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Hoover
Dam is a testimony to a country's ability to construct monolithic projects in
the midst of adverse conditions. Built during the Depression; thousands of men
and their families came to
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Millions of years of weather eroded the canyon walls. Water froze in cracks and crevices, splitting the rock. Before construction could begin on the dam, this loose rock had to be removed. Special men were required for the job, men called 'high-scalers.' Their
job was to climb down the canyon walls on ropes. Here they worked with
jackhammers and dynamite to strip away the loose rock. The men who chose to
do this work came from many backgrounds. Some were former sailors, some
circus acrobats, some were American Indians. All of them were agile men,
unafraid to swing out over empty space on slender ropes. |
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It was hard and dangerous work, perhaps the most physically demanding work on the entire project. Laden with tools and water bags, the men would descend the canyon walls. Jackhammer drills were lowered to them, and powder holes were drilled into the rock. The jackhammers weighed 44 lbs. and had to be maneuvered into position by hand Once the holes had been drilled into the rock, they were loaded with dynamite. After the shot, broken rocks sometimes had to be levered free using crowbars. Moving
about on the cliffs was difficult and dangerous. Live air hoses, electrical
lines, bundles of drill steel festooned the cliffs. The scalers had to
carefully pick their way through the resulting maze. The danger from falling
rocks and dropped tools was extreme. The most common cause of death during
the building of the dam was being hit by falling objects. The men began
making improvised hard hats for themselves by coating cloth hats with coal
tar. These 'hard-boiled hats' were extremely effective. Several men
were hit by falling rocks so hard that their jaws were broken by the impact,
yet they did not receive skull fractures. Because of these 'hard-boiled
hats,' men survived accidents which would otherwise have killed them.
The Six Companies contracted for commercially made hard hats and issued them
to every man on the project. The use of hard hats was encouraged, and deaths
from falling objects were reduced. |
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The risk and high visibility of the job lent it a certain status which appealed to some types of men. When the foremen weren't looking, they would swing out from the cliffs and perform stunts for the workers below. Contests were held to see who could swing out the farthest, the highest, or who could perform the best stunts. It
wasn't all done for fun and games, though. For several weeks, scaler Louis
'The Human Pendulum' Fagan transported a crew of shifters around a
projecting boulder on the Perhaps
the most famous feat any of the high scalers ever performed was a daring
midair rescue. Burl R. Rutledge, a Bureau of Reclamation engineer, fell from
the canyon rim. Twenty-five feet below, high scaler Oliver Cowan heard
Rutledge slip. Without a moment's hesitation, he swung himself out and seized
Rutledge's leg. A few seconds later, high scaler Arnold Parks swung over and
pinned Rutledge's body to the canyon wall. The scalers held Rutledge until a
line was dropped and secured around him and the shaken engineer was pulled,
unharmed, to safety. |
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Hoover
Dam is a part of the Bureau of Reclamations's multipurpose projects on the Lake
Mead, with a storage capacity of 28,537,000 acre-feet, is the largest
man-made lake in the The Hoover Dam Power Plant has 17 large generators and has a rated capacity of more then 2,000 megawatts. Through
the sale of power and water, the Bureau of Reclamation has been able to
return to the Federal Treasury the cost of its operations on the |
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The Dam Hoover Dam is a concrete arch-gravity type, in which the water load is carried by both gravity action and horizontal arch action. The first concrete for the dam was placed on June 6, 1933, and the last concrete was placed in the dam on May 29, 1935. The dam was built in blocks or vertical columns varying in size from about 60 feet square at the upstream face of the dam to about 25 feet square at the downstream face. Adjacent columns were locked together by a system of vertical keys on the radial joints and horizontal keys on the circumferential joints. Concrete placement in any one block was limited to 5 feet in 72 hours. After the concrete was cooled, a cement and water mixture called grout was forced into the spaces created between the columns by the contraction of the cooled concrete to form a monolithic (one piece) structure. Hoover Dam contains three and one-quarter million cubic yards of concrete. There are 4,360,000 cubic yards of concrete in the dam, powerplant, and appurtenant works. This much concrete would build a monument 100 feet square and 2-1/2 miles high; would rise higher than the Empire State Building (which is 1,250 feet) if placed on an ordinary city block; or would pave a standard highway, 16 feet wide, from San Francisco to New York City. |
Related Topics Hoover Dam Statistics |
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The Reservoir At
elevation 1221.4, Lake
Mead extends approximately 110 miles upstream toward the Recreation,
although a by-product, constitutes a major use of the lakes and controlled
flows created by |
Related Topics Colorado River Basin Map |
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The Power Plant There are 17 main turbines in Hoover Powerplant. The original turbines were all replaced through an uprating program between 1986 and 1993. With a rated capacity of 2,991,000 horsepower, and two station-service units rated at 3,500 horsepower each, for a plant total of 2,998,000 horsepower, the plant has a nameplate capacity of 2,074,000 kilowatts. This includes the two station-service units, which are rated at 2,400 kilowatts each. Hoover
Dam provides generation of low-cost hydroelectric power for use in Hoover
Dam's $165 million cost has been repaid, with interest, to the Federal
Treasury through the sale of its power. Hoover Dam energy is marketed by the
Western Area Power Administration to 15 entities in |
Related Topics Hydroelectric Generators |
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Dam Dimensions
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Reservoir Statistics
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Quantities of Materials Used in Project
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Concrete Mix Proportions
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The
Hoover Dam Powerplant is arranged in two wings, 650 feet in length, one on each
side of the river. There are nine main generator units on the
The primary parts of a generating unit are:
The Exciter
The Rotor
The Stator
The Shaft
The Turbines
The exciter sends an electric current to the rotor, a large electromagnet, charging it with a magnetic field. The rotor spins inside the stator, a tightly wound coil of wire. The moving magnetic field causes an electric current to move through the stator. This current, at 16,500 volts, leaves the generator and is then carried to the transformers where it is 'stepped up' to 230,000 volts for transmission. The rotor is propelled by a shaft connected to turbines. Water falling through penstocks connected to the reservoir supplies the energy to spin the turbines.
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