Hoover Dam
Hoover Dam from the air
Official name	Hoover Dam
Impounds	Colorado River
Creates	Lake Mead
Locale	Nevada-Arizona USA
Maintained by	U.S. Bureau of Reclamation
Length	1244 ft (379 m)
Height	726. The Colorado River (' Aha Kwahwat in Mojave) is a River in the southwestern United States and northwestern Mexico, approximately Lake Mead is the largest man-made Lake and Reservoir in the United States. Nevada ( is a state located in the western region of the United States of America. The State of Arizona ( is a state located in the southwestern region of the United States. The United States of America —commonly referred to as the The Bureau of Reclamation (formerly the United States Reclamation Service) is an agency under the U 4 ft (221 m)
Construction began	1931
Opening date	1936
Geographical Data
Coordinates	36°0′56″N 114°44′16″W / 36.01556, -114.73778Coordinates: 36°0′56″N 114°44′16″W / 36.01556, -114.73778

Hoover Dam
(U.S. National Historic Landmark)
Hoover Dam by Ansel Adams
Nearest city:	Boulder City, Nevada
Built/Founded:	1933
Architect:	Six Companies,Inc. A geographic coordinate system enables every location on the Earth to be specified in three coordinates using mainly a spherical coordinate system. A geographic coordinate system enables every location on the Earth to be specified in three coordinates using mainly a spherical coordinate system. The United States of America —commonly referred to as the A National Historic Landmark (NHL is a Building, site, Structure, Object, or District, that is officially recognized by the Ansel Easton Adams (February 20 1902 – April 22 1984 was a legendary American Photographer and Environmentalist, best known for his Black-and-white Boulder City is a city in Clark County, Nevada, United States.
Architectural style(s):	Art Deco
Designated as NHL:	August 20, 1985[1]
Added to NRHP:	April 08, 1981[2]
NRHP Reference#:	81000382
MPS:	Vehicular Bridges in Arizona MPS (AD)
Governing body:	BUREAU OF RECLAMATION

Hoover Dam, also known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Arizona and Nevada. A National Historic Landmark (NHL is a Building, site, Structure, Object, or District, that is officially recognized by the Events 636 - Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of Syria and Palestine Year 1985 ( MCMLXXXV) was a Common year starting on Tuesday (link displays 1985 Gregorian calendar) The National Register of Historic Places (NRHP is the United States government's official list of districts sites buildings structures and objects deemed worthy of Events 217 - Roman Emperor Caracalla is Assassinated (and succeeded by his Praetorian Year 1981 ( MCMLXXXI) was a Common year starting on Thursday (link displays the 1981 The National Register of Historic Places (NRHP is the United States government's official list of districts sites buildings structures and objects deemed worthy of Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag An arch-gravity dam, such as the Hoover Dam, is a dam with the characteristics of both an Arch dam and a Gravity dam. The Black Canyon is the Canyon where Hoover Dam was built It is located on the Colorado River in the United States. The Colorado River (' Aha Kwahwat in Mojave) is a River in the southwestern United States and northwestern Mexico, approximately Borders define geographic boundaries of political entities or legal jurisdictions such as Governments States or subnational administrative The United States of America —commonly referred to as the A US state is any one of the fifty subnational entities of the United States of America that share Sovereignty with the federal government The State of Arizona ( is a state located in the southwestern region of the United States. Nevada ( is a state located in the western region of the United States of America. When completed in 1935, it was both the world's largest electric power producing facility and the world's largest concrete structure. It was surpassed in both respects by the Grand Coulee Dam in 1945. Grand Coulee Dam is a Hydroelectric Gravity dam on the Columbia River in the U It is currently the world's 34th largest hydroelectric generating station. ^[3]

The dam, located 30 miles (48 km) southeast of Las Vegas, is named after Herbert Hoover, who played an instrumental role in its construction, first as Secretary of Commerce and then later as President of the United States. Las Vegas ( Spanish: "The Meadows" is the most populous City in the state of Nevada, the seat of Clark County, and an internationally Herbert Clark Hoover (August 10 1874 &ndash October 20 1964 was the thirty-first President of the United States (1929–1933 The United States Secretary of Commerce is the head of the United States Department of Commerce concerned with business and industry the Department states its mission to The President of the United States is the Head of state and Head of government of the United States and is the highest political official in United States by Construction began in 1931 and was completed in 1935, more than two years ahead of schedule. The dam and the power plant are operated by the Bureau of Reclamation of the U.S. Department of the Interior. The Bureau of Reclamation (formerly the United States Reclamation Service) is an agency under the U The United States Department of the Interior ( DOI) is a Cabinet department of the United States government that manages and conserves most federally Listed on the National Register of Historic Places in 1981, Hoover Dam was designated a National Historic Landmark in 1985. The National Register of Historic Places (NRHP is the United States government's official list of districts sites buildings structures and objects deemed worthy of A National Historic Landmark (NHL is a Building, site, Structure, Object, or District, that is officially recognized by the ^[1][4]

Lake Mead is the reservoir created behind the dam, named after Elwood Mead, who oversaw the construction of the dam. Lake Mead is the largest man-made Lake and Reservoir in the United States. Elwood Mead ( January 16, 1858 in Patriot Indiana &ndash January 26, 1936) was a professor politician and engineer who headed the

Planning and agreements

A commission was formed in 1922 with a representative from each of the Basin states and one from the Federal Government. The federal representative was Herbert Hoover, then Secretary of Commerce under President Warren Harding. Herbert Clark Hoover (August 10 1874 &ndash October 20 1964 was the thirty-first President of the United States (1929–1933 Warren Gamaliel Harding (November 2 1865 August 2 1923 was the twenty-ninth President of the United States, serving from 1921 until his death from a heart attack aged In January 1922, Hoover met with the state governors of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming to work out an equitable arrangement for apportioning the waters of the Colorado River for their states' use. The resulting Colorado River Compact, signed on November 24, 1922, split the river basin into upper and lower halves with the states within each region deciding how the water would be divided. The Colorado River Compact is a 1922 agreement among seven US Events 380 - Theodosius I makes his adventus, or formal Year 1922 ( MCMXXII) was a Common year starting on Sunday of the Gregorian calendar. This agreement, known as the Hoover Compromise, paved the way for the Boulder Dam Project. It was built to help keep the silt and sediment out of the Colorado River.

Herbert Hoover

The first attempt to gain Congressional approval for construction of Boulder Dam came in 1922 with the introduction of two bills in the House of Representatives and the Senate. Herbert Clark Hoover (August 10 1874 &ndash October 20 1964 was the thirty-first President of the United States (1929–1933 The bills were introduced by Congressman Phil D. Swing and Senator Hiram W. Johnson and were known as the Swing-Johnson bills. Philip David "Phil" Swing ( November 30, 1884 &ndash August 8, 1963) is a former American Hiram Warren Johnson ( September 2, 1866 August 6, 1945) was a leading American progressive and later Isolationist The bills failed to come up for a vote and were subsequently reintroduced several times. In December 1928, both the House and the Senate finally approved the bill and sent it to the President for approval. On December 21, 1928, President Calvin Coolidge signed the bill approving the Boulder Canyon Project. Events 69 - The end of the Year of the four emperors: Following Galba, Otho and Vitellius, Vespasian Year 1928 ( MCMXXVIII) was a Leap year starting on Sunday (link will display full calendar of the Gregorian calendar. John Calvin Coolidge Jr (July 4 1872 January 5 1933 was the thirtieth President of the United States (1923–1929 The initial appropriation for construction was made in July 1930, by which time Herbert Hoover had become President. Herbert Clark Hoover (August 10 1874 &ndash October 20 1964 was the thirty-first President of the United States (1929–1933

Early plans called for the dam to be built in Boulder Canyon, so the project was known as the Boulder Canyon Project. The dam site was eventually moved downstream eight miles to Black Canyon, but the project name remained the same.

Contractors

The contract to make the Boulder Dam was awarded to Six Companies, Inc. on March 11, 1931,^[5] a joint venture of Morrison-Knudsen Company of Boise, Idaho; Utah Construction Company of Ogden, Utah; Pacific Bridge Company of Portland, Oregon; Henry J. Kaiser & W. Six companies can also refer to the Chinese Six Companies Six Companies Inc Events 1425 BC - Thutmose III, Pharaoh of Egypt, dies (according to the Low Chronology of the 18th Dynasty Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Washington Group International was an American corporation which provided integrated engineering construction and management services to businesses and governments around the world Boise (ˈbɔɪsi is the capital and most populous city of the U Ucc-logo-2png|thumb|200px|Utah Construction Logo from 1959 - 1970]] Utah Construction Company was a construction company founded by Edmund Orson Wattis Jr, Warren L Ogden is a city in and the County seat of Weber County, Utah, United States. Portland is a city located in the Northwestern United States, near the Confluence of the Willamette and Columbia rivers Henry John Kaiser ( May 9, 1882 — August 24, 1967) was an American Industrialist who became known as the father of modern American A. Bechtel Company of Oakland, California; MacDonald & Kahn Ltd. Bechtel Corporation ( Bechtel Group) is the largest Engineering company in the United States, ranking as the 9th-largest privately owned company in the Oakland (ˈoʊklənd founded in 1852 is the eighth-largest city in the U of Los Angeles; and the J. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West F. Shea Company of Portland, Oregon. The chief executive of Six Companies, Frank Crowe, had previously invented many of the techniques used to build the dam. Six companies can also refer to the Chinese Six Companies Six Companies Inc Francis Trenholm Crowe (1882&ndash1946 was the chief engineer of the Hoover Dam.

During the concrete-pouring and curing portion of construction, it was necessary to circulate refrigerated water through tubes in the concrete. This was to remove the heat generated by the chemical reactions that solidify the concrete, since the setting and curing of the concrete was calculated to take about 125 years. Six Companies, Inc. , did much of this work, but it discovered that such a large refrigeration project was beyond its expertise. Hence, the Union Carbide Corporation was contracted to assist with the refrigeration needs. Union Carbide Corporation ( Union Carbide) is one of the oldest chemical and polymers companies in the United States, currently employing more than 3800 people

Six Companies, Inc. was contracted to build a new town called Boulder City for workers, but the construction schedule for the dam was accelerated in order to create more jobs in response to the onset of the Great Depression, and the town was not ready when the first dam workers arrived at the site in early 1931. Boulder City is a city in Clark County, Nevada, United States. During the first summer of construction, workers and their families were housed in temporary camps like Ragtown while work on the town progressed. Discontent with Ragtown and dangerous working conditions at the dam site led to a strike on August 8, 1931. Events 1220 - Sweden is defeated by Estonian tribes in the Battle of Lihula. Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Six Companies responded by sending in strike-breakers with guns and clubs, and the strike was soon quelled. But the discontent prompted the authorities to speed up the construction of Boulder City, and by the spring of 1932 Ragtown had been deserted. ^[6] Gambling, drinking and prostitution were not permitted in Boulder City during construction. To this day Boulder City is the only location in Nevada not to allow gambling, and the sale of alcohol was illegal until 1969.

While working in the tunnels, many workers suffered from the carbon monoxide generated by the machinery there. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. The contractors claimed that the sickness was pneumonia and was not their responsibility. Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal Some of the workers sickened and died because of the so-called "pneumonia". Most are uncounted on the official death list. In a court case, one of the claimants (Ed Kraus) said that the poisoning had resulted in his impotence. This was disproved after a prostitute in the pay of the contractors gave evidence. The jury failed to reach a verdict as a result, and the claim was lost. ^[7]

Construction

Groundworks

Hoover Dam Architectural Plans

Overview Of Dam Mechanisms

To protect the construction site from flooding, two cofferdams were constructed. Construction A cofferdam (also called coffer) is an enclosure beneath the water constructed to allow water to be displaced by air for the purpose of creating a dry Construction of the upper cofferdam began in September 1932, even though the river had not yet been diverted. A temporary horseshoe-shaped dike protected the cofferdam on the Nevada side of the river. After the Arizona tunnels were completed, and the river diverted, the work was completed much faster. Once the coffer dams were in place and the construction site dewatered, excavation for the dam foundation began. For the dam to rest on solid rock, it was necessary to remove all loose material until solid rock was reached. Work on the foundation excavations was completed in June 1933. During excavations for the foundation, approximately 1,500,000 yd³ (1,150,000 m³) of material was removed, including material removed in canyon wall stripping operations.

River diversion

To divert the river's flow around the construction site, four diversion tunnels were driven through the canyon walls, two on the Nevada side and two on the Arizona side. These tunnels were 56 feet (17. 07 m) in diameter. Their combined length was nearly 16,000 feet (4877 m, more than three miles). Tunneling began at the lower portals of the Nevada tunnels in May 1931. Shortly after, work began on two similar tunnels in the Arizona canyon wall. In March 1932, work began on lining the tunnels with concrete. First the base or invert was poured. Gantry cranes, running on rails through the entire length of each tunnel were used to place the concrete. Both overhead travelling cranes and gantry cranes are types of crane which lift objects by a hoist which is fitted in a trolley and can move Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag The sidewalls were poured next. Movable sections of steel forms were used for the sidewalls. Finally, using pneumatic guns, the overheads were filled in. The concrete lining is 3 feet (914. 4 mm) thick, reducing the finished tunnel diameter to 50 ft (15. 24 m).

Following the completion of the dam, the entrances to the two outer diversion tunnels were sealed at the opening and half way through the tunnels with large concrete plugs. The downstream half of the tunnels following the inner plugs are now the main body of the spillway tunnels. The spillways can be seen directly above the outer diversion tunnels. They drop sharply from their entrance point and merge directly into the old diversion tunnels.

Two intake towers on the Arizona side. The State of Arizona ( is a state located in the southwestern region of the United States.

The two inner diversion tunnels have two concrete plugs in them. One is roughly half way along their length, and the other is around 75% of the way along their length. The section sandwiched between two concrete plugs is used as part of the tunnel which water travels along, to journey from the outermost intake towers and the generators. The two innermost intake towers have separate tunnels.

The large spillway tunnels have only been used three times in the history of the dam; the first was during the second half of 1941 for testing. The second was for about six weeks during the summer of 1983, when record precipitation and snow-melt in the Colorado River basin drained into Lake Mead, and the third in 1999, again with heavy precipitation that filled Lake Mead. ^[8]

Rock clearance

Before construction began on the dam itself it was necessary to remove loose rock from the canyon walls. The design of the dam is the arch and gravity type. The load of the water in the storage reservior is resisted by both the gravity/mass of the dam, and by the arch of the dam pressing against and into the side walls of Black Canyon. Therefore, the two vertical foundations for each of the arch walls (the Nevada side and Arizona side) had to be founded on sound "virgin" rock; free of cracks and the weathering that the surface rock of the canyon walls had from thousands of years of weathering and exposure.

The men who removed this rock were called "high-scalers. " While suspended from the top of the canyon with ropes high-scalers climbed down the canyon walls and removed the loose rock with jackhammers and dynamite. A pneumatic drill or jackhammer is a portable percussive Drill powered by Compressed air. Dynamite is an explosive based on the explosive potential of Nitroglycerin, initially using Diatomaceous earth (kieselgur US Spelling kieselguhr

Concrete pouring

The first concrete was placed into the dam on June 6, 1933. Events 1508 - Maximilian I Holy Roman Emperor, is defeated in Friulia by Venetian forces; he is forced to sign a three-year Year 1933 ( MCMXXXIII) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar. Since no structure of the magnitude of the Hoover Dam had been constructed, many of the procedures used in construction of the dam were untried. Since concrete heats up and contracts as it cures, uneven cooling and contraction of the concrete posed a serious problem. The Bureau of Reclamation engineers calculated that if the dam were built in a single continuous pour, the concrete would have taken 125 years to cool to ambient temperature. The Bureau of Reclamation (formerly the United States Reclamation Service) is an agency under the U The resulting stresses would have caused the dam to crack and crumble. ^[9] To solve this problem the dam was built in a series of interlocking trapezoidal columns. Each pour was no more than six inches deep. Because of this depth it is extremely unlikely that construction workers were accidentally buried alive in the concrete, contrary to popular folklore. ^[10] To further cool the concrete each form contained cooling coils of 1 inch (25. 4 mm) thin-walled steel pipe. River water was circulated through these pipes to help dissipate the heat from the curing concrete. After this, chilled water from a refrigeration plant on the lower cofferdam was circulated through the coils to further cool the concrete. After each layer had sufficiently cooled the cooling coils were cut off and pressure grouted by pneumatic grout guns. Pneumatics, Pressurized gas to affect mechanical motion Pneumatic power is used in Industry, where it is common to have factory units plumbed for Compressed Grout is a Construction material used to embed Rebars in Masonry walls connect sections of pre-cast Concrete, fill voids and seal joints (like The concrete is still curing and gaining in strength as time goes on. ^[11]

There is enough concrete in the dam to pave a two-lane highway from San Francisco to New York ^[12]. The City and County of San Francisco is the fourth most populous city New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous

Construction deaths

There were 112 deaths associated with the construction of the dam. ^[10][13] There are different accounts as to how many people died while working on the dam and who was the first and last to die. A popular story holds that the first person to die in the construction of Hoover Dam was J. G. Tierney, a surveyor who drowned while looking for an ideal spot for the dam. Coincidentally, his son, Patrick W. Tierney, was the last man to die working on the dam, 13 years to the day later. ^[10][13] 96 of the deaths occurred during construction at the site. However, another surveyor died prior while surveying a potential location for the dam and these statistics do not include other incidental and coincidental (heat stroke, heart failure, etc) deaths during construction. ^[10]

Power plant

The hydroelectric generators at Hoover dam

The seventeen turbine-generators at this powerhouse generate a maximum of 2,074 megawatts of hydroelectric power. A turbine is a rotary Engine that extracts Energy from a Fluid flow The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second.

Excavation for the powerhouse was carried out simultaneously with the excavation for the dam foundation and abutments. Excavation for the U-shaped structure located at the downstream toe of the dam was completed in late 1933 with the first concrete placed in November 1933.

Generators at the Dam's Hoover Powerplant began transmission of electricity from the Colorado River to Los Angeles, California 266 miles (428 km) away on October 26, 1936. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West Events 740 - An Earthquake strikes Constantinople, causing much damage and death Year 1936 ( MCMXXXVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian calendar. Additional generating units were added through 1961.

Water flowing from Lake Mead through the gradually-narrowing penstocks to the powerhouse reaches a speed of about 85 miles per hour (137 km/h) by the time it reaches the turbines. The entire flow of the Colorado River passes through the turbines. The spillways are rarely used.

Hydroelectric power plants have the ability to vary the amount of power generated, depending on the demand. Hydroelectricity is electricity generated by Hydropower, ie the production of power through use of the gravitational force of falling water A load following power plant is a Power plant that adjusts its power output as demand for Electricity fluctuates throughout the day Steam turbine power plants are not as easily "throttled" because of the amount of thermodynamic inertia contained in their systems. A steam turbine is a mechanical device that extracts Thermal energy from pressurized Steam, and converts it into useful mechanical work

Architectural style

The dam crosses the border between two time zones, the Pacific Time Zone and the Mountain Time Zone

The initial plans for the finished facade of both the dam and the power plant consisted of a simple, unadorned wall of concrete topped with a Gothic-inspired balustrade and a powerhouse that looked like little more than an industrial warehouse. The Pacific Time Zone observes Standard time by subtracting eight hours from Coordinated Universal Time ( UTC-8) The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time ( UTC-7) during the shortest days of autumn A facade or façade (fəˈsɑːd is generally one side of the exterior of a Building, especially the front but also sometimes the sides and rear See also Gothic art Gothic architecture is a style of Architecture which flourished during the high and late medieval period. A baluster (according to OED derived through the French balustre, from Italian balaustro, from balaustra, "pomegranate flower" This initial design was criticized by many as being too plain and unremarkable for a project of such immense scale, so Los Angeles-based architect Gordon B. Kaufmann was brought in to redesign the exteriors. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West Gordon Kaufmann (1888-1949 was an English born American architect mostly known for his work on the Hoover Dam. Kaufmann greatly streamlined the buildings, and applied an elegant Art Deco style to the entire project, with sculptured turrets rising seamlessly from the dam face and clock faces on the intake towers set for Nevada and Arizona time, in the Pacific and Mountain time zones respectively (although because Arizona does not observe daylight saving time, the two clocks show the same time throughout much of the year). Art Deco was a popular international design movement from 1925 until 1939 affecting the decorative arts such as Architecture, Interior design, and Industrial The Pacific Time Zone observes Standard time by subtracting eight hours from Coordinated Universal Time ( UTC-8) The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time ( UTC-7) during the shortest days of autumn Daylight saving time ( DST

Use for road transport

U. S. Highway 93 on Hoover Dam

Hoover Dam serves as a crossing for U.S. Route 93. US Route 93 is a major north-south United States highway in the Western United States. The two lane section of road approaching the dam is narrow, has several dangerous hairpin turns, and is subject to rock slides. Haarspeldbochtjpg|thumb|Hairpin turn on the Mont Ventoux in France]]A hairpin turn (also hairpin bend hairpin corner etc A landslide is a geological phenomenon which includes a wide range of ground movement such as rock falls deep failure of slopes and shallow debris flows which can occur

Additionally, in the wake of the September 11, 2001 terrorist attacks there are significant security concerns. Because of the attack the Hoover Dam Bypass project was expedited. Hoover Dam Bypass refers to the construction of the Mike O'Callaghan-Pat Tillman Memorial Bridge and connecting roads for a new route across the Colorado River for The Hoover Dam Bypass is scheduled to be completed in 2010 and will divert US 93 traffic 1,500 feet downstream of the dam. Hoover Dam Bypass refers to the construction of the Mike O'Callaghan-Pat Tillman Memorial Bridge and connecting roads for a new route across the Colorado River for ^[14] The bypass will include a composite steel and concrete arch bridge, tentatively named the Mike O'Callaghan-Pat Tillman Memorial Bridge. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag Donal Neil "Mike" O'Callaghan ( September 10, 1929 March 5, 2004) was the governor of the U Patrick Daniel Tillman ( November 6, 1976   – April 22, 2004) was an American football player who left his professional sports

Traffic across Hoover Dam is now restricted. Some types of vehicles are inspected prior to crossing the dam while semi-trailer trucks, buses carrying luggage, and enclosed-box trucks over 40 feet are not allowed on the bridge at all. truckcartransporterarp750pixjpg|thumb|right|A tractor with an auto-transport Semi-trailer. ^[15] This traffic is diverted south to a Colorado River crossing close to Laughlin, Nevada. Laughlin is a Census-designated place (CDP in Clark County, Nevada, United States.

Power distribution

One of two "Winged Figures of the Republic" by Oskar J. W. Hansen, part of the monument of dedication on the Nevada side of the dam. ^[16]

The Bureau of Reclamation reports that the energy generated is allocated as follows:^[17]

Statistics

Downstream from Hoover Dam, showing the river, power stations, and power lines.

Aerial shot of Lake Mead and Hoover Dam showing the high-water mark of the 1983 flood season along the shore

• Construction period: April 20, 1931 – March 1, 1936
• Construction cost: $49 million ($676 million adjusted for inflation)
• Deaths attributed to construction: 112; 96 of them at the construction site^[10][13][18]
• Dam height: 726. Events 1303 - The University of Rome La Sapienza is instituted by Pope Boniface VIII. Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Events 86 BC - Lucius Cornelius Sulla, at the head of a Roman Republic army enters in Athens, removing the Tyrant Year 1936 ( MCMXXXVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian calendar. In economics inflation or price inflation is a rise in the general level of prices of goods and services over a period of time 4 ft (221.4 m), second highest dam in the United States. The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International (Only the Oroville Dam is taller)
• Dam length: 1244 ft (379.2 m)
• Dam thickness: 660 ft (200 m) at its base; 45 ft (15 m) thick at its crest. Oroville Dam is on the Feather River above the city of Oroville in Butte County, California. The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International
• Concrete: 4. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag 36 million yd³ (3.33 million m³)
• Electric Power produced by the water turbines: 2,080 megawatts
• Traffic across the dam: 13,000 to 16,000 people each day, according to the Federal Highway Administration
• Lake Mead (full pool)^[19]
  • area: 157,900 acres (639 km²), backing up 110 miles (177 km) behind the dam. A cubic yard is an Imperial / US customary (non- SI non- metric) unit of Volume, used in the United States, Canada and To help compare different Orders of magnitudes this page lists Volumes between 1 million and 10 million cubic Metres Volumes smaller CM3 redirects here If you were looking for the 3rd game in the Cooking Mama series abbreviated as CM3 see here. A water turbine is a rotary Engine that takes energy from moving water The Federal Highway Administration ( FHWA) is a division of the United States Department of Transportation that specializes in Highway transportation Lake Mead is the largest man-made Lake and Reservoir in the United States.
  • volume: 28,537,000 acre feet (35. 200 km³) at an elevation of 1,221. 4 feet (372. 3 m) .
• With 8 to 10 million visitors each year, including visitors to Hoover Dam but not all traffic across the dam, the Lake Mead National Recreation Area is the fifth busiest U.S. national park. Lake Mead National Recreation Area is located in southern Nevada and northwestern Arizona. The National Park Service ( NPS) is the United States federal agency that manages all National Parks, many National Monuments, and other conservation

The naming controversy

The dam, originally planned for a location in Boulder Canyon, was relocated to Black Canyon for better impoundment, but was still known as the Boulder Dam project. Work on the project started on July 7, 1930. Events 1456 - A retrial verdict acquits Joan of Arc of heresy 25 years after her death Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. At the official beginning of the project on September 17, 1930, President Hoover's Secretary of the Interior Ray L. Wilbur, announced that the new dam on the Colorado River would be named Hoover Dam to honor the then President of the United States. Events 1176 - The Battle of Myriokephalon is fought 1462 - The Battle of Świecino (or Battle of Żarnowiec Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. The United States Secretary of the Interior is the head of the United States Department of the Interior. Ray Lyman Wilbur ( April 13, 1875 &ndash June 26, 1949) was a Medical doctor, the 3rd President of Stanford University, and Wilbur followed a long-standing tradition of naming important dams after the President who was in office when they were constructed, such as Wilson Dam and Coolidge Dam. The Coolidge Dam is a reinforced concrete multiple dome and Buttress dam southeast of Globe Arizona on the Gila River. Furthermore, Hoover was already campaigning for re-election in the face of the Depression and sought credit for creating jobs. A Congressional Act of February 14, 1931, made the name "Hoover Dam" official. Events 842 - Charles the Bald and Louis the German swear the Oaths of Strasbourg in the French and German Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar.

In 1932, Hoover lost his bid for reelection to Franklin Delano Roosevelt. The United States presidential election of 1932 took place as the effects of the 1929 Stock Market Crash and the Great Depression were being felt intensely across the country In his memoirs, Hoover writes of stopping to inspect progress on the dam, by night, on November 12, 1932 on his way back to Washington from Palo Alto after his defeat. He commented, "It does give me extraordinary pleasure to see the great dream I have so long held taking form in actual reality of stone and cement. It is now ten years since I became chairman of the Colorado River Commission. . . . This dam is the greatest engineering work of its character ever attempted by the hand of man. " He went on to list its purposes, concluding, "I hope to be present at its final completion as a bystander. Even so I shall feel a special personal satisfaction. " (Hoover adds a footnote to this, see below. ) ^[20]

When Roosevelt took office on March 4, 1933, he brought Harold Ickes with him to replace Ray Lyman Wilbur as Secretary of the Interior. Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth Year 1933 ( MCMXXXIII) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar. Harold LeClair Ickes ( March 15, 1874 &ndash February 3, 1952) was a United States administrator and Politician Ickes wasted no time removing Hoover’s name from the Boulder Canyon Project. On May 8, 1933, Ickes issued a memorandum to the Bureau of Reclamation, which was in charge of the dam, stating, "I have your reference to the text for the pamphlet descriptive of the Boulder Canyon Project for use at the Century of Progress Exposition. Events 589 - Reccared summons the Third Council of Toledo 1450 - Jack Cade's Rebellion: Kentishmen Year 1933 ( MCMXXXIII) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar. I would be glad if you will refer to the dam as 'Boulder Dam' in this pamphlet as well as in correspondence and other references to the dam as you may have occasion to make in the future. "

This did not happen immediately, but over the following several years all references to "Hoover" Dam in official sources, as well as tourist and other promotional materials, vanished in favor of "Boulder" Dam.

Roosevelt died in 1945 and Harold Ickes retired in 1946. On March 4, 1947 California Republican Congressman Jack Anderson submitted House Resolution 140 to "restore" the name Hoover Dam. Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar. Userpolbot from http//bioguidecongressgov/scripts/biodisplaypl?index=A000196 Anderson’s resolution passed the House on March 6; a companion resolution passed the Senate on April 23, and on April 30, 1947, President Harry S. Truman signed Public Law 43 which read: "Resolved … that the name of Hoover Dam is hereby restored to the dam on the Colorado River in Black Canyon constructed under the authority of the Boulder Canyon Project Act … . Events 1079 - Omar Khayyám completes the Iranian calendar. 1454 - Thirteen Years' War: Delegates of Events 215 BC - A temple is built on the Capitoline Hill dedicated to Venus Erycina to commemorate the Roman defeat at Events 313 - Roman emperor Licinius unifies the entire Eastern Roman Empire under his rule Year 1947 ( MCMXLVII) was a Common year starting on Wednesday (link will display full 1947 calendar of the Gregorian calendar. Any law, regulation, document, or record of the United States in which such dam is designated or referred to under the name of Boulder Dam shall be held to refer to such dam under and by the name of Hoover Dam. "

Hoover writes this footnote to his comments of November 12, 1932: "Responding to a suggestion from Hiram Johnson, and with his characteristic attitude, Secretary Ickes changed the name of the dam. The hint in the above address that I should like to be present did not secure me an invitation to the dedication ceremonies conducted by President Roosevelt. I have never regarded the name as important. The important thing is a gigantic engineering accomplishment that will bring happiness to millions of people. In 1947, the Congress, by practically unanimous action, restored the name Hoover Dam — to Mr. Ickes intense indignation. " ^[21]

References

External links

• Hoover Dam's official website
• Official State of Nevada Tourism Site
• Hoover Dam: Lonely Lands Made Fruitful
• Historic Construction Company Project - Hoover Dam
• Hoover Dam in the Structurae database
• BBC - Hoover Dam, industrial and social history
• Hoover Dam page
• Dams of the Lower Colorado River - Hoover Dam
• Frank Crowe - Builder of Hoover Dam
• "Boulder Dam" – Part I and Parts III and IV, documentary films from the Prelinger Archives at the Internet Archive. Structurae is an online Database containing works of structural and Civil engineering of all kinds such as Bridges High-rise buildings The Prelinger Archives is a collection of Films relating to U The Internet Archive ( IA) is a Nonprofit organization dedicated to maintaining an on-line Library and archive of Web and
• Construction of diversion tunnel #4 and spillway tunnel which drops sharply to enter diversion tunnel
• Las Vegas and Water in the West The planning and construction of Hoover Dam is the central focus of this digital library. UNLV Special Collections houses the largest collection of primary materials relating to Hoover Dam.
• PBS American experience - Hoover Dam