Thursday, January 10, 2013

Hoover Dam

[From Craig]  Hmmm, what can we say about one of the most-visited and photographed sites in America?  Well, it's not fiction, there definitely is a dam there on the Colorado River, in Black Canyon between Nevada and Arizona.  

The official descriptions say it's in Boulder Canyon, because the original surveys and justifications were written that way. By the time it was approved in 1928, the planners had decided to put it in Black Canyon but didn't want to upset the politicians by switching the name of the canyon.


The first thing we noticed when we drove up, was that the "high tension towers" closest to the dam were all really slanted, like electrical Towers of Pisa only more tipped. Looking at them further from a better vantage point, it's obvious that the angle is because they support wires that come almost straight up from the generator buildings below the dam, to the next towers high above. So the designers set them at the angle halfway between the source and destination.

We parked and went down to the security checkpoints that lead to the Visitor Center. There we learned we couldn't take in the nice lunch that Merikay had packed: no food is allowed past the checkpoint. This is an understandable policy in view of all the instances of exploding food that have occurred around the world, so we went back outside to eat lunch and walk the road across the dam.


We had lunch near these two statues of tall skinny eagles that were the largest bronzes ever cast in the US when they were made.  As you can see in comparison to the people, they are pretty tall.


We walked toward Arizona on the downstream side of the road. This is the view down the dam toward the generator buildings on each side. Water runs from intakes on the reservoir side through the dam to these buildings, where the generators make electricity for Los Angeles and surrounding states.  








There is a spillway like this on each side of the dam. (Everything about Hoover Dam is symmetrical between the Nevada and Arizona sides.) If the water in Lake Mead gets too high, it starts to spill over the right side in this picture. At first it just goes through that little grate on the bottom. But if it starts spilling fast it will go through the big hole in back. This happened big-time in 1982, which was the high-water year in Hoover Dam's history.


These are the intake towers on the Lake Mead side of the dam.  They take in water well below the surface, so that less dead fish and floating debris go through the generator turbines.



Near the dam, Lake Mead is pretty narrow and looks like the river that it is. Around the bend in back it gets much wider, and is a big recreation/boating area.  

The white bands around the water are calcium carbonate left behind by high water, especially in 1982 when the water was highest.


Next we walked back to the Visitor Center, and got through the security checkpoint now that our lunches were inside us. There we learned that of the three types of dam tours, only the shortest, least extensive one was available that day because the elevators down into the dam were out of order. If you come to Hoover Dam and are big fans of tours like Merikay and I, be sure you call ahead to make sure that the dam elevators are working!


As part of the "Visitor Center only" tour, we sat through several interesting presentations about how the dam was built. Thereafter we could go out on the Observation Deck from which we took this picture of the face of the dam. 


See how the dam is divided into 12 or more sections width-wise, and each of them is divided into many horizontal slices? Each slice is a single pour of concrete into a big form about 5 feet high, that averaged about the size of a city lot (thicker at the bottom, thinner at the top). After pouring each section, they went on to the next one across the dam, so that each section set at least 3 days before the next one was poured on top of it. Which amounts to about 3 years of continuous concrete-pouring!

Knowing something about California's earthquake bans against "unreinforced masonry", we were amazed to learn that there is not any rebar (steel reinforcing) in the main body of Hoover Dam. There is plenty in the intake towers, generator buildings, and other surrounding structures, but none in the dam itself. No way would California admit this dam into their state, if someone ever wanted to move it there!

Finally we went up to walk across the new bridge that goes across the river downstream from the dam, so that not all of the Nevada<-->Arizona traffic has to go across the dam itself. In a store later, we saw that they sold old postcards that showed an aerial view of the dam without the bridge, and new ones that were exactly the same view with the bridge.  The bridge is named for a local politician and for Pat Tillman, who was the NFL player who enlisted to go to Afghanistan in the middle of his career and was killed by "friendly fire" there.


They could not have designed a better place from which to take pictures of Hoover Dam! The rectangular array of white-froth spots in the lower river mark the outlets from the generator turbines. The cables you may be able to see just above the top of the bridge are part of the last remaining cableway that was used to pour the concrete in the dam.

We tried waving our arms from the bridge but couldn't see our shadows. It's quite a place!

From Merikay: My impression after seeing some of the enormous public works projects that were accomplished during and after the Great Depression is that government can and must do the big things.  Yes, six big private companies joined forces for the building of the dam, but without the government it would not have happened.  

Many of the improvements to our parks were also done during those hard times.  These programs saved many lives because they provided jobs for men who might otherwise have had none.  

I know there are probably to many people doing redundant office work for the government, but I would rather see more men and women working to build, restore and improve our country than in the military.  I would rather see more of our tax dollars going for infrastructure than for war.

It's all part of the big picture, and I'm glad we are getting to see it.

6 comments:

  1. Great photos of the Hoover Dam - one of my all-time favorite places to visit. It sure beats Las Vegas Strip as far as I'm concerned.

    Also, I agree completely with your comment on government projects. People sometimes seem to forget the tremendous accomplishment of well thought out building programs. How about the Interstate Highway System all we RV'ers use to drive around the country?

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  2. Very interesting tour and pictures, Merikay and Craig!

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  3. I'm so thankful we got to see Hoover Dam while we could still travel. The shadow of the bridge in front of the Dam is beautiful.

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  4. Having visited Las Vegas many times, we have made many trips to Hoover Dam and we still love it. About three years ago my mom, sister and I were there while the bridge was still being built.

    On our last trip we walked over the new bridge. Fantastic.

    So glad you went there and that you appreciated it.

    Hopefully you can go back for the dam tour.

    Susan

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  5. Great pictures. There is a dam museum in Boulder City. Small one and it cost a $1. I thought it was a better museum that taking the tours at the dam. You can add it to your list for next time.

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  6. Fascinating--I've been, but it was a short stop when I was 15 or so, never got to tour. And I'm with you 100% on the idea of federal employment. An excellent way to get important things done.

    Kris

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