Is Anyone Buried in Hoover Dam?

The most frequently asked question of tour guides at Hoover Dam is how many people are buried in the dam. Visitors are surprised to learn that the answer is none.

People like to believe in tall tales, legends and myths, and this seems to be the one for Hoover Dam. The story of workers being buried in the dam has been around for a very long time, it originated when Hoover Dam was being built in the 1930's. Tourists would come and watch the dam being built, and they felt compelled to humanize the dam by concocting wild stories about its builders and the hair-raising dangers they faced. One of these stories was the myth of men buried alive in the concrete. But this is just a story, and here is the proof:

Between the years 1922 and 1942, the total time for construction of Hoover Dam, a total of 114 men died. Of those, 37 died from being struck by an object like a falling rock, 28 died from falling off either the dam or the steep canyon walls, 14 died from heat prostration (before everyone learned the importance of drinking enough water while working in the hot desert heat), 10 died from accidental explosions, 9 died in construction traffic accidents, 6 men drowned in the river, 5 men were accidentally electrocuted, 4 died in a rock slide, and one man died when a form broke and concrete spilled out. All of the bodies of the men who died during construction were recovered, and no one was left buried at the dam site. With everyone accounted for, there was no one left to be buried in the dam. There is a bronze plaque at the dam which reads: "They Labored That Millions Might See a Brighter Day - In Memory of Our Fellowmen Who Lost Their Lives on the Construction of This Dam." This plaque was dedicated on May 30, 1935.

It would not have been possible for a worker to be buried in the concrete because of the way the dam was built. The dam was not built all at once, as that is far too much concrete that could be produced at any one time. Instead, the dam was built as a series of concrete blocks. These concrete blocks were typically 50 feet wide, 60 feet long, and only 5 feet high. In fact, the written contract required that these concrete blocks could be no higher than 5 feet. If you look closely at pictures of the front of the dam you will see horizontal lines at regular 5 foot intervals.  These are the tops and bottoms of these concrete blocks. A concrete block could not be placed unless the block beneath it had become hard enough to walk on. So the maximum depth of fresh concrete for anyone to fall into at any time would have only been 5 feet!

Concrete consists of sand, rocks (or aggregate), cement (which acts as the paste that holds everything together), and not as much water as you might think. This makes the concrete very dense. Imagine jumping onto a pile of sand or rock; you would only sink into it a couple of inches. The same is true with fresh concrete.  Typically, concrete has a density of 150 pounds per cubic foot, which means that a block of concrete that is one foot wide, one foot long, and one foot high would weigh 150 pounds. Water has the density of only 62.4 pounds per cubic foot.

In addition, the concrete blocks were built along side of each other as the dam was being constructed, so falling from one concrete block into fresh concrete in the next block would have only been 5 to 10 feet. There is no record of anyone falling into a concrete placement. In fact, if you look at pictures of concrete being placed into one of these blocks you will see men inside the forms working the fresh concrete. They were known as "puddlers," and their job was to use their shovels and feet to spread the concrete around and make sure the concrete completely filled up the form. These puddlers could easily walk on the fresh concrete because it was so dense that they would sink in only a couple inches. Concrete takes 12 hours to become hard, so there was no way for the puddlers to become stuck in the fresh concrete.

The concrete was mixed at what is called a batch plant, where plant workers would combine the sand, aggregate, cement, and water in the right proportions to make the concrete, mix it together, and fill a large bucket with the fresh concrete. The bucket would then be lifted by cables and transported across the canyon to the concrete block that was currently being placed. From there, one of the puddlers would direct the bucket to where it was needed, pull a lever and allow the concrete to spill out of the bottom of the bucket. It was his job to make sure that no one was under the bucket when it was opened. Even if a bucket did empty directly onto one of the workers, there were at least half a dozen other puddlers in the same block to dig him out. These buckets had the capacity of 8 cubic yards, which is approximately the same volume contained in a concrete truck you might see going down the road.  If a concrete block is 50 feet wide and 60 feet long and 5 feet high, you multiply these together to come up with a total volume of 15,000 cubic feet of concrete in each block. There are 27 cubic feet in a cubic yard so if you divide 15,000 by 27 you come up with 556 cubic yards in a concrete block. If you divide this 556 cubic yards by the 8 cubic yards in the bucket, you will see that the bucket has to make almost 70 trips just to fill up one of the concrete blocks! Imagine how much concrete would be in 70 concrete trucks and you get the idea. There is a total 3,220,000 cubic yards of concrete in Hoover Dam, and if you divide this number by the 8 cubic yard capacity of the bucket, you see that these buckets had to make 402,500 trips to build Hoover Dam! Imagine 402,500 concrete trucks, and you have got yourself another Hoover Dam!

If you would like to read more about it, an excellent book on the construction of Hoover Dam is entitled "Hoover Dam, An American Adventure" written by Joseph E. Stevens and published in 1988.  Pages 219 to 221 and page 294 talk about how there is no one buried in Hoover Dam.

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