These are notes that I am writing to help me learn our industrial history. They are my best understanding, but that does not mean they are a correct understanding.
Wheeler Dam is a hydroelectric facility. It has 11 generating units with a summer net dependable capacity of 402 megawatts. Net dependable capacity is the amount of power a dam can produce on an average day, minus the electricity used by the dam itself.
To maintain the water depth required for navigation, the minimum winter elevation for the reservoir is 550.5 feet. The typical summer operating range is between 555 and 556 feet.
Wheeler has two locks, one 110-by-600 feet and the other 60-by-360 feet. They lift and lower barges as much as 52 feet between Wheeler and Wilson reservoirs.
Digtitally zoomed in on the left side of the above plaque
This plaque makes your appreciate the technology of the above plaque. I didn't bother to zoom in on the text because it was unreadable in person.
Southeastern USA has experienced a lot of rain at the beginning of 2020. In fact, we were driving up I-65 in Alabama the previous day in some pretty heavy rain. And all of the weather forecasters are quick to point out that the ground is saturated. The last column in this table is the cubic feet per sec that is passing through the dam.
So the spillway is passing a lot of water. I was surprised that only two of the 10 units were operating. (Note the TVA reference above says it has 11 units, but I can't figure out where the 11th unit is since it looks like they have five pairs of transmission towers.)
A satellite image shows that the powerhouse was designed for six pairs of turbines, but they fudged the design near the north end.
The South doesn't need as much power in the Winter because the air-conditioning demand is lower. In fact, when we were here the temperature was struggling to get into the 50s. But I would think TVA would shutdown the coal-fired plants so that they could run run all 11 units rather than waste water over the spillway. This reference does indicate that all turbines should be spinning before they raise any spillway gates: "If enough water can't be released through the turbines, it is sometimes necessary to let additional water flow through sluiceways or over spillways to speed up the drawdown and regain the storage space needed for future rains." [TVA-managing]
A closeup of the outflow turbulence of the spillway and the operating turbines.
While walking down a sidewalk along the overlook, I noticed some turbulence downstream of the offline turbines, especially near the bank. Do the valves leak that much water?
A view upstream of the dam. The river is wide. The dam providing a cheap bridge for the area has to be important for the economy.
My wife caught this photo as we headed across the dam.
The 110'x600' lock was constructed in the 1960s because blasting for the new lock caused the north wall of the original lock to collapse, which killed two people. The cause of the collapse was a thin layer of clay in the shale below the locks. That flaw in the bedrock created a disaster waiting to happen. The blasting triggered the disaster on June 2, 1961.
Steve Graham posted This aerial photo was taken after one of the original lock walls collapsed at Wheeler Dam on June 2, 1961. The new larger lock was under construction at the time. (The photo was taken by TVA photographer Orvel Dean.) You can use “Wheeler Lock failure” or “Wheeler Dam disaster” in your search engine to find articles and photos about the accident. You’ll also find information and photos about the massive Saturn rocket that had to be transported overland around the dam about two months later. It was built at NASA’s Marshall Space Flight Center in Huntsville and had to be moved ASAP by waterway to Cape Canaveral. Jay Smith: Hoarce Hamner was lock master when this occured the locked himself in the control room and refused to open lock gates as instructed by tva when the engineers came they confirmed he was correct and saved the dam and many lives. Pickwick Lock shared David Gulden shared Dennis DeBruler
Four TVA photos of the booster going over the new road and dock.
TVA posted November is a big month for Wheeler Dam! Construction began on Wheeler about 88 years ago on Nov. 21, 1933. While Wheeler was the second dam we built, it was the first dam to be built by TVA in Alabama. Wheeler is one of the nine reservoirs that create a stairway of navigable water on the TN River from Knoxville, TN, to Paducah, KY.
Steve Graham commented on his post Here’s a photo taken earlier with the water from Wheeler Lake still pouring over the upper end of the lock. The upper gates were open at the time of the accident. They had to let the water level in Wheeler Lake drop about 15’ down to the concrete sill in the days following the accident before the upper lock gates could be safely closed.
Steve Graham commented on his post
That June 2 collapse jeopardized NASA's shipment of the first Saturn I equipment from Marshall Space Flight Center to Cape Canaveral during August, 1961. Normally this barge would have made the entire trip down the Tennessee, Ohio and Mississippi Rivers, across the Gulf of Mexico, and up the Atlantic Ocean to Cape Canaveral.
To meet the test schedule for the Saturn for the race to the moon, NASA found another barge to finish the trip. "In its excessed fleet in Pensacola, Florida, the U.S. Navy had a barge used in World War II that would do the job. Teams from Marshall acquired the ship -- christened Compromise -- and quickly began modifying it to transport the rocket segments." [NASA]
In the meantime, TVA built a road from a new dock on the upstream side to a new dock on the downstream side on the south side of the dam. TVA posted four photos:
a new lock was going up on the Tennessee River. Work was under way on a second lock at Wheeler Dam, located between Florence and Decatur, Ala (RM 275). Dynamite blasts were set off daily at the new lock, spewing rocks throughout the site and shaking the ground. The new lock was being built near the north bank adjacent to the old wall. Crews of about 40 men were working through the night on that evening of June 2 to get the job done. Unbeknown to the workers and engineers, Wheeler lock had a fatal flaw. And the flaw that had gone undetected for four decades was about to bring the house down. A one-sixteenth-inch to three-eighths-inch band of clay lay beneath both the old lock and the new construction site. It was the same color as the shale layers above and below it – lying beneath the massive walls like a time bomb.
Looking at the first photo above, part of AL-452 is clearly the road built to the downstream dock. When I visited, this road was closed. I had assumed it was because of 9/11 security. But now I wonder if it was a temporary closure because of high water covering the fishing place and boat ramp.
Other goods such as grain were transloaded across the dam after the lock wall collapsed.
TVA
TVA posted four photos with the comment: "Did you know that Wheeler dam is one of nine reservoirs that create a stairway of navigable water on the Tennessee River from Knoxville, TN, to Paducah, KY? Construction was completed on this dam in 1936, and it first generated electricity in November of that same year. This dam is 72 feet high and stretches over 6,300 feet across the TN River!"
Justin Maness: They some mighty big catfish in those waters. Several 100+ been caught there.
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3 Scott Hicks: Setting the gate arms. James Heinske: There's always that one gate that won't close and make you do it all over again. I've worked on a lot of turbines, even some really big ones but,those gate arms are bigger than I've had to adjust
Screenshot, this video has some sustained white noise
Incredible site! Wilson Dam on the Tennessee River near Florence Ala., is releasing approximately 2 million gallons per second using all available generating units and 43 spillway gates. Heavy rainfall has resulted in very high river conditions along the entire 652-mile Tennessee River. We are storing water at dams in the tributary and main stem reservoirs to help reduce downstream flood levels.
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