau of Reclamation, United States)
27. Three workers paint metal structures on the wall of the Hoover Dam spillway. The photo 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 construction of the Hoover Dam. The elevation is 500 feet of the design 730 above the canyon floor. August 28, 1934. (AP Photo)
29. More than 200 meters above the Colorado River, workers complete construction of the Hoover Dam on August 12, 1935. (AP Photo)
30. 3500 horsepower generator in Boulder City, Nevada, September 10, 1936. In a month, generators with a capacity of 115,000 horsepower will provide electricity to cities in southern California, 400 km away. (AP Photo)
31. People at the ceremony to launch the power plant at the Hoover Dam. With the push of a button in Washington, President Roosevelt fired up the first 3,500-horsepower turbine on September 11, 1936. (AP Photo)
32. Hoover Dam, photo from the series " National parks and Monuments" by photographer Ansel Adams containing photographs from 1933-1942. (U.S. National Archives and Records Administration)
33. Aerial shot of the dam. (AP Photo)
34. President Roosevelt at the Hoover Dam, September 30, 1935, the day it was renamed. . (AP Photo)
35. President Roosevelt at Hoover Dam, September 30, 1935. Also pictured are Bureau of Reclamation representative Walker Young (left) and military adviser to the president (right)
36. Aerial photo of Hoover Dam, March 13, 1936. Upstream from the dam, part of Mead Reservoir is visible. The dam releases tens of thousands of liters of water per second. The spillway towers are visible above the dam. (AP Photo)
37. Switchgear at Hoover Dam against the desert night sky, April 27, 1937. Electricity from fifteen 115,000 horsepower generators and two 55,000 horsepower generators comes here and is then sent along the main power line to Los Angeles. (AP Photo/Department of the Interior)
38. Huge spillway towers at Hoover Dam, April 14, 1938. The water that drives the generators at the bottom of the 221-meter dam is fed to the turbines through these towers. A recreation area was established on the banks of the reservoir. (AP Photo)
39. Turbine room of the power plant at the Hoover Dam. On February 7, 1939, these 82,500 kVA generators were the most powerful in the world. The generators produced 130,000,000 kilowatt-hours of energy per month. The Bureau of Reclamation, which built the dam, received $3,297,289 over two years. Then about a third of the possible amount of energy was generated. (AP Photo)
40. Sheriff's Aviation Unit planes patrol over Lake Mead and Hoover Dam, July 13, 1948. The unit patrols an 8,000-square-mile area, one of the most desolate areas in the country, searching for lost travelers, coming to the aid of drivers whose cars are disabled and conducting rescue operations when planes crash in the desert. (AP Photo)
42. Dancers of the Rhythmettes ballet from Las Vegas at the Hoover Dam, June 8, 1957. The girls have given concerts in many cities in the six years since the creation of the ballet. (AP Photo/V)
43. The majestic structure of the Hoover Dam, May 11, 1953, one of the engineering triumphs of the century. Reservoir Mead, the largest man-made lake in the world, has become a favorite destination for fishermen and boaters. (AP Photo)
44. This photo provided by the Union Pacific Railroad shows one of the world's largest hydroelectric dams, the Hoover Dam, on February 26, 1957. Lake Mead, located above the dam, is a great place for fishing, boating and other water activities throughout the summer season. (AP Photo/Union Pacific Railroad)
45. Daredevil Steve McPeak above the Hoover Dam during a protest against the policies of the Reagan administration, December 8, 1982. (AP Photo/Frank Walters)
46. Steve McPeak with Hoover Dam guards hours before he was persuaded to fall from his ropes over the Colorado River on December 9, 1982. McPeak spent three days and two nights on the ropes, thus protesting the policies of the Reagan administration. (AP Photo/Scott Henry)
47. Hoover Dam is a concrete arch-gravity dam in the Black Canyon on the Colorado River, on the border of Nevada and Arizona. It was built between 1931 and 1936 during the Great Depression. Thousands of workers were involved in the construction and more than a hundred died as a result of accidents. The dam is named after President Herbert Hoover.
50. Millions of liters of water pour through the gate of the Hoover Dam, February 26, 2004. On this day, the strength of the pipes in the lock was tested. (AP Photo/Joe Cavaretta)53. Aerial photo of Hoover Dam and bridge under construction, June 12, 2009, Arizona. (Photo by Ethan Miller/Getty Images)
54. Mike O'Callahan-Pat Tillman Bridge near Hoover Dam, October 26, 2010. The bridge is more than 600 meters long and is located 280 meters above the Colorado River. A $240 million project would create an additional crossing over the Colorado on the Nevada Highway. -Arizona Construction began in 2003 and the bridge opened to traffic on October 19, 2010. (Photo by Ethan Miller/Getty Images)
