Monday, February 27, 2017

Chickamauga Dam in Tennessee River in Chattanooga, TN

(3D Satellite)
While studying "Tenbridge," I discovered this dam.
TVAdam
The 60-by-360-foot lock at Chickamauga lifts and lowers river craft about 50 feet between Nickajack and Chickamauga reservoirs. [TVAdam]

GeoCaching, construction started in 1936 and it began operations in 1940
TVAprevent

Barry Thornberry posted
"Construction on Chickamauga Dam"

TVA posted four photos with the comment: "Chickamauga Dam is 1 of 9 Tennessee River dams located just north of Chattanooga. Chickamauga continues its 82 years of service this month by providing clean, low-cost energy, along with flood control, navigation, recreation, and water quality. All things that make this region a great place to live, work, and play!"
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Matt Dillon commented on TVA's post, cropped

Deep Zoom has some more construction pictures.

Dennis Sayles posted
August 1942. "Tennessee Valley Authority. Generator hall of the powerhouse at Chickamauga Dam. Located near Chattanooga, 471 miles above the mouth of the Tennessee River, the dam has an authorized power installation of 81,000 kilowatts, which can be increased to a possible ultimate of 108,000 kw. The reservoir at the dam adds 377,000 acre-feet of water to controlled storage on the Tennessee River system. The power that goes out over its 154,000 volt transmission line serves many useful domestic, agricultural and industrial uses." Acetate negative by Jack Delano for the U.S. Foreign Information Service. 
https://www.shorpy.com/node/27186
Ralph Young: 138000 volt transmission if it’s tva. Been by Chickamauga many times. Tva has a nice park below the dam.
Kai Schwarz: I'm curious about what those two big cylinders are to the left of the panel. They look like really big capacitors, but that can't be right?
Justin Yochum: Kai Schwarz those are hydraulic accumulators. The cabinet he's sitting in front of is the governor that houses all of the mechanical and hydraulic components for controlling the unit.

The dam was designed in a way that allowed a larger 110 feet (34 m) x 600 feet (180 m) lock to be installed if increases in river traffic ever required it. [GeoCaching] I noticed when I looked at the satellite image that the lock seemed rather small. I confirmed that it can pass only one barge at a time instead of the 9 that a 600x110 lock can pass or the 15-barge tow that a 1200x110 lock can handle. I also noticed the cofferdam big enough for a new lock, but no other signs of construction. In fact, construction stopped in 2012 and the batch concrete plant was removed because of a lack of funding. [TimesFreePress2016] But in this case a new lock is also needed because the old one is falling apart faster than normal. It suffers from "concrete growth:"
Chickamauga Lock has growing concrete in it's structure, which is a reaction between the alkali in the cement and the minerals in the stone. This growing concrete has brought many problems – in some places large chunks of concrete have broken loose from the lock walls – and because the massive blocks that make up the lock have expanded at different rates, the top of the structure is uneven. Lengthwise, the lock has actually grown five inches inside the lock chamber. The approach walls have grown even more. Corps of Engineers and TVA working together continues making temporary repairs to the project spending large maintenance dollars. Corps and TVA have determined that Chickamauga Lock does have a finite life. [usace]
This has caused problems that have shutdown the lock completely such as "a crack in a steel support beam on the upper gate" in 2014. The government is having to waste a lot of money doing serious maintenance work on this like every year the new lock is delayed. [TimesFreePress2014] Fortunately for the eastern Tennessee economy, congress has chosen to fund the Olmsted Dam cost overruns out of the general fund so that money from the Waterways Trust Fund can be used to replace other locks in the nation such as this one and the Kentucky Dam Lock. This PDF file describes both the Kentucky and Chickamauga Lock projects. Of note is the "cofferdam stabilization." Does it need to be stabilized because it has set for four years or because that would have been the next phase of construction anyhow? The USACE also has a page concerning the new lock construction.

Note above that GeoCaching indicated the dam was designed to allow a bigger lock to be built. I have to wonder if the current design was the one that was envisioned in 1936. It seems dangerous to remove about a third of the spillway capacity. Or maybe they don't need as big a spillway now that more dams with flood control reservoirs have been built upstream.


I'm reminded that this is a TVA dam because, like the Kentucky Dam, I'm having a hard time figuring out how the spillway gates work. This is my current best guess.

Looking at Phil Thach's photo and the ones below, it appears there are two sluice gates in each bay, one on top of the other. They normally raise the upper gate and let water squirt out between the two gates.

TVAprevent
Note that there are no gates in the side rail. This must be a construction photo taken before they installed the gates, and we are looking at the normal river flow passing through the spillway structure.
TVAprevent
Nate Morello posted three photos. The one in the foreground is a MLC300 and the one in the background is a 999. The site also has an 888.
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Keldon Corbin Davis posted
Ben Stalvey Neat MLC 300 hard at it
Keldon Corbin Davis Ben StalveyAECOMS getting started on the lock project at Chickamaga lock and dam TN
Jim Paris This irritates me to no end! I am a firm believer in NOT overlifting. There is no reason ( from this picture) for that tug to be that high in the air!
Jim Browne Its a cool pic but that was my first reaction. "Why is it so high up?"
Gordon Veitch Every time i have seen these boom’s erected i feel they are going to snap such a sag but up to now none
Gordon
Keldon Corbin Davis Gordon Veitch carry a little belly don’t they lol

Nashville District posted three photos with the comment: "#Construction work continues on the Chickamauga Lock Replacement Project on a beautiful day on the #Tennessee River! 📸 Lee Roberts #NashvilleCorps #USACE"
Ben Stalvey shared
Nice Manitowoc MLC 300 hard at it...
Ron Jewell III: Dont forget the 999 in the back
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Josh Hendon posted

Josh Hendon
Ben Stalvey: Sweet MLC 300 where is this? Cool shot.
Josh Hendon: chicamauga dam Chattanooga TN

Worldwide Railfan Productions posted
NS 170 departing Chattanooga, TN across the Tennessee River and the TVA hydroelectric dam. ~drawbar
[Since a couple of the gates evidently don't work, we can see how far open the other gates are.]

Note the dam in the background.
NS Locomotives , Equipment and its Predecessors posted
Train 952 on Tenbridge.

In this view we can actually see the lock wall being constructed.
NS Locomotives, Equipment and its Predecessors posted
Three yeas ago , the PC heritage unit lead a short office car train into Chattanooga Tn.
[That is the Tenbridge in the left background.]

A nice view of the gates:
E.m. Bell posted
A couple of fisherman try thier luck as NS 282 leaves town Northbound. 3rd district of the CNOTP
 
Nashville District posted
Here's an amazing view from a tower crane sitting high above the new Chickamauga Lock Replacement Project as well as the existing 360-foot by 60-foot Chickamauga Lock currently in operation.  Construction of the new lock is occurring inside a large coffer dam adjacent to the lower approach area of the existing lock. The new lock will be much larger at  600-foot by 110-foot, which is the predominant nationwide dimension for most (not all) locks around the nation. 📸 Jeremy Breese
Pickwick Lock shared
Bird's Eye view of Chickamauga Lock in Chattanooga with the ongoing construction of the new 600 ft. x 110 ft. lock chamber.
Chickamauga Lock posted
Great view from the top of the yellow tower crane! Thank you Jeremy Breese.
Fort Loudoun Lock shared [Has the same comment as the Nashville District.]

Thomas Gurley commented on Chickamauga Lock's post
Here’s one of you Jeremy Breese!

1 of 3 photos posted by BradleyDCC
Former N&W High Hood SD40 NS 1580 coming across Tennbridge this [Mar 10, 2024] evening on NS 171 en route to TVRM…what do you think, should we model this unit?

Screenshot
October rainfall in the Tennessee River Valley was nearly 180% of normal with 5.26 inches. Normal for the month is 2.95 inches.
For the year, the Valley has received 55.34 inches of rainfall, that's about 13 inches of surplus and just over 4 inches more than we would typically see in a year - and it's just the beginning of November.

Alamy has 102 pictures of the dam including several with the gates at flood stage and completely shut

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