Concrete results expected this summer for replacement lock project at Chickamauga Dam

A commercial airliner, to left, is on final approach to the Chattanooga Metropolitan Airport Tuesday as two construction work walk across a recently installed walkway above the Chickamauga Lock construction site where five cranes have been moved in to be used in the building of the new waterway gate at Chickamauga Dam.

Contractors working at the Chickamauga Lock are installing three tower cranes this summer to help deliver concrete and other equipment to build a new and bigger replacement lock on the Tennessee River.

Adam Walker, the project manager for the Army Corps of Engineers project at the Chickamauga Dam, said an 1,100-foot-long conveyor system will be installed to bring the concrete made in the batch plant set up on the north side of the river to the lock chamber in the river. The cement will form the 50-foot wide concrete walls at the base of the new lock.

"We hope to have some of the concrete placements for the new lock by July or August," Walker said.

"The options we have in place now with our available funding will take us to December of 2020. All total, we hope to have all of the concrete work and walls in place by May 2023, if we get the available funding to exercise all of our options."

photo A car carrier passes atop the Wilkes T. Thrasher Bridge midday Tuesday, two men work high above the site at Chickamauga Lock securing a crane tower to be used in the construction of the new water gateway at Chickamauga Dam.

Three giant cranes, including two being put in place in or near the new lock being built below the dam in the river, are being erected by AECOM Construction Services, the contractor hired to build the new 600-foot-by-110-foot lock chamber.

The work is part of the biggest construction phase yet in the estimated $757.7 million project to replace the crumbling existing lock, which was built in 1940, with a new and bigger lock through the dam.

In the current fiscal year, the Corps has allocated $89.7 million for the Chickamauga project - the biggest funding year since the Corps began work on the new Chickamauga Lock more than a decade and a half ago.

In his budget proposal for fiscal 2020, President Trump did not include enough money in the Corps of Engineers civil works budget to fund continued work on the new locks being built on the Tennessee River at both the Chickamauga and Kentucky dams. But Congress has traditionally restored federal funding for the Inland Waterways Trust Fund, which pays for such replacement locks.

The existing lock, which is only 60-foot-by-360-foot in size, suffers from "concrete growth" from the rock aggregate mixing with the river water.

The concrete for the new lock has been tested to avoid such problems. Because of its bigger size, the new lock will be able to handle nine standard-size barges at one time, allowing for easier and faster shipment on the river to connect with the 318 miles of navigable waterways upstream of Chattanooga.

Walker said the new lock will require 285,000 cubic yards of concrete, or the equivalent of 35,600 standard cement truck hauls. That concrete would be enough to fill three and a half balls the size of the Epcot Spaceship Earth geosphere, Walker said.

Lt. Col. Cullen Jones, commander of the Nashville district of the Army Corps of Engineers, said heavy winter rains delayed work on the new lock earlier this year. But with adequate funding, the new Chickamauga lock could be finished by 2024, Jones said.

Contact Dave Flessner at or at 757-6340.