Crews working on the US Army Corps of Engineers’ $1.56 billion Kentucky Lock Addition to the Tennessee River reached a milestone with the recent completion of the first downstream monolith.
The project will add a 1,200-foot-long, 110-foot-wide lock chamber to alleviate heavy traffic delays that are occurring with the existing 600-by-110-foot lock. The Kentucky Dam lock is the lowest on the Tennessee River, located at mile marker 22.4 in Grand Rivers, Kentucky, near where the Tennessee meets the Ohio River.
The first completed monolith, named L31, is at the lowest elevation of 50 monoliths to be built under the Corps’ contract with Thalle Construction Co. So far, 35 are under construction. Each is being built with sequential 5-foot concrete lifts, and L31 required 17 lifts.
US Army Corps of Engineers Chart Nashville District“We still have many monoliths to complete, but this first top-out is an important milestone that gives us confidence moving forward,” Capt. Rachel Nelson, Kentucky Lock Addition project manager, said in a statement.
The Corps awarded a $167 million base contract to Thalle for the work through 2021 and subsequently exercised eight contract options that brought the price to $380 million. Construction began in 2022. The downstream monoliths are scheduled to be completed in May 2027 and the entire project is expected to be completed in 2029.
Earlier this year, Thalle and the Corps celebrated 1 million work hours worked without a lost time accident, according to the Corps.
Work on the Kentucky Lock Addition began 25 years ago, in 1998, but funding issues slowed work over the years. Prior to this current contract, crews from various companies completed some of the work, including the relocation of four transmission towers, the construction of relocated downstream road and rail bridges, the construction of the upstream monoliths, and other work. Thalle also built the monoliths upstream.
