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Hoover Dam (S5, E15) | Modern Marvels | Full Episode — Transcript

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0:01The task, monumental and for many
0:03[music] deadly.
0:06Building the world's largest dam in one
0:08of the most unforgiving climates on
0:09Earth.
0:10Nothing like it had ever been attempted.
0:13Now, Hoover Dam on Modern Marvels.
0:29Located in the middle of America's
0:31Southwestern desert, stands a true
0:33[music] giant in the history of human
0:35ingenuity and accomplishment.
0:38Built in the 1930s,
0:40Hoover Dam holds back trillions of
0:42gallons of life-sustaining water,
0:44provides prodigious amounts of
0:46hydroelectric power,
0:48and inspires all as a structure of
0:50monumental proportions.
0:53At 726 [music]
0:54ft, Hoover Dam is as tall as a
0:56skyscraper.
1:00At the base of the dam,
1:02the concrete is an incredible 660 ft
1:05thick.
1:08The amount of concrete [music] used to
1:09construct Hoover Dam could build a
1:11two-lane highway from Los Angeles to
1:13Boston.
1:16Well, from the outside the dam appears
1:18to be a solid wall of concrete. Inside,
1:21it's laced with 2 mi of corridors and
1:23tunnels.
1:27The dam holds back nearly 2 years of the
1:30Colorado River's average flow
1:33and creates a 110-mi long Lake Mead.
1:36It's America's largest man-made
1:38reservoir
1:39and is located in one of the driest
1:41places [music] on Earth,
1:4330 mi southeast of Las Vegas, Nevada.
1:46>> [music]
1:52[music]
1:53>> The primary reasons the dam was built
1:56were flood control and to guarantee a
1:57steady [music] water supply to the
1:59quickly growing population in the
2:00Southwestern United States.
2:05Generating electricity was secondary,
2:07[music]
2:07but now much of the modern Southwest
2:09depends on the dam to feed its
2:10power-hungry lifestyle. [music]
2:16To generate electricity,
2:18water is fed into 30-ft diameter pipes
2:21called penstocks [music]
2:23via the four intake towers standing in
2:25Lake Mead.
2:27Once it goes into the 30-ft diameter
2:28water pipe, [music] the water's
2:29traveling at about 12 mph, which is fast
2:32for water, but not fast enough to turn
2:33our generators. Uh, the rotating weight
2:35of [music] the generators itself is 800
2:37tons. So, we need to increase the speed,
2:39and we do that by continuously reducing
2:41the size [music] of the pipe. 30 ft
2:43becomes 13, 13 narrows down to a scroll
2:45case, which is 4 ft in diameter. By the
2:48time the water actually reaches the
2:49turbine, it's going approximately 85
2:51mph.
2:53Eventually, it hits the turbine runner,
2:55which we've I've got one out for
2:56maintenance here in the background. This
2:58turbine runner weighs 35 tons. It's
3:00stainless steel. The water impacting
3:02that turbine runner causes it to rotate
3:05180 rpms, 180 times per minute.
3:09That rotation is transferred through a
3:10solid shaft up to our generator rotor.
3:14When you push a generator, what you're
3:15doing
3:17is you're moving magnetic fields across
3:19wires. We have our big electromagnets on
3:22the rotor of the machine, and then we
3:24have stationary wires that we call the
3:26stator. And when those magnetic fields
3:29cross across the stator, it pushes
3:32electrons through those big wires in the
3:34stator, and that's the electrons on
3:36their way to our transformer and out to
3:38the world.
3:40The electricity leaves the transformers
3:42on power lines strung up along the sides
3:45of the canyon.
3:46Behind me, you'll see what they call
3:47cantilever towers. They appear to be
3:49falling into the canyon, but they're
3:51not. They're actually leaning into the
3:52canyon, and they're designed to be that
3:54way. What we want to do is take the
3:55power lines up and over the canyon walls
3:57without having them touch the same
3:59canyon walls, otherwise they would short
4:01out. And that's mainly due to the
4:02ferrous material that's inside those
4:04canyon walls.
4:06In other words, there's enough iron
4:08content in the canyon walls to cause the
4:10electricity to arc off the cables if
4:12they were allowed to get too close.
4:17There are 17 generators in Hoover Dam's
4:19huge power plant,
4:21and they produce more than 4 billion
4:23kilowatt hours a year.
4:26We have a service area including all of
4:28Southern California
4:30and Arizona, probably more than 20
4:33million people that receive some of the
4:35power.
4:36Despite Hoover Dam's massive [music]
4:38size,
4:39like so many of the construction
4:41projects of the 1930s, there's an
4:43elegance built into it.
4:49Notable artists brought a touch of class
4:50to this once [music] bleak and desolate
4:52canyon.
4:56Inside,
4:58art deco designs [music]
4:59and portions are found in the ornate
5:01visitor elevators,
5:03gleaming aluminum doors,
5:05and decorative railings [music] in the
5:06powerhouse.
5:08Inlaid in the terrazzo floors
5:11are designs [music] inspired by Native
5:12American art that symbolize the power of
5:15the dam.
5:18At the halfway point along one of the
5:19main [music] corridors that runs through
5:21the dam,
5:22a design marks the border between
5:24Arizona and Nevada.
5:29Hoover Dam epitomizes [music] humanity's
5:31discontent with accepting nature's
5:33rules.
5:35It transformed [music] the environment
5:37around it.
5:40Building the dam was a colossal [music]
5:41undertaking in 1931.
5:44It was the largest government project
5:45ever attempted.
5:48Constructed in the depths of the
5:49depression,
5:51it promised to change barren to
5:52bountiful.
5:54The Southwest is an arid area, and
5:57without a dam like Hoover Dam to control
6:00the flow of the river and make the water
6:02available when it's needed, uh, we just
6:05couldn't have the level of economic
6:06development [music] that we have in the
6:07Southwest today.
6:09Hoover Dam was the first major attempt
6:11[music] to tame the mighty Colorado
6:13River,
6:14the same river that carved the Grand
6:16Canyon.
6:20Snow melting in the Rocky Mountains
6:21sends a torrent of water down the
6:23Colorado every spring,
6:26but then dries to a trickle by summer.
6:29The 1,400-mi long river drains water
6:32from seven states, Wyoming, Nevada,
6:37Utah, Colorado,
6:39New Mexico,
6:40Arizona,
6:42and California,
6:43and empties into the Gulf of California.
6:47The early settlers who were trying to
6:49build an economy, build lives at the
6:52bottom end of this river, they planted
6:54their crops and built their fields and
6:56built homes and businesses, [music]
6:58in the spring times those would be
6:59subject to inundation or destruction
7:02because of the floods coming down the
7:04river. And by the end of the summer
7:07[music] when the farmers really needed
7:08that water to get their crops to
7:09maturity, they couldn't get to the
7:11water.
7:13Attempts to harness the power of the
7:15Colorado River date back more than a
7:16century.
7:19In 1901,
7:22a private company constructed a canal
7:24system that brought water from the
7:25Colorado River
7:27and delivered it to the arid but fertile
7:29Imperial Valley of Southern California.
7:32The company cut an opening in the
7:33western bank of the Colorado River and
7:35installed a headgate,
7:37which controlled water flow.
7:40Initially, the system [music] of small
7:41gates and channels worked beyond
7:43expectation.
7:45Fields produced a bounty [music] of
7:47agricultural products.
7:50Soon, thousands of people flocked to the
7:52Imperial Valley with dreams of finding a
7:54new Eden,
7:57but their dreams soon turned into a
7:59nightmare.
8:02The problem was these were not very
8:03well-engineered works, and they weren't
8:05very good. Then the Colorado River in
8:071905 had a major flood come down the
8:09river, and it washed out these headworks
8:12and flowed into the Imperial Valley for
8:1418 [music] months. Essentially, created
8:17what is today the Salton Sea, destroyed
8:19much of the agricultural land, destroyed
8:22homes, destroyed businesses, [music]
8:24really wreaked havoc.
8:26If the breach wasn't repaired,
8:29experts predicted the Salton Sea would
8:31continue [music] to grow
8:33and eventually drown millions of acres
8:35of California and Arizona.
8:38It wasn't until early 1907 that the
8:41breach was successfully closed, but it
8:43was considered only a temporary
8:44solution.
8:46In 1922,
8:48Arthur Powell Davis, director of the US
8:50Bureau of Reclamation,
8:52recommended a series of reservoirs to
8:54control the entire river.
8:58Known as the Fall-Davis report,
9:01the centerpiece of the plan was a
9:02colossal dam to be built in Boulder
9:04Canyon between Nevada and Arizona.
9:10Before the measure could proceed,
9:12the states had to decide on an equitable
9:14division of water.
9:17Arizona believed California was trying
9:19to steal an unfair share of water
9:22and blocked legislation for [music]
9:23several years.
9:25There's always a a fight over water in
9:27the West. When water is scarce, there's
9:30going to be tension over water, and and
9:32that was the case
9:34uh years ago. It's still the case today.
9:37Finally, in 1929, the Boulder Canyon
9:41Project Act passed in Congress.
9:44>> [music]
9:45>> The Bureau of Reclamation worked to
9:47design a structure capable of holding
9:50back trillions of gallons of water in a
9:52very high, yet narrow canyon.
9:57They considered many different designs
9:59before finding the answer.
10:03Hoover Dam is a combination [music] of
10:05gravity
10:06and arch. Gravity dams are dams that are
10:10just so massive
10:12that they can their weight of them
10:14themselves can hold back
10:16the the weight of the water behind them.
10:19And then arch dams traditionally are
10:21built in the shape of an arch and
10:23they're actually keyed into canyon
10:25walls. The weight of the water presses
10:27the arch into the sides of the canyon
10:29walls and there's strength in the arch.
10:32It's kind of like an eggshell. If you
10:34try to press in on the edge of an egg,
10:36an eggshell is very thin, but the egg
10:38itself is very strong. If you try to
10:40press in on the edge of a
10:42on the on the two ends of an egg, you'll
10:43find that you can't you can't crush an
10:45egg. It's the strength of the arch.
10:48The Bureau of Reclamation's planned arch
10:50gravity dam
10:52would not only be the largest dam in the
10:53world.
10:55It was to be built in one of the most
10:56desolate areas on Earth.
10:59I sometimes question the audacity of the
11:01people who had the courage and the
11:03conviction to think they could build a
11:05dam out in the middle of a desert
11:06[music] where nothing existed. There
11:08were no roads to the site. There was no
11:10power to the site.
11:12There was no labor force here.
11:14There was nowhere for the people to live
11:16who were going to come and build the
11:17dam.
11:18In spite of all the obstacles, the dam
11:21had to be perfect. Surveyors decided to
11:24move the location from Boulder Canyon to
11:26Black Canyon, 8 miles downstream. Black
11:29Canyon, the site where we actually are
11:31today, was chosen mostly because of the
11:33fissures that are underneath where we
11:35are today. There were less fissures here
11:37in this area. Now, the rock is some of
11:39the best rock that you can find for
11:41placing a dam. It's called andesite
11:42breccia. It actually has a tighter
11:44granular composition than granite.
11:48The location was set.
11:50But the task ahead was great.
11:52Hire an army of thousands.
11:55Divert the river around the dam site.
11:57And form a mountain of concrete into a
12:00dam.
12:01All in the middle of nowhere.
12:04One question remained.
12:08Could it be done?
12:12Lake Mead, the reservoir created by
12:14Hoover Dam, contains enough water to
12:17cover the entire state of Pennsylvania
12:19with 1 foot of water.
12:22Hoover Dam will return on Modern
12:24Marvels.
12:40Hoover Dam [music] may be an icon of
12:42American ingenuity.
12:44But the structure itself
12:46is only the end product of an elaborate
12:48engineering, logistical,
12:50and human story.
12:54In 1930, the Bureau of Reclamation,
12:57the government agency responsible for
12:59water management in the western United
13:01States,
13:02had to first build a railway supply line
13:04from Las Vegas to Black Canyon.
13:07>> [music]
13:07>> The site chosen for the new dam.
13:12Although the site had changed from
13:13Boulder Canyon to Black Canyon,
13:15the endeavor was still [music] called
13:17the Boulder Canyon project.
13:19People naturally anticipated the name
13:21[music] would be Boulder Dam.
13:23But at a railroad spike driving
13:25ceremony,
13:26Ray Wilbur, Secretary of the Interior
13:28under President Herbert Hoover,
13:30set the record straight.
13:33Secretary of the Interior, [music]
13:35Ray Lyman Wilbur, came out to drive the
13:37silver spike to begin construction of
13:39the railroad spur from Las Vegas out to
13:41Boulder City town site.
13:44And that day is the day that he
13:45announced, "Well, we're going to call it
13:47Hoover Dam."
13:48Well, this was a year after the stock
13:50market had crashed and the depression
13:52was settling in and people were not at
13:54all happy with Hoover.
13:56Despite the public's disapproval of
13:58President Hoover,
13:59they welcomed the new job opportunities.
14:02People were desperate for work.
14:05Soon thousands poured into the Las Vegas
14:07area in hopes of finding employment.
14:10Before [music] the construction started,
14:12before they hired anybody, they came
14:14because they knew there was a chance of
14:17a job. Just a rumor of a job.
14:22Before any of today's social programs,
14:25the only choice the unemployed had was
14:26to search out [music] work
14:28wherever it might be.
14:31Unfortunately, the dam was to be built
14:33in one of the most inhospitable climates
14:35in the world,
14:37where temperatures regularly reached
14:38120°.
14:41And shelter simply didn't exist.
14:45Desperate people brought their entire
14:46families. They set up makeshift camps or
14:49lived in their cars while waiting for
14:51work.
14:54Unsanitary living conditions and heat
14:57claimed several lives that first summer.
15:00The government planned to build Boulder
15:01City, an elaborate construction camp for
15:04its workers.
15:06But it wouldn't be built for more than a
15:08year.
15:10Problem was
15:12that the depression caught the
15:14government off guard. They had hoped
15:16that they would be able to have the city
15:18built and finished before people could
15:21move in and then they would start work
15:23on the dam. But the stock market crashed
15:26and people started moving in. On January
15:3010th, 1931,
15:32the true scope of the project became
15:34public knowledge.
15:36The Bureau of Reclamation supplied plans
15:38to any company interested in placing a
15:40bid on the construction of the dam.
15:43And it seemed everyone was interested in
15:45what was sure to be the largest
15:47government [music] contract ever
15:48awarded.
15:51Blueprints detailed an immense
15:53structure.
15:55The process of dam building called for
15:57three enormous undertakings.
15:59First, tremendous tunnels, over 50 feet
16:02in diameter, were needed [music] to
16:03divert the course of the river.
16:05Then temporary cofferdams would be
16:07erected to provide a dry work area.
16:10And finally, 3 and 1/4 million cubic
16:13yards of concrete would be poured to
16:16build the dam itself. The sheer size of
16:18the project intimidated even the most
16:20confident contractors.
16:22The challenge was monumental.
16:24Build the world's largest dam in the
16:26middle of the desert in less than 7
16:28years, the government imposed deadline.
16:31Back in the '30s, there was no one
16:33company that could accomplish the
16:35building of the Hoover Dam. It was such
16:37a massive project. So, six individual
16:40companies actually got together and
16:42formed one entity and they called
16:43themselves Six Companies.
16:47All of the firms that made [music] up
16:48Six Companies were familiar with big
16:50projects.
16:51They had independently shaped the west,
16:54building railroads, [music]
16:55tunnels, bridges,
16:57and highways.
17:00Between the six,
17:02perhaps they had enough experience and
17:03resources [music]
17:04to build a dam of such great magnitude.
17:07But they needed someone who was
17:09respected in the field of dam
17:10construction to oversee the project.
17:13And they chose Frank [music] Crowe to be
17:15their
17:16foreman here, superintendent of the job.
17:19>> [music]
17:19>> And he was a hands-on foreman.
17:22He he didn't spend much time behind his
17:24desk. [music]
17:26Frank Crowe was the most respected dam
17:28builder in America.
17:30Born in 1882,
17:32he was a seasoned veteran with more than
17:3420 years of experience
17:36and had developed [music] important
17:37time-saving and innovative construction
17:39methods.
17:42With Crowe on board, Six Companies
17:45was ready to make a bid for the dam
17:46construction.
17:48On March 4th, 1931,
17:50the Bureau of Reclamation [music]
17:51opened sealed bids.
17:53Six Companies firm won the contract with
17:56the lowest bid of $48,890,955.
18:00[music]
18:04LET'S GO.
18:05OKAY.
18:08BLASTING BEGAN ALMOST IMMEDIATELY.
18:11SIX Companies had their work cut out for
18:13them.
18:14Initially, even getting to the dam site
18:16was an obstacle.
18:18As there were no roads from the rim to
18:19the bottom of the canyon,
18:21men had to ride ferries to the dam site.
18:25Later, cableways were erected across the
18:27canyon
18:28to get men and materials to the bottom.
18:32The first monumental task
18:34was the diversion of the river around
18:36the dam site.
18:37Engineers needed a dry work area in
18:39which to set the dam.
18:42Four enormous tunnels had to be drilled
18:44through the canyon walls to circumvent
18:46the site.
18:48The tunnels would have to carry the
18:49entire volume of the Colorado River.
18:54Granted the pressure,
18:56the Bureau of Reclamation initiated
18:57stiff fines for missed deadlines at each
19:00stage of construction.
19:05Workmen drilled blasting holes and
19:07loaded them with dynamite.
19:09A special three-story truck holding
19:11drillers at three different levels
19:13expedited the process.
19:19An endless stream of trucks removed
19:21blasted rock from the diversion tunnels
19:24and labored up the steep incline for
19:25disposal.
19:27Three shifts of men worked 24 hours a
19:29day, 7 days a week to keep the tunnels
19:32on schedule.
19:34Frank Crowe was responsible for keeping
19:36things moving.
19:37And so, it was hurry up, hurry up, hurry
19:39up. And in fact, his nickname was Hurry
19:42Up Crowe. We've got to get all this
19:45done. He was uh
19:47really was a genius in his way.
19:50The hectic pace of construction had its
19:52consequences.
19:54Heat exhaustion cost 14 men their lives.
19:57After the depression and the crash, it
20:00was so difficult to get a job. Companies
20:02like the Six Companies could easily
20:04afford to cut a lot of corners in terms
20:07of safety and health of their workers,
20:09in terms of pay, in terms of comfort,
20:11and that kind of thing, and they did.
20:13Tensions came to a head in the scorching
20:15summer of 1931.
20:18Striking workers demanded better working
20:20conditions, [music]
20:20fresh water, and improved safety
20:23precautions.
20:25Six Companies responded by firing 1,400
20:28strikers and hiring fresh workers
20:30readily available because of the
20:31depression.
20:35I came here in August 1931, and I worked
20:39as a truck driver down at the dam site.
20:42I remember one stretch of 10 months
20:44without a day off, and we were working 7
20:47days a week.
20:49And uh the pay was to me was great. It
20:52was $5 a day.
20:54More than 5,000 men worked on the dam at
20:57the height of construction.
20:59Frank Crowe's hardworking team completed
21:01the diversion tunnels months ahead of
21:03schedule.
21:05After digging the diversion tunnels,
21:07workers lined them with 3 ft of
21:09concrete. Special forms of gigantic
21:12proportion moved along the interior of
21:14the tunnels.
21:16But the job had just begun, and the most
21:18spectacular work was yet to come.
21:25Roughly 100 workers lost their lives
21:27creating Hoover Dam. Coincidentally, the
21:30first and last persons killed on site,
21:33J. G. Tierney and P. W. Tierney, were
21:36father and son.
21:39Hoover Dam will return on Modern
21:41Marvels.
21:46Overwhelming in its scope and size,
21:48Hoover Dam draws visitors from around
21:50the world. [music]
21:52The first tours were given in 1937.
21:55As of 2005, [music]
21:57it's estimated that more than 39 million
22:00people have come all [music] the way to
22:01Black Canyon to experience the dam.
22:05They get a sense of awe, the amount of
22:08effort that it took to build such a
22:10massive structure. [music] Back in the
22:12'30s, they didn't have computers, you
22:14know, they had a slide ruler, a pencil,
22:16and [music] eraser. There was just a
22:18huge amount of blood, sweat, and tears,
22:21literally, put into the building of
22:22Hoover Dam.
22:25Hanging on the parking structure
22:27is a sculpture of a high scaler, one of
22:29the dam builders who prepared the canyon
22:31walls for construction.
22:33It pays tribute to the thousands of
22:35workers who came to this rugged and
22:37desolate place to work on the dam.
22:40A plaque on the pillar lists those who
22:42lost their lives during the difficult
22:45and often dangerous construction.
22:47>> [panting]
22:48>> No job was more precarious than that of
22:51high scalers.
22:54The jagged canyon walls required
22:56smoothing and shaping for the abutting
22:58dam,
22:59and thousands of cubic yards of rock
23:01needed to be blasted from the sheer
23:03canyon faces.
23:05Enduring acrobatic displays,
23:07high scalers swung from ropes to
23:09accomplish the bold feat.
23:12The high scalers had to hang off the
23:14side of the canyon wall sitting in
23:15bosun's chairs suspended by ropes. They
23:18carried a 44-lb pneumatic drill. They
23:20drilled holes into the canyon wall,
23:22placed dynamite charges into those
23:24holes. They then swung away as a
23:26dynamite exploded, swung back to the
23:28original positions, prying off the
23:30broken pieces of rock with steel levers.
23:33When dam construction began, government
23:36policy dictated that the high scalers
23:38and all employees should be out of the
23:40squatter-style camps and into more
23:42acceptable [music] living conditions.
23:46Six Companies labored to provide housing
23:49for its workers as quickly as possible
23:51and built Boulder City, 7 miles from the
23:54work site.
23:56They built everything that a city should
23:59have. In the planning for Boulder City,
24:01it was decided that it would be a full
24:03community. It would have a movie
24:05theater.
24:06>> [music]
24:06>> It would have entertainment. It would
24:08have schools for the children. It would
24:10have churches for people to go to.
24:13Boulder City was normal in all senses,
24:16except that it was a government
24:17reservation.
24:19The Secretary of the Interior, Ray Lyman
24:21Wilbur, appointed Sims Ely to manage the
24:23city of 7,000 residents.
24:27A man who commanded respect,
24:29Sims Ely acted as judge, mayor, and
24:32Chamber of Commerce.
24:34He decided who would be given business
24:36licenses and what types of businesses
24:39they could have.
24:40Unlike many others during the
24:42depression, people in Boulder City had
24:44some money to spend.
24:46But by choosing which businesses were
24:47allowed in town, Sims Ely determined for
24:50his workers how to spend their money
24:52more responsibly.
24:55Six Companies paid their men partially
24:57in script. This was money that was
24:58printed by Six Companies, and they could
25:00only spend it at the company store in
25:03Boulder City.
25:05Boulder City was a company-controlled
25:07town. As city manager, Sims Ely was also
25:10responsible for enforcing the law
25:13and had federal marshals on site to help
25:15him do it.
25:16Alcohol and gambling were not allowed
25:18within the city limits.
25:20But in nearby Las Vegas,
25:23just about everything was.
25:28Las Vegas offered an escape from the
25:30rigid rules of Boulder City.
25:33Boulder fueled the commerce and growth
25:35of Las Vegas.
25:37And like the international attraction it
25:38is today,
25:40Las Vegas accepted all varieties of
25:42currency.
25:43The workers would go down to Las Vegas
25:45onto Block 16, which is the red light
25:47district, and they would drink, and they
25:49would gamble, and they would get
25:51serviced in the houses of prostitution
25:53along Block 16, and they would pay for
25:55it with the script. Then the prostitutes
25:58take the script they earned and come
25:59back up to Boulder City with it and go
26:01shopping.
26:04Boulder City's location, only 30 miles
26:06from rowdy Las Vegas, emphasized the
26:09fact that it was a haven.
26:11There was very little crime in Boulder
26:13City, and to many it was a paradise, a
26:15sanctuary,
26:17safer from the evils of the outside
26:18world.
26:20It was a model town. It was perfect.
26:22[music]
26:23It was meant to be perfect. You couldn't
26:25have have any kind of alcohol. You
26:28better not.
26:31Boulder City offered security, shelter,
26:33and a full belly.
26:35The food was good, and there was plenty
26:37of it.
26:39When others were starving, workers in
26:41Boulder [music] City feasted on three
26:42square meals a day.
26:45The Anderson Brothers mess hall served
26:47as [music] many as 1,300 men per seating
26:51and prepared as many as 6,000 meals a
26:53day.
26:55Boulder City was more than a
26:56construction camp.
26:58It was a place where people could get a
27:00new start.
27:01But Boulder City wasn't for everyone.
27:05It was supposed to be a perfect town,
27:07but the segregation was tremendous, too.
27:10They They had one black crew that worked
27:12on the dam.
27:14There was about 14 or 15 members. They
27:16could not even live in Boulder City.
27:20>> [music]
27:21>> Fewer than 1% of dam employees were
27:23African-American, and they were assigned
27:25the least [music] desirable positions.
27:28The new Secretary of the Interior,
27:31Harold Ickes, hoped to alter the
27:33situation,
27:34but he didn't have authority to change
27:36Six Companies' hiring practices.
27:39He did, however, have authority in
27:40Boulder City.
27:43He announced in 1933
27:45that the few African-American employees
27:48could live there.
27:49It was a minor victory for those who
27:51found discrimination a way of life.
27:58For all the men,
27:59Hoover Dam offered work during the
28:01crushing Great [music] Depression.
28:04Once the dam began to rise from the
28:06bottom of Black Canyon,
28:08those men would see they were part of
28:10something growing to historic
28:11proportions,
28:14something that would demand the
28:15development of new technologies before
28:17it could be completed.
28:21Herbert Hoover, [music] champion and
28:23namesake of the dam, only visited it
28:25once during construction in 1932.
28:27[music]
28:31Hoover Dam will return on Modern
28:33Marvels.
28:42More than once over the years, Hoover
28:44Dam has suffered something of an
28:46identity crisis.
28:49It was originally referred [music] to as
28:51Boulder Dam,
28:52even though it ended up being built in
28:53Black instead of Boulder Canyon.
28:56Construction began during Herbert
28:58Hoover's administration,
29:00and it became Hoover Dam.
29:03Herbert Hoover was very instrumental in
29:05getting this Black Canyon Project Act
29:08put through Congress so the dam could
29:09get built. [music]
29:10But what happened was when the Roosevelt
29:12administration came into play, they
29:14didn't really care for Herbert Hoover,
29:17and they didn't like calling it Hoover
29:19Dam, so they [music] made a statement
29:21calling it Boulder Dam. Even to this
29:24day, I'll have people come up to me and
29:26ask, "Where's Boulder Dam?"
29:28It wouldn't be until 1947 that an act of
29:31Congress made Hoover Dam the official
29:33name.
29:35But fortunately, the great name debate
29:37didn't impede progress on the dam.
29:40On November 14th, 1932,
29:43water began flowing through the great
29:44diversion tunnels.
29:47Men successfully forced the entire
29:49Colorado River from its ancient bed.
29:53Then the two [music] temporary dams,
29:55called cofferdams,
29:57were erected to provide the dry work
29:58area.
30:00The cofferdams are both earthen. The one
30:02that is [music] upriver is actually a
30:03larger one. It was the one of the larger
30:05dams in the world when it was
30:06constructed. Almost 100 ft high, but 700
30:10ft [music] thick. It's actually thicker
30:12than the Hoover Dam is. Lower cofferdam
30:14needed to be of course much smaller cuz
30:16all it was doing was allowing water not
30:17to back up on the workers. Water was
30:19then pumped from between the dams, and
30:21excavation began.
30:24Excavation was a monumental undertaking.
30:29More than 40 ft of rock, sand, and silt
30:31had to be removed from the now dry
30:33riverbed.
30:36Steam shovels dredged a half million
30:38cubic yards of material [music] in
30:40preparation for pouring concrete.
30:43And on June 6th, 1933,
30:45the first bucket of concrete poured into
30:47the form at the bottom of the canyon.
30:53Producing enough concrete for the dam
30:54was a problem in itself.
30:57Hoover Dam required nearly as much
30:58concrete
31:00as all previous Bureau of Reclamation
31:02dams combined.
31:06A nearby riverbed provided the gravel.
31:09Men loaded material into train cars and
31:12transported it to the separating plant,
31:14where it was divided by size.
31:17Trains then hauled gravel to the two
31:19mixing facilities built to produce the
31:21tremendous amount of concrete.
31:25Night and day, concrete left the mixing
31:27plant, truckload after truckload,
31:30bucket after bucket, for placement in
31:33the dam forms.
31:37It's not one monolithic piece.
31:39It's poured more like a kid's LEGO toys
31:41that lock together like that. Then they
31:43poured grout in between the walls. Uh
31:45so, they poured it in individual blocks.
31:51The dam was built up in forms from 25 to
31:5460 ft square and 5 ft deep.
31:59If they had poured it as one massive
32:00block,
32:01not only would it be inclined to crack,
32:04but it would take over 125 years to
32:07completely harden.
32:09The chemical reaction of hardening
32:11concrete also produces heat.
32:14Too much heat would cause the huge
32:15concrete blocks to crack.
32:17So, steel pipes were [music] inserted
32:19into the wet concrete, and cold water
32:21pumped through them to reduce cracking.
32:25A project of this magnitude and such
32:28strict deadlines required many
32:30innovative construction techniques.
32:33Frank Crowe pioneered the extensive use
32:35of cableways on earlier projects,
32:37but never before [music] had cableways
32:39been used so efficiently.
32:43>> [music]
32:43>> From 1/8 of a mile above,
32:45cableway operators choreographed a
32:47ballet of man and machine.
32:50Train [music] cars transported concrete
32:52buckets from the mixing plant.
32:55Cableway operators lifted the 22-ton
32:57buckets and sent them gliding to the
32:59appropriate form.
33:07There men released the [music] safety
33:09locks, and 16 tons of concrete poured
33:11into the form.
33:14Activity progressed [music] 24 hours a
33:16day, 7 days a week, as workers poured up
33:19to 1,100 buckets of concrete per day.
33:22This kind of dangerous work led [music]
33:25to another innovation at the dam site.
33:28We believe that this is where the hard
33:30hat was invented that everybody uses
33:32nowadays. The construction workers have
33:35been faced with debris falling on them
33:37from above,
33:39and they realized that they were going
33:41to have to do something. And so, what
33:43they did was
33:45they put two baseball caps together like
33:47this with the bill going this way and
33:50with this way.
33:51And then they dipped it in tar and let
33:54it harden and dipped it in tar and let
33:56it harden.
33:57>> [music]
33:57>> And these were all homemade hats.
33:59Company didn't have anything to do with
34:01this.
34:02But when several men wearing these
34:04so-called hard-boiled hats were saved
34:07from falling debris,
34:08six companies purchased thousands of
34:10them for their employees.
34:13As the dam grew taller, so did the tales
34:16surrounding the project.
34:18Despite rumors, no one is buried in the
34:19concrete.
34:21A decomposing body would have threatened
34:24the integrity of the dam. Besides, an
34:26average pour only increased the
34:27concrete's depth by a few inches.
34:31While the concrete was being poured,
34:34there were several ancillary projects
34:35happening simultaneously.
34:39The four steel-reinforced concrete water
34:42intake towers were built behind the dam.
34:45Mounted nearly halfway up the sides
34:47[music] of the canyon,
34:48towers only had to be 395 ft tall.
34:53Manufacturing the giant steel penstocks
34:56needed to feed water from the intake
34:57towers to the turbines
35:00tested the resources [music] of the day.
35:04The 30-ft diameter pipes were too large
35:06to ship, so an entire fabrication
35:08facility was erected close to the dam.
35:12Giant presses [music] rolled 2 and
35:143/4-in steel plates
35:16into 11-ft pipe sections weighing 80
35:19tons each.
35:22Two pieces combined to make one colossal
35:24[music] section 22 ft long.
35:27Tractors moved the enormous sections to
35:29the canyon rim,
35:32where the largest cableway floated them
35:33into the base of the dam.
35:36Each section [music] was joined to other
35:38sections forming over 1 mile of welded
35:40pipe.
35:43On each side of the dam, engineers
35:45designed a spillway [music] to protect
35:47it in times of great flooding.
35:49If the water ever got high enough where
35:51it would endanger the dam by going over
35:52the top of the dam, which would destroy
35:54the power plant below, water actually
35:56goes over the sides, and it goes down
35:58through large uh 50-ft diameter tubes
36:01that push the water around the side of
36:02the project. Now, those have been used
36:04twice in history, once in 1941 and again
36:07in 1983.
36:09That year, water flowed over the [music]
36:11spillways at 52,000 cubic feet per
36:13second.
36:16Despite the record water flow,
36:18the spillways performed just as their
36:20designers had intended
36:22and helped minimize flooding downriver.
36:26When the spillways were constructed, the
36:29dam was one step closer to completion.
36:32But there was a lot at risk, and only
36:34one way to test the structure. Fill Lake
36:37Mead and see if the dam would be able to
36:39hold back the pressure exerted by
36:41trillions of gallons of water.
36:45From 1939 to 1949,
36:48Hoover Dam's power plant was the world's
36:50largest [music] hydroelectric
36:51installation.
36:52It is still one of America's biggest
36:55facilities.
36:57Hoover Dam will return on Modern
36:59Marvels.
37:07When Hoover Dam was finished in [music]
37:081935,
37:10it was the biggest dam in the world,
37:12which under Frank Crowe's leadership was
37:14completed faster and for less money than
37:16initially planned.
37:18To accomplish what Frank Crowe did
37:212 years ahead of schedule and under
37:22budget,
37:24had to be a tremendous individual. Maybe
37:26not loved by everybody, but certainly he
37:29set out to build the dam, and he
37:31accomplished that.
37:33Over 21,000 workers had labored on the
37:35massive project. For them, the end
37:37product became more than just a
37:39combination of sweat and concrete.
37:42At the time we completed it,
37:44I just felt that I had been a part of
37:46something that was just [music]
37:47tremendous.
37:49On September 30th, 1935,
37:52President Franklin Delano Roosevelt came
37:54to dedicate the dam that so many had
37:56worked so hard [music] to complete.
37:59Four months before Roosevelt's
38:00dedication, Lake Mead began filling.
38:05It took 6 years to reach maximum
38:07capacity,
38:08and the mighty structure successfully
38:10held back trillions of gallons of water.
38:15There was no shortage [music] of pride
38:17in what was accomplished in Black
38:18Canyon.
38:20And in 1938,
38:22sculptor Oscar JW Hansen completed a
38:25memorial next to the dam featuring two
38:27statues called The Winged [music]
38:29Figures of the Republic.
38:32He wanted to make a statement about the
38:33workers on the project, and that
38:35statement was built by man, the Hoover
38:37Dam, but not the average man. They're 30
38:40ft tall, they weigh 4 and 1/2 tons of
38:43statuary bronze, and you notice they've
38:45aged to a lovely green color except for
38:46the toes. It is considered good luck in
38:49Hoover Dam folklore to rub the toes.
38:52Inlaid on the floor around [music] the
38:54statues are 209 discs of various sizes.
38:58They indicate the positions of the
38:59brightest stars and planets that were
39:02visible [music] from this exact location
39:04at 8:56 p.m. on the 30th of September,
39:071935,
39:09the day of President Roosevelt's
39:10dedication.
39:12And the goal of the sculptor, Oscar JW
39:14Hansen, was [music] to go ahead and
39:15provide something to what he called
39:17future visitors, and his [music]
39:19thinking was that we as human beings may
39:21not be here. He assumed that those
39:23future visitors would be able to read a
39:25star chart, and they could tell the
39:26position of the stars when they come to
39:28visit versus where they were in 1935,
39:30and be able to estimate how long ago the
39:32construction was finished.
39:35When construction ended, most men left
39:37to work on other dams, but many stayed
39:40to [music] work on the powerhouse and
39:41finishing touches.
39:44Unlike other construction camps,
39:46Boulder City didn't dry up. It remained
39:48a reservation until 1959
39:51when it incorporated.
39:53While alcohol was finally offered for
39:55sale in [music] 1969,
39:58Boulder City remains the only city in
40:01Nevada that doesn't allow gambling.
40:07Hoover Dam quickly became an
40:08indispensable component of the
40:10successful development of America's
40:12Southwest that had to be protected.
40:17On a hill above the dam are the remains
40:19of one of the gun emplacements built
40:21during World War II.
40:24As a supplier of power to defense
40:25plants,
40:26the dam was considered a primary
40:28military target.
40:30Since September 11th, 2001, [music]
40:33new and not to be disclosed security
40:35measures have been instituted in and
40:38around the dam.
40:43The structure itself has been remarkably
40:45steadfast since it was built.
40:47Over the decades, inspectors have walked
40:49the interior tunnels and marked even the
40:51slightest crack in the concrete,
40:54but none has proved significant.
40:59Large doors, similar to those inside
41:01submarines, were put in place to protect
41:03the power plant from a possible flood
41:06should one of the huge water pipes
41:07rupture.
41:09They have never been needed.
41:12One of the upgrades in safety technology
41:14is to add some additional earthquake
41:15sensors. We've experienced over 20,000
41:18earthquakes here at the dam and the
41:19power plants, the highest being a 5.6 on
41:22the Richter scale, with no damage to the
41:24dam, power plant, or any piping so far.
41:27People estimate that the dam is able to
41:29withstand an 8.6 on the Richter scale.
41:33While the concrete structure of the dam
41:34has remained virtually unchanged,
41:37the moving parts in the power plant have
41:38required maintenance and upgrades.
41:42Original turbine runners we had here
41:43were cast iron. They've got a life of
41:45approximately 40 to 50 years, so
41:48beginning [music] in the mid-80s, 50
41:50year into the life of the project, they
41:52replaced with the stainless steel
41:53runners. Up above the generator where
41:55all the electricity's produced,
41:57back at the same time in the mid-80s,
41:59we took [music] the old generator, which
42:00again, after 30, 40 years, insulation
42:03wears out, breaks down. [music]
42:05We did a complete overhaul of generators
42:07to then produce new outputs from about
42:1087 megawatts up to 130. So, we got quite
42:12a bit more power out of the same by just
42:14upgrading the unit.
42:18Water continues to be the dam's most
42:20precious commodity,
42:22and the US is not the only beneficiary.
42:25Mexico receives [music] 1.5 million
42:27acre-feet of water a year.
42:31While Hoover Dam does supply much-needed
42:33water, like all dams, it blocks the
42:35natural flow of a river
42:38and has an impact on plants and animals.
42:41More fish live here than ever could
42:42before, more animals, mountain sheep,
42:45birds, mountain lions, because [music]
42:47the one scarce element, the one thing
42:49that was missing from this environment,
42:50water.
42:52But altering the natural habitat has
42:54also led to the absence of many species
42:56within the Colorado River.
42:58Some native fish have found reproduction
43:00more difficult in the colder waters of
43:02Lake Mead.
43:06The engineers that designed Hoover Dam
43:08could not have foreseen all the ways the
43:10completed project would affect people
43:11and the environment.
43:16But judged by its original goals, Hoover
43:18Dam is a tremendous success story.
43:21From the close-knit [music] community of
43:22Boulder City
43:24to bountiful harvests in once-barren
43:26landscapes,
43:28Hoover Dam has changed the course of
43:30[music] a river and the course of
43:32people's lives.
43:34Here we are, almost 70 years after the
43:36dam was completed. The dam has never
43:39missed one single day of providing water
43:41or electricity to its customers, and
43:44some say we'll [music] still be here
43:45serving the public 2,000 years from
43:47today.
43:49I think it [music] symbolizes what the
43:51American people were about in that
43:54particular time in our history. We were
43:56moving to new frontiers, we were
43:58settling the West, we were
44:00building a nation, we were building a
44:03life, [music] and the attitude was, we
44:05can do this.
44:08The men who built Hoover Dam had not
44:11only accomplished what they set out to
44:12do, but created what has been cited as
44:16one of the seven engineering wonders of
44:18the world.

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