Contractors working for the U.S. Army Corps of Engineers Pittsburgh District install a 23-foot-tall concrete shaft enclosure weighing approximately 120,000 pounds as part of the guard wall at the Monongahela River Locks and Dam 4 in Charleroi, Pennsylvania, Nov. 16, 2023.

Featured Stories

Filter Featured Stories

Featured Stories

Kentucky Lock Addition Project reaches first monolith top-out milestone

U.S. Army Corps of Engineers Nashville District
Published Oct. 17, 2024
Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed.

Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed. (USACE Photo by Bodie Richardson)

Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed.

Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed. (USACE Photo by Bodie Richardson)

Graphic showing Kentucky Lock Addition Project located in Grand Rivers, KY. Graphic shows what the project will look like when finished and identifies the L31-17 monolith and lift that represent the first "top-out" of a monolith at the project. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed.

Graphic showing Kentucky Lock Addition Project located in Grand Rivers, KY. Graphic shows what the project will look like when finished and identifies the L31-17 monolith and lift that represent the first "top-out" of a monolith at the project. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed. (Courtesy Graphic)

View of the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed.

View of the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed. (USACE Photo by Bodie Richardson)

Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed.

Construction workers from contractor Thalle Construction complete the first monolith “top-out” on the Kentucky Lock Addition Project located in Grand Rivers, KY, Oct. 12, 2024. A monolith is a single structure of concrete that is in the shape of a column. There are a total of 50 monoliths that are to be constructed made from five-foot layers of concrete. Each five-foot layer is called a lift. Early Saturday morning, the final concrete lift was completed for a monolith located on the downstream side of the lock being constructed. (USACE Photo by Bodie Richardson)

GRAND RIVERS, Ky. – On Oct. 12, 2024, the U.S. Army Corps of Engineers Nashville District, in partnership with contractor Thalle Construction, marked a major milestone in the Kentucky Lock Addition Project with the first monolith top-out of the project’s Downstream Lock Monolith contract. This accomplishment reflects significant progress in constructing the new lock, which aims to enhance navigation efficiency on the Tennessee River.

The milestone was achieved with the final concrete lift placed on monolith L31, located at the downstream end of the lock. From 1:30 a.m. to 7:55 a.m., Thalle Construction crews completed the placement of the last five-foot layer of concrete, known as a lift. A total of 17 lifts were placed to complete this monolith.

“This is a tremendous step forward for the Kentucky Lock Addition Project,” said Army Capt. Rachel Nelson, Kentucky Lock Addition project manager-forward. “The successful top-out of monolith L31 represents the dedication and hard work of our entire team. It’s the first of many milestones that will bring this project closer to completion.”

The Kentucky Lock Addition Project is constructing 50 monoliths during this contract, 35 of which are currently in progress. Each monolith is built from sequential five-foot concrete lifts to create the towering columns that form the core of the lock’s structure. While the first top-out is complete, the team remains focused on finishing the remaining monoliths.

Monolith L31, located on the downstream side of the lock, sits at a lower elevation compared to other monoliths that will eventually surround the lock chamber, which will rest at a higher elevation. The variation in monolith heights reflects the complex engineering required to support the lock’s design and functionality.

“We still have many monoliths to complete, but this first top-out is a major milestone that gives us confidence moving forward,” Nelson added. “Our team will continue to work diligently with the contractor to ensure the Kentucky Lock Addition is constructed safely and to the highest standards.”

The Kentucky Lock Addition Project aims to alleviate delays caused by heavy river traffic along the Tennessee River. Once completed, the new lock chamber will be 1,200 feet long and 110 feet wide, making it capable of accommodating modern tows and large commercial vessels that often experience bottlenecks waiting for the existing 600-foot lock. The expanded capacity will significantly improve the flow of commercial and recreational vessels, reducing wait times and boosting operational efficiency. This improvement is expected to contribute to regional economic growth by streamlining freight movement and enhancing the river's reliability as a transportation corridor.

With 35 monoliths actively under construction and more milestones on the horizon, the U.S. Army Corps of Engineers and Thalle Construction remain committed to advancing the project safely and efficiently.

The public can obtain news, updates and information from the U.S. Army Corps of Engineers Nashville District on the district’s website at https://www.lrd.usace.army.mil/About/Districts/Nashville-District /, on Facebook at www.facebook.com/nashvillecorps and on X at www.twitter.com/nashvillecorps.  

 


Chick Lock

Through deeds, not words, we are BUILDING STRONG®