en.Wedoany.com Reported - A critical milestone has been achieved at the Chickamauga Lock Replacement Project at mile 471 of the Tennessee River in Chattanooga, Tennessee, as construction crews successfully lifted the first concrete beams for the upstream guide wall in June, each weighing 420 tons.
C.J. Mahan Construction Company LLC, headquartered in Urbancrest, Ohio, which is responsible for the upstream guide wall construction, partnered with McKinney Salvage LLC, based in Baton Rouge, Louisiana, to complete the lifting using a twin-mast barge crane system. Each beam measures 120 feet in length and has a 10-foot square cross-section. The project is overseen by the U.S. Army Corps of Engineers’ Nashville District. Project Manager Cayce Grall stated that the entire lifting process was extremely precise, requiring accurate measurements from the intermediate pier construction phase to ensure each beam is perfectly aligned.
These guide wall beams were manufactured by C.J. Mahan in 2010. During the multi-year storage period, Corps officials conducted material testing and structural integrity inspections.
The upstream and downstream guide walls of the new Chickamauga Lock will use a total of 42 beams. These beams will be stacked between four intermediate piers and two nose piers. After stacking, crews use precision measuring tools, secure the beams with cables, and have a dive team monitor positioning underwater. Grall emphasized that the dive team's role is crucial, as they need to inspect the beam gaps in the water to ensure correct placement, with perfect alignment being non-negotiable.
Nashville District officials expect the upstream guide wall work to be completed by early August. Grall stated: "We are seeing years of planning come to fruition right before our eyes. Our focus remains on safe execution and maintaining momentum. Every lift requires precise coordination, and this team has delivered."
The Chickamauga Lock Replacement Project comprises three contracts, with two currently in execution: the upstream guide wall contract, and the downstream guide wall and old lock decommissioning contract, with C.J. Mahan serving as the prime contractor for both. The Nashville District awarded the downstream guide wall and decommissioning contract to C.J. Mahan in February.
As of mid-February, construction of the new lock was approximately 76% complete. However, on May 8, the Nashville District announced the termination of the lock contract with Shimmick Construction Company, stating that this decisive action was necessary to get the project back on track and protect taxpayer money. Shimmick subsequently announced its intention to appeal the decision.
Cost overruns and schedule delays have long plagued the Chickamauga project and other infrastructure projects of the Corps nationwide. The project was approved in 2003 with an initial cost slightly over $267 million; a 2018 cost estimate was adjusted to over $757 million; as of fiscal year 2026, the cost estimate has risen to $1.566 billion.
The Nashville District reiterated that the goal is to have the new lock operational by 2028. Once completed, the new 600-foot lock will accommodate a full tow of nine barges, compared to the existing lock which can only handle one barge at a time, saving commercial operators and recreational boaters significant time and costs.
