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Downstream Monoliths

Grand Rivers, KY.


U.S. Army Corp. of Engineers


$380 m


Under construction

About the Project:

Downstream Monoliths is the name of the current construction phase of the Kentucky Lock project, which is a multi-phase project located in Grand Rivers, Kentucky, at Mile 22.4 of the Tennessee River.  The project represents work awarded by the United States Army Corps of Engineers (USACE) to construct the remaining portion of the new 110’ x 1200’ navigational lock structure, which is being built on the landward side of the existing lock (which is 110’ x 600’ in size). The first phase of this project was known as Upstream Monoliths and was awarded to Thalle Construction Company and was completed on May 29, 2017. Thalle is proud to have been selected to complete this structure in strong partnership with the USACE.  Click here to read more about the Upstream Monoliths project by Thalle Construction Company.

The original lock and dam were completed in the 1940’s, the new contract represents a major investment in the country’s infrastructure to improve navigation on the Tennessee River.  Our current project will be twice the length of the existing 600’ lock and when complete, the new lock will provide significant improvements in the efficiency of river transportation of essential commodities and raw materials by reducing wait times and increasing shipping capacity.  According to the USACE, this is the 3rd highest priority lock project in the United States.  


Thalle’s scope of work consists of developing all onsite infrastructure to support the project including off-site electric substation upgrades, installation of power line upgrades, five tower cranes, an onsite concrete plant capable of producing the 375,000 cubic yards of concrete required for the structure, thousands of feet of conveyors to transport the concrete from the plant to point of placement, formwork and steel fabrication shops, laydown yards and aggregate stockpile structures.  Construction of the structure will include assembling forms, reinforcing steel, embedded metal components and placing concrete in 5’ vertical lifts for each of the 52 monolith sections of the structure which span over 100 vertical feet from foundation to top out. 


Ultimately, Thalle will place over 1,000 concrete lifts to complete the remaining monoliths over the span of 5 years.  Thalle will provide full management of the project including safety and quality control aspects of executing this project and is proud to partner with the local carpenter and labor unions to assemble a construction workforce of well over 300 full-time teammates necessary to deliver this project on schedule.


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