Chattanooga Lock Project Reaches New Milestone
CHATTANOOGA, Tenn. (WDEF) – The ongoing project to replace the Chickamauga Lock has reached a significant milestone, with the delivery of the miter gate parts needed for the lock.
“These gates are hydraulic steel structures designed to handle high water pressure, control water levels, and allow recreational and commercial vessels to pass safely through lock chambers,” according to the U.S. Army Corps of Engineers.
The parts are being delivered between December 5 and 23, 2024.
“This milestone is a direct result of our greatest strength—our people,” said Lt. Col. Robert Green, commander of the USACE Nashville District. “The dedication, expertise, and teamwork of everyone involved in the Chickamauga Lock replacement project are the foundation of our success and the driving force behind this achievement.”
Cayce Grall, one of the project managers, explains the need for replacing the lock.
“Back in the 1930s and 40s, when the lock and dam were first built, engineers didn’t know about a reaction called alkali-aggregate reaction,” Grall said. “This happens when the alkaline in the aggregate reacts with Portland cement, creating an expansive gel. The gel causes the materials to grow, resulting in cracks and deterioration of the concrete. Over time, this has become a serious threat to the structural integrity of the lock and dam.”
The replacement lock will not only fix these issues but also improve functionality.
The Chickamauga Dam plays an important role in providing cooling water to the Sequoyah and Watts Bar nuclear plants.
Maintaining water levels ensures consistent power for areas as far as Knoxville.
Joseph Cotton, another project manager, talks about the economic benefits of the new lock.
“Approximately one and a half million tons of commerce pass through the lock every year, making it the second-largest lock in the Corps of Engineers system,” Cotton said. “We also see over 3,000 recreational vessels annually. Our latest economic analysis estimated $56 million in net benefits from this lock replacement project.”
“There are 14 pieces in total because the gates are so large,” Grall said. “Each piece weighs between 140,000 and 190,000 pounds. On the downstream end, there will be 10 pieces, with five stacked per gate. On the upstream end, there will be four pieces, with two stacked per gate. Together, these make up the full miter gates.”
The project managers confirm that the Chickamauga Lock replacement project’s final contract is on schedule to be awarded in August 2025, and the new lock is supposed to be ready by February 2028.
“One lock will remain in service throughout the entire project,” Cotton says. “The old lock won’t be decommissioned until we’re confident the new one works as designed.”
Cotton continues, referencing the history of the Chickamauga Lock.
“The Chickamauga Lock, built by the Tennessee Valley Authority (TVA) in 1940, is part of a partnership between TVA and the U.S. Army Corps of Engineers. Once the replacement project is complete, ownership of the lock will return to TVA. We value TVA’s continued maintenance of the Chickamauga Dam and their support in helping us decommission the old lock.”
He says, “This is about more than improving navigation—it’s about securing the future of a vital waterway for commerce and recreation and ensuring the long-term stability of the Chickamauga Dam.”
If you’d like to learn more about the project, you can click here.
