All I knew before the Grand Canyon excursion about Hoover Dam, which was part of our visit, is that the dam connects two states: Nevada and Arizona.
More, in fact, I did not read anything about it, the dam and the dam.
But, being on the dam itself, I will say that it, nevertheless, strikes the imagination.
Hoover Dam, or Hoover Dam. Later, after reading about it, I realized that this dam is a rather serious structure, it is not without reason that it is recognized as a historical landmark and a national architectural monument of the United States.
It is one of the tallest dams on the planet and one of the most powerful hydroelectric power plants in America.
There are many wonderful photos of this gigantic structure on the Internet, but they did not let us down, and all we could do was just admire the dam from above, from the bridge, on one side of which is the state of Nevada, and on the other side is the state of Arizona.
The day was very sunny, my photo of the dam looks like this.
A huge structure has held back the Colorado River for over 80 years, it was built between the Black Canyon ledges, from a height it seems that it squeezed into this narrow space, where it holds the pressure of the river.
Height - 221.4 meters.
The length is 379 meters.
Height above sea level - 376 meters.
Width at the base - 200 meters Width at the top - 14 meters.
The volume of the dam is 2,480,000 m3.
Weight over 6,600,000 tons.
The capacity of the spillway is 11,000 m3 / s.
The view is arched-gravity, in the form of a half-ring directed towards Lake Mead, which makes it possible to more efficiently distribute the water load. The water pressure at the bottom of the dam is about 220 tons per square meter.
As usual, the construction of the dam was conceived for many reasons: it was necessary to solve the issue of irrigation of the land for agriculture, to stop the flooding of the Colorado River, and, in the end, the constructed hydroelectric power station had to provide a lot of electricity.
The construction process for Hoover Dam was planned to begin in 1931 and be completed in 1938.
However, the large-scale project was completed already in 1936, 2 years earlier.
In those days, such a structure challenged the most advanced technologies.
Environmental conditions, when the air temperature often reached 50C, the need to change the course of the Colorado River during construction, and a host of other inconveniences posed serious challenges to engineers and designers.
So, for example, it was impossible to simply pour concrete into a large formwork, since at ambient temperature the entire structure would freeze for about 125 years!
In addition, the process of "setting" and "hardening" of concrete in such a large volume would inevitably lead to its cracking and destruction.
Naturally, neither the concrete hardening period, nor its quality at the output of the developers satisfied.
A unique engineering decision was made - to assemble the entire giant reinforced concrete structure from separate blocks.
All blocks were of the same height, about one and a half meters.
But the rest of the dimensions changed depending on where the block was located. The maximum block size was 18 m2 (at the bottom of the dam) and the minimum was 7.6 m2 (at the top). Inside these blocks were steel pipes with a diameter of 1 inch (about 2.5 cm), through which ice water circulated. This made it possible to create conditions for the correct hardening of concrete.
As a result, a very high-quality concrete block was obtained, reinforced with pipes, which also connected the blocks to each other. By the way, the total length of such pipes was 937 km.
After the block had solidified, the pipes were filled with concrete and the next block was cast. Thus, a single monolithic structure was created.
In 1995, studies were carried out to prove that Hoover Dam concrete was still gaining strength.
Compressive strength is generally outside the standard range for widespread concrete.
To change the course of the river and divert water from the work site, 4 tunnels were drilled in the mountains (two on each side of the river), each with a diameter of just over 17 meters and a total length of about five kilometers.
The walls of the tunnels were filled with 90 cm thick concrete. Therefore, the effective diameter was reduced to 15 meters.
At the end of the dam construction, these tunnels were not blocked. That is, they are still in operation, which in turn gives the dam stability and reduces the load.
The energy of water has found its application in hydroelectric power plants.
On October 26, 1936, the power plant gave the first electricity.
Today, the total capacity of 17 generators is 2080 MW.
From interesting facts: at the same time, thousands of people worked on the construction of the dam, but the maximum was recorded in June 1934. Then 5218 people took part in the construction. In total, about 21,000 people worked on the project.
About 112 people died for various reasons during the years of construction, but who takes into account the human losses during such gigantic construction projects.
Since the tour of the dam was not included in our trip, we walked along the bridge, on which there was just a scorching sun, and left in our memory these are our shadows.
To be continued.
All photos and videos are copyrighted.
Read other articles about the USA here:
Las Vegas, part 1.
Las Vegas, part 2. Large M & M's store in Las Vegas.
Las Vegas, part 3. Hotel HOOTERS.
Las Vegas, part 4. City walk.
Las Vegas, part 5. City walk (continued).
Las Vegas, part 6. Excursion to the Grand Canyon, Arizona.