Thursday, May 6, 2021

1967 TVA 107netMW Nickajack L&D replaced 1913 Hales Bar L&D at New Hope, TN

Nikajack: (Satellite)
Hales Bar: (Satellite, just the lock and powerhouse is left)

I discovered the Nickajack Dam while researching the bridge at New Hope. This town is so close to I-24 that I need to check it out during my next trip to Florida. Although I read that the visitor center is closed.

The Nickajack Dam replaced the Hales Bar Dam in 1967 because the TVA could not permanently stop the leaks under the Hales Bar Dam.

TVA
[The dam is 81' high and 3,767' long. It has a 600' x 110' lock and the foundation for an 800' lock. The four generating units have a summer net dependable capacity of 107 MW.]

The Hales Bar Dam as built. Tainter gates were added during 1947-48 [mst, p32,37] and an extension was added to the powerhouse. Note the steamboat headed into the lock. 
tagcaver
This reference also has a lot of construction photos.

TVA posted six photos with the comment:
Dam Spooky!
Hales Bar Dam, constructed between 1905 and 1913 by the Chattanooga and Tennessee River Power Company, was the first multipurpose dam on the Tennessee. It is also known as one of the most haunted dams in America. Ghost hunters say there are lots of reasons why Hales Bar is haunted, ranging from a Native American curse to a tunnel collapse resulting in the death of children. It is a mishmash of truth and legend.
The spooky story: 👻http://tva.me/qGhJ50Gznwg
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tagcaver and Jenni Fankenberg Veal, Oct 2020
[The coal fired power plant in the background was built in 1922-24. [mst, p22]]

When you do a Google search for "Hales Dam," you get a lot of hits about it being haunted. I don't care about ghosts, but I do care that it "was the nation’s first hydroelectric dam." I thought that the Keokuk Dam on the Mississippi was the first. This dam must of just beat Keokuk because this one was done in Nov, 1913 and the Keokuk Dam also finished in 1913. Keokuk makes a lot of claims such as being large and being the first to use high-voltage transmission to its market (St. Louis), but it doesn't claim to be the first. The market for the electricity from this dam was Chattanooga. The limestone and shale bedrock under the Hales Bar Dam started leaking soon after it was completed. In addition to hydroelectricity, the dam was built to tame one of the major impediments to year round navigation, specifically, the Tennessee River Gorge. Until the gorge was drowned by this dam, there were significant whirlpools. Some were so big and permanent that they had names. [Tata & Howard, tagcaver] "It was 113 feet high, 2,315 feet long and its spillway had a combined discharge capacity of 224,000 cubic feet per second. At that time it was one of the first major multipurpose dams and one of the first major dams to be built across a navigable channel in the United States. The dam was estimated to cost only $2 million but by the end it was nearly $10 million, which equals $237 million in today’s value." [tagcaver]  The cost overrun was caused by the bad foundation provided by the limestone bedrock.

mst, p13
"41 ft lift lock on the right (west) bank of Hales Bar Dam was the first built across a navigable river in the USA, as well as being the highest when it opened in 1913. Just 265 ft long, it soon became the shortest lock on the Tennessee River."

mst, p15
"The project required congressional approval because it was the first time a private power company constructed a major dam across a navigable channel in the United States! Soon after completion wooden flashboards were tacked into the crest to increase the operating pool from 636 to 639 ft, shown here in the 1920s."

When the TVA bought the dam in 1939, they were able to stop the 1000 cfs leaks by 1943. But in the 1950s it started leaking again at 2000 cfs. "Dye traces in 1960 suggested that many of the leaks were interconnected and there was an increasing chance that the entire dam could fail." Rather than spend money on a bigger lock and fixing leaks, in 1963 they decided to use that money to help build the replacement dam 6.5 miles downstream. The name Nickajack comes from the former Cherokee Indian village and cave that got flooded by the new dam. [tagcaver]
tagcarver and mst, p45
[The 1000' wide spillway was dynamited during 1967-68 to remove it as a navigation hazard. Note that the lower pool has filled to the same height as the upper pool. The steam generating power plant had already been removed in 1965.]

Tata & Howard
"The Hales Bar Dam old hydroelectric plant is now used as a dry dock"

Jenni Frankenberg Veal, Oct 2020
[Boats are stored dry on the old turbine level. [tagcaver]]

In fact, the boats are stored in racks.
mst, p47

Not only has the powerhouse been repurposed as a dry dock, the lock has been repurposed as a barge loading dock.
Satellite

JanAndPat

When the Hales Bar Dam was built, they chose the most narrow part of the river assuming that it was narrow because the rock was strong and resisted erosion. Unfortunately, they built the dam on top of a limestone cave system. The problem is not the open cavities, they can be filled with grout. The problem is the clay filled cavities because they keep the grout out, but then they erode away after a grouting project increases the hydrostatic pressure. So why was the Kentucky Dam built on a cave system? Probably because they could not move a few miles away to avoid the system since a good part of Kentucky is a cave system.
mst, p2

TVA-replacement
"Construction began on Nickajack in 1964 with initial power operations occurring in February 1968. TVA built the two navigation locks first, thereby assuring a steady flow of barge traffic. All salvageable parts—such as gate locks, spillway gates, and generators—were moved from Hales Bar and repurposed."
[This is not the only source that claims that two locks were built. If so, why do we now have just a foundation for an 800' lock? Especially since 800' won't improve the handling of the standard 15-barge tow.]


This is one of several photos on the indicated web site that must have been taken during a tour of the dam. This is the equipment that raises and lowers the tainter gates.
JanAndPat

Fort Loudoun Lock shared three photos.
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TVA posted three photos with the comment: "Nickajack Dam on the Tennessee River was built in 1967 to replace the privately built and notoriously leaky Hales Bar Dam near Chattanooga. As we continue to invest in carbon-free energy, Nickajack unit 3 is getting some upgrades to its 50-year-old generator. Once returned to service, unit 3 will join the other three generating units producing up to 107 megawatts of renewable energy! "
James Torgeson shared
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TVA posted three photos with the comment: "Check this out! The generator rotor and the exciter bridge are being lifted for installation at Nickajack Dam on the Tennessee River. 👇😯 The dam's unit 3's is being overhauled  so it can continue making clean, renewable energy for decades to come. "
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A 21:19 video of the Hales Bar Dam. I didn't watch it because urban exploration videos rub me the wrong way.






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