Building the Hoover Dam | The B1M


On it’s completed in 1936 this was the largest
concrete structure ever built. The incredible feat of engineering played
a critical role in the development of the American Southwest during the early 20th century, providing flood management, hydro-electric power and securing a reliable source of water
for millions. This is how the Hoover Dam was built. With plans around since 1900 to harness the power from the mighty Colorado River, it wasn’t until 1928, that the United
States Congress authorised the project and initial surveying began. With the onset of the great depression just
a year later, the project was seen as a way for the government to provide much-needed
jobs in the American southwest, which had been experiencing a population boom prior
to the stock market crash. Located 26 miles southwest of Las Vegas, on
the Nevada-Arizona border, the project required a vast number of workers and their families
to relocate – and an entire new town was established. Owned and run by the government, Boulder City
was to be a model for the rest of the country to follow in the dark times of the depression. To drive the project’s progress, President
Hoover ordered construction of the dam to start in May 1931 – before the necessary infrastructure
at Boulder City was in place – and many workers lived in temporary tents in what became dubbed
Ragtown. To escape the harsh living conditions, many
workers began to frequent the then small outpost of Las Vegas, driving significant growth and earning it a reputation for gambling and adult entertainment. Though living conditions were poor, work began
on diverting the Colorado river so that the dam could be constructed on the dry riverbed. To divert the waterflow, four 56 foot, 17
metre wide diversion tunnels (two on each side of the river) were bored through the
canyon using nothing more than dynamite followed by workers using pneumatic jackhammers. Excavated rock was then dumped into the Colorado
River, creating a cofferdam that forced water to flow through the newly constructed tunnels. A second cofferdam downstream prevented water
flowing back into the construction site and formed an area that could be pumped dry,
exposing the river bed. The Hoover Dam employs a gravity-arch design
and is held in place by the weight of its concrete together with the pressure of the
water it holds forcing it into the canyon floor and walls. Such a principle required the canyon surfaces
to be smoothed as one of the first activities, to prevent leaks. It was during this phase of the project that
the first hard hats began to be used. Workers dipped their hats in tar and let it harden,
protecting them (at least to some extent) from falling debris. Seeing their success,
the project’s leaders quickly ordered thousands of these hats and mandated their use by the workers. In 1933 – some 18 months ahead of schedule
– the first concrete pours began on the dam. As concrete gives off heat and contracts as
it cures, a project on the scale of the Hoover Dam would have taken more than 125 years to
harden if poured in a single continuous pour and structural weaknesses would have caused
the dam to crack under its own weight. Instead, the site was divided into a series
of rectangle moulds, some as large as 50 square feet (or 15 square metres) in size. These moulds were fitted with a series of
steel pipes that carried river water through them, allowing the concrete to cool and harden
much faster than if it was left to do so alone in the heat of the desert. Once the concrete had hardened and stopped
contracting the pipes and hairline cracks between neighbouring blocks were filled in with grout
and a new layer of moulds was placed on top. This process was repeated time and again to
build the dam walls. As the dam steadily rose, getting the concrete
to where it had to go before it began to harden started to pose a significant challenge. To overcome this, an ingenious system of overhead
cables that carried buckets of concrete from specially built concrete plants on the Nevada
side of the dam to the required location on the construction site was used. In total, 87.5 million cubic feet of concrete and some 582 miles of cooling
pipes were used in the construction of the dam. By 1935 – two years ahead of schedule – the
726 foot high dam was complete and the river diversion tunnels were sealed shut, allowing
the Colorado to begin flooding the canyon behind the structure and creating the reservoir
that we know today as Lake Mead. Fit out of the adjacent power plant and its
associated infrastructure took place in parallel with construction of the main structure – and
the dam began generating electricity at the end of 1936. Today, this remarkable infrastructure project
has an average output of 4.2 billion kilowatt hours and provides water and electricity to
millions across the southwestern United States. An economic catalyst to an entire region of
North America and a powerful example of the impact that our industry can have. If you enjoyed this video and would like to get more from the definitive video channel for construction, subscribe to The B1M.

100 thoughts on “Building the Hoover Dam | The B1M

  1. Images don’t give you a perspective of the sheer enormity of it. I live not far from Las Vegas and have been to the dam a few times. It’s a truly incredible piece of engineering especially when you consider when it was built. Awesome video. Could’ve used even more detail imo in relation to the fatalities during the construction etc.

  2. Hit a couple of remote control passenger planes into it part of another false flag inside job like 9/11.

  3. A national inspiration during the dark hopeless days of the Great Depression in the United States, great infrastructure can be great in many more ways than just physical ones.

  4. The logistics and engineering are amazing. Especially considering this was built nearly 100 years ago.

  5. The government doesn't give a shit about this problem. We had two hundred Billion-Jillion gallons of EXTRA water (called Floods) in the Midwest, during May-Jun 2019 The government will help you pump oil across America, but no one pumps water to areas of drought. What's what wrong with that picture…?

  6. Back in the day the US government still invested in infrastructure was apparently 1931…

  7. I'm glad that I got to travel across it before they closed it to public use. I hauled produce from Nogales Az to Vancouver B.C. and drove my truck across it many times. It sure gave a great view sitting up in the truck. Beautiful!!

  8. Ah, so this is where i led the NCR to victory and flung lee oliver off! good history lessen

  9. It would be interesting to know about the environmental impact of the dam.

  10. I think it was called Boulder dam originally and then changed to honour President Herbert Hoover in 1947.

  11. WHY didn't they hire an AMERICAN Narrator????? Rather than some FOREIGNER. Who made that decision? Probably another FOREIGNER. What happened to PATRIOTISM in this Country?

  12. Unfortunately a project of this scale and significance would not be possible today because of the endangered spotted moth. Even though it creates clean electricy and drinking water for millions.

  13. Shame you couldn't find time to honour those who lost their lives on this project. Jeremy Clarkson does a much better job in his book "I Know You'Ve Got Soul". Try harder.

  14. The pinnacle of US engineering. Built by bare hands, real men who dared to go beyond and above. It won't be remotely possible today, given the feminine hormones the melting men carry today or not without pissing few groups, and protesting whiney bunch of MFs about equal representation of colors instead of zeal.

  15. Know he wanted to end on a high note but he should have mentioned something about the deaths involved. Pretty sure it was more than any other construction site in the US then or since but don't quote me on that.

  16. Oh man, the story is so fascinating. hats off to the people who made this possible.

  17. MISTAKE! MISTAKE! MISTAKE! MISTAKE! MISTAKE! MISTAKE!
    "Average output of 4.2 billion kWh". This should say…
    "Annual output of 4.2 billion kWh".
    kWh is a unit of energy not power. You need to quote how many kWh are generated in a year. Or state the average power output, which equals about 2018 MW (installed capacity).

    I love the B1M channel but get tired of technical people who get confused between Power (kW) and Energy (kWh).

  18. How do they harness the power that is generated for the people? Batteries?

  19. aaaaaah back when the whole crew was actually working not just 1 or 2 guys working their ass off while the rest just stand there not doing anything lol ??

  20. I was a dam builder
    Across the river deep and wide
    Where steel and water did collide
    A place called Boulder on the wild Colorado
    I slipped and fell into the wet concrete below
    They buried me in that great tomb that knows no sound
    But I am still around
    I'll always be around and around and around and around and around ??

    The Highwaymen – Highwayman

  21. 4:22 You say "fifteen square metres". Nup, it looks more like "fifteen metres squared".

  22. What would happen if the hoover dam collapsed.? What would happen to Las Vegas and such?

  23. At a time when USA was the best country I'm the world.

  24. OMG ..what a beautiful well done amazing job!!! I was there in 2000 and it still takes my breath away… unbelievable when everything was so difficult to built because they did not have so much of the power tools like today..so much work and so much heat because Arizona and Nevada is so hot in the summer and so cold in the wintertime..hard hard labor..poor people ..And done to perfection.Until today its still standing strong. Great strong Heroes!!! They sure have a special place in heaven.Today's roads and streets are a mess, today they use asphalt instead of concrete..Lol and it takes them years to only patch the pot holes….

  25. Dude they could have used a potion of swiftness so it could go by faster

  26. Yep! So many died due to the rapidness. They did not even get proper burial. When someone died, no attention were given by saying that “He is dead and good for nothing at all.” Browse history and you will find the dark side this “ENGINEERING MARVEL” as well.

  27. That was the time when America was constructing dam with dynamite but now destructing the world with bombs.

  28. Super iam very interested so please send me how a hydraulic turbine work and their phenomenon to generate electricity

  29. Is this that evil patriarchy of toxic masculinity you hear feminist bitching about?

  30. Probably the classiest project the B1M ever undertook.
    The look of the area, with stone walls on the cliffs held
    in place over the roads with vintage heavy chains. The
    awesome art-deco style of the overall architecture, the
    quality of the craftsmanship and the quality of the
    concrete itself, still hard and smooth from the day.
    And the brute size of this idea – what were they thinking?
    It cannot be made today in America.
    The generation needed just doesn't exist anymore.

  31. This was also due to hydroelectric scheme design and not just civil engineering! Great video as always

  32. World today needs that old progressive America and not today’s America who is a mastermind of every global war and terrorist organisations.

  33. Government projects for capitalism! The school system was meant to turn out educated workers but it doesn’t do so good nowadays, Even though we spend among the top industrialized nations per capita

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