This is Bob Doughty.
this is Steve Ember with EXPLORATIONS in VOA Special English. Today we tell
about Hoover Dam. It was the largest and
most difficult structure of its kind ever built when work started in nineteen
report today about Hoover Dam must begin with the Colorado River. This river made the dam necessary. The Colorado River begins high in the Rocky
Mountains. It begins slowly, during the
dark months of winter. Heavy snow falls
on the Rocky Mountains.
snow is so deep in some areas that it will stay on the ground well into the hot
days of summer. But the snow does
melt. Ice cold water travels down the
mountains and forms several rivers -- the Gila River, the Green River, the
Little Colorado, the San Juan, the Virgin and the Gunnison rivers.
These rivers link together and form the
beginnings of the Colorado River. The
Colorado River flows through, or provides water for, the states of Wyoming,
Colorado, Utah, New Mexico, Arizona, Nevada and California. Then it crosses the
border into Mexico.
Colorado River has always been extremely powerful. The river created the huge Grand Canyon. The violent water cut hundreds of meters deep
into the desert floor of Arizona. The
Grand Canyon is proof of the power of this great river.
The Grand Canyon
was cut into the desert floor beginning thousands of years ago. But the power of this river has been
demonstrated in more modern times.
nineteen-oh-five and nineteen-oh-seven, the Colorado River caused great amounts
of flooding in parts of Arizona and California. Huge amounts of water ran into a low area in the dry, waterless desert
that had once been an ancient lake. In
two years of flooding, the Colorado River filled the ancient lake. That lake is called the Salton Sea. Today, it is about fifty-six kilometers long
by twenty-five kilometers wide. It is
even larger in years of heavy rain.
flooding that created the Salton Sea also flooded homes, towns and farming
areas. Many people were forced to flee
their homes. Government leaders knew
they had to do something to prevent such floods in the future.
In nineteen eighteen, a man named
Arthur Davis proposed building a dam to control the Colorado River. Mister
Davis was a government engineer. He said
the dam should be built in an area called Boulder Canyon on the border between
the states of Arizona and Nevada.
Building the dam would not be a simple
matter. The people of seven states and
the people of Mexico needed and used the water of the Colorado River. Much of that area is desert land. Water is extremely important. Without water from the Colorado River,
farming is not possible. Without water,
life in the desert is not possible.
November twenty-fourth, nineteen twenty-two, officials signed a document in
Santa Fe, New Mexico. That document is
called the Colorado River Compact. The
document tells how the seven states would share the water of the Colorado
River. It was agreed this could be more
easily done with the aid of a dam. Later
an agreement was signed with Mexico to supply it with water from the Colorado
area chosen for the dam was called Black Canyon. The walls of Black Canyon rise almost two
hundred forty-three meters above the river. An ancient volcano formed the rock in Black Canyon. Engineers decided the rock would provide a
good strong support for the proposed dam.
However, the area
also presented problems. The nearest
railroad was sixty kilometers away. There was no electric power. And,
in the summer, the temperature in the desert in Black Canyon could reach as
high as forty-eight degrees Celsius.
great deal of work was done before operations started on the dam. Workers built a town called Boulder City to
house employees working on the dam. They
built a large road from Boulder City to the area of the dam. They built a railroad from a main line in Las
Vegas, Nevada, to Boulder City. They
built another railroad from Boulder City to the dam area. And they built a three hundred fifty
kilometer power line from San Bernadino, California. This provided electric power to the area
where the dam was being built.
work on the dam began in April of nineteen thirty-one. Workers called "high scalers" were some of
the first to begin building the dam. They were suspended from ropes as they used heavy air-powered hammers to
break any loose rock away from the face of the canyon walls. When they could not use hammers, they used
dynamite. One high scaler became very
famous. His name was Arnold Parks. He
caught another worker who had fallen off the top of the canyon.
Parks held the worker to the wall of the canyon until others came to help.
Today, visitors can see a statue of the men who worked as high scalers to build
high scalers worked on the sides of the canyon. Other workers dug huge tunnels deep in the floor of the canyon. This was done to permit the Colorado River to
flow away from the construction area. This had to be done so the floor of the dam could be built.
June sixth, nineteen thirty-three, workers poured the first load of a building
material called concrete. Men in two
special factories worked day and night to make the concrete building material
for the dam.
equipment moved millions of tons of rock and sand. In the summer months, the terrible desert
heat slowed the work but did not stop it. Men who worked at night on the dam suffered less, but the heat was still
as high as thirty degrees Celsius.
the great dam began to rise from the floor of the canyon. From the canyon floor it reaches two hundred
twenty-one meters high. Workers poured
the last of the concrete on May twenty-ninth, nineteen thirty-five. They had used almost four million cubic
meters of concrete in the dam. Workers
also used more than twenty million kilograms of steel to strengthen the
concrete in the dam.
work was dangerous for the more than five thousand men who worked on the
structure. The extreme temperatures,
falling objects and heavy equipment caused accidents. The workers were provided with medical care
and two emergency vehicles to take them to a new hospital in Boulder City. However, ninety-six men lost their lives
during the building of the great dam.
companies building the dam had been given seven years to complete the
work. They did it in only five. The dam was finished on March first, nineteen
work now began. This work would make the
dam into one of the largest producers of electric power ever built. The dam was
built to control the powerful Colorado River. But it was also meant to use the river to produce large amounts of
seventeen huge machines use the river's power to produce electric power. The
states of Arizona and Nevada share the power. So do many cities in California,
including Los Angeles, Burbank and Pasadena.
the Hoover Dam was finished in nineteen thirty-six, it was the largest dam in
the world. It was also the tallest. And it was the largest power producer that
used water power to make electricity. Today this is no longer true. Taller dams, larger dams and a few that produce more power have been
created. But Hoover Dam is still a huge
and interesting place.
to Hoover Dam drive on a small road that passes Lake Mead. They enter a special visitors' center to
learn about the dam and the men who built it. They ride high-speed elevators that go deep inside the dam. They see the huge machines that produce
visitors say they thought the name of the huge structure was Boulder Dam. They are told that Hoover Dam is often
called Boulder Dam. However, it is named after former President Herbert Hoover.
he was president, Mister Hoover worked for many years to make the construction
of the dam possible. It was officially
named to honor him in nineteen forty-seven.
leave the great dam with an understanding of how difficult the project
was. They learn that it still safely
controls the great Colorado River. And
it also provides water and electric power to millions of people in the American
This program was written by Paul Thompson. It was produced by Mario Ritter. This is Steve Ember.
this is Bob Doughty. Join us again next
week for another EXPLORATIONS program in VOA Special English.