By Lee Roberts
NASHVILLE, Tenn. (Oct. 16, 2023) – The U.S. Army Corps of Engineers Nashville District showcased two of its mega construction projects on the Tennessee River and its hydropower rehabilitation efforts at Barkley Dam on the Cumberland River last week to the assistant secretary of the Army for Civil Works.
Lt. Col. Robert W. Green welcomed Michael L. Connor to the Chickamauga Lock Replacement Project in Chattanooga, Tennessee, the morning of Oct. 12. Stacey Brown, deputy assistant secretary of the Army for Management and Budget, also visited and toured the project.
Connor received project updates, toured the active lock, and overlooked where Nashville District’s contractor, Shimmick, is constructing a 600-foot by 110-foot navigation lock chamber and has placed more than 200,00 cubic yards or about 80 percent of the concrete required to complete the project. He also looked at work barges on the upstream side of Chickamauga Dam where the contractor, C.J. Mahan, is placing tremie concrete into drilled shafts on the bottom of the river to anchor the piers for the upstream approach walls.
Elizabeth Burks, Nashville District Integrated Projects Office chief; Resident Engineer Tommy Long, Project Manager Capt. Joseph Cotton, and Lockmaster Cory Richardson briefed Connor on current navigation operations, the $245 million lock chamber contract, $60.9 million upstream approach wall contract, Joint Risk Register success, and scope of future downstream approach wall and decommissioning contracts.
Connor noted at Chickamauga Lock that visiting projects helps him realize the challenges that Corps of Engineers districts and contractors face with construction projects. He added that interacting with engineers, project managers, and contracting officials builds a greater understanding of the issues that helps him with communicating why projects cost so much, and the benefits of looking for more efficient ways to contract and complete projects.
“The thing you can’t get from briefings and trying to deal with the budget issues and everything else is the complexity of these projects, and the contracting that we have to do and how doing that in different ways can affect the overall financial aspects of the project,” Connor said.
Connor boarded a Blackhawk helicopter midday from the 101st Airborne Division’s Combat Aviation Brigade at Fort Campbell, Kentucky, for an aerial tour of the Tennessee Valley Authority dam projects downstream and the navigation locks on the Tennessee River that Nashville District operates and maintains.
In the afternoon, he toured the Kentucky Lock Addition Project in Grand Rivers, Kentucky, where the contractor, Thalle, is constructing the lock chamber for the new 1,200-foot by 110-foot navigation lock.
Burks and Resident Engineer Jeremiah Manning, Project Manager Bob Winters, Area Manager Mike Looney, and Supervisory Navigation Facility Specialist Caleb Skinner briefed Connors on current navigation operations, the $380 million lock chamber contract, and scope of future downstream approach walls, lock electrical and mechanical features, lock operations buildings and bridges, and site restoration contracts.
The larger lock is under construction because more than 26 million tons of commercial cargo and goods valued at more than $10 billion pass through Kentucky Lock annually. The average delay for commercial tows through the 600-foot active navigation lock exceeds 10 hours, some of the longest delay times in the system. Tows that are greater than 600-feet have to perform a time-consuming double lockage, which contributes to the lengthy delays. While the old lock can hold nine barges, the new lock will accommodate 15 barges.
Burks explained how the existing lock is too small to meet current and future traffic demands without significant delays, and that the Corps of Engineers has remained resilient through inflationary impacts, labor increases, and supply chain issues to keep the construction project moving forward.
Connor saw the active lock and walked the full length of the ongoing lock chamber construction site, stopping at different points for specific project updates.
The next morning, he visited the nearby powerhouse at Barkley Dam on the Cumberland River to see ongoing rehabilitation work of the hydropower units, which includes the rotors, turbines, and associated equipment.
Powerhouse Superintendent Jamie Holt explained that the staff takes a lot of pride operating and maintaining the hydropower plant and how the project’s four units are capable of producing 140,000 kilowatts of hydroelectricity supporting peak demand in nearby communities in the region. The plant’s mechanics and electricians provide preventive and corrective maintenance, while operators run the units for cheaper green power.
“A generator produces 13,800 volts. It runs out to our switchyard, and it is stepped up in voltage to 161,000 volts,” Holt said. “After the upgrades we’re going to increase from 140 megawatts to 180 megawatts.”
Barkley Powerplant started operating in early 1966 when the first of its four units were placed online. Each of Barkley’s four generators is capable of producing 32,500-kilowatt hours. In a typical year, the plant produces enough hydroelectricity to power over 30,000 homes. Most of the equipment in the plant is original and has been operating more than 50 years, making it difficult to find replacement parts and to upkeep the units.
The ongoing Hydropower Modernization Program authorized under the Section 212 of the Water Resources Development Act of 2000 is making it possible to bring the generators up to date and to operate them more efficiently.
Loren McDonald, Nashville District’s Hydropower Support Branch chief, said the Section 212 Program made it possible to enter into agreements with the Southeastern Power Administration, and power preference customers, to reinvest revenues into updating the main powertrain components in the Nashville District’s nine hydropower plants in the Cumberland River Basin.
“Our system on average is 63 years old and up until the last few years have had no major rehabs,” McDonald said. “For Section 212 we have 22 active projects going on across the district right now at $250 million dollars.”
The Hydropower Program supports all of the hydropower plants and 28 hydropower units, and $1.2 billion worth of work is guided by a 20-plus year master plan. Rehabilitations and repairs have been completed on all three units at Center Hill Dam in Lancaster, Tennessee, and unit four at Old Hickory Dam, in Hendersonville, Tennessee.
Connor said his visit to the Nashville District was long overdue. He thanked the teams at all three projects for hosting him and providing information he needs to advocate and make budgetary decisions related to projects across the Corps of Engineers.
“It was highly educational and impressive,” Connor said. “What I loved most was the range of very experienced engineers who have obviously been with us for 20-plus years, and then the new crop of young project managers and engineers doing the work. We see that talent coming up – that’s the best thing to see. The folks that are being trained are going to put us in a good position moving forward decades from now.”
