Arrival Of Giant Beams Marks ‘Huge Step Forward’ For Chickamauga
After more than a decade in storage, 12 massive beams for the Chickamauga Lock Replacement Project are being barged to the site.
The Nashville Engineer District began moving the first of the 12 upstream approach wall beams from the Watts Bar Dam in Spring Hill, Tenn., to the worksite in Chattanooga on August 29. Each trip takes about seven hours.
“These beams are a critical component of the upstream approach wall contract, and getting them to the site is a huge step forward,” said Bob Winters, project manager “We are working with our partners to deliver the wall beams safely.”
Contractor CJ Mahan subcontracted Barnhart Crane and Rigging to move the beams using a hydraulic power system. Three barges are rotating deliveries, transporting one or two beams daily over the next two or three weeks.
Each beam is 10 feet high, 10 feet wide, 120 feet long and weighs roughly 926,000 pounds. The beams were among 42 constructed under a 2010 contract. They were completed in 2013. Twelve were designated for the upstream approach wall. Thirty other beams are for the downstream wall.
Upon delivery, each beam is lifted into place by a large crane and set between bridge supports near the river. Crew members then install steel restrainer bars to connect the beams to the piers.
The nose pier, located on the riverside wall, was lowered to its final configuration August 6 in preparation for the wall beam delivery. It caps off the structure and is designed to help vessels align with the lock entrance. An approach wall also offers mooring space for large tows and is designed to improve both the safety and efficiency of lock operations, according to the Nashville Engineer District.
The project’s upstream approach wall contract is now 68 percent complete. The Nashville District projects the current contract will be completed early next year.
“Watching the transport of the beams is incredibly exciting and a testament to the hard work of both the government and contractor teams in executing this contract as efficiently and safely as possible,” said Cayce Grall, project site manager. “These beams represent an important step toward bringing the lock to full operational capability.”
The new Chickamauga Lock at Tennessee River Mile 471 will be 110 feet wide by 600 feet long and able to process nine jumbo barges in one lockage compared to one barge per lockage in the existing lock, according to the Nashville District. The new lock is being built riverward of the existing 60-foot by 360-foot existing lock and downstream of Chickamauga Dam. A new lock was required because of structural deficiencies of the existing lock due to an alkali reaction in the cement and aggregate that causes concrete growth and threatens the lock’s structural integrity.
Construction on the new lock began in 2004 and continued until 2012, when the work was paused due to funding constraints with the Inland Waterways Trust Fund. Work resumed in 2015. As with all of the locks on the Tennessee River, the existing lock and the one under construction are both owned by the Tennessee Valley Authority (TVA) but operated and maintained by the Corps of Engineers.
Featured image caption: Barnhart crew members use a hydraulic power system to lift a prefabricated wall beam onto a barge for delivery to the Chickamauga Lock Replacement Project’s upstream approach wall contract near Watts Bar Dam. (Photo by Noe Gonzalez/USACE)
