Tows waiting to pass Kentucky Lock lose an average of nine hours. That is the worst delay anywhere in the U.S. inland waterway system, and it happens because a 600-foot chamber has to break a modern 15-barge tow into two lockages and reassemble it on the far side. The Kentucky Lock Addition puts a 110-by-1,200-foot chamber on the landward side of the existing structure so a full tow passes in one cut.
Project Scope
The new chamber is built from 64 structural monoliths, poured in lifts inside a dewatered cofferdam beside a dam that stays in service throughout. Thalle Construction Co. holds the downstream monolith package, awarded in September 2021 at a $167 million base and taken to roughly $380 million in March 2022 when the Corps exercised eight options across a 67-month period of performance. Southland Holdings and Johnson Bros. built the downstream cofferdam. The Tully Group has handled marine and civil work, and STV Inc. did design engineering. Three relocations are already finished: two miles of US 62, two miles of the Paducah & Louisville Railway, and four new 161 kV transmission towers. The first downstream monolith, L31, topped out in October 2024 after 17 concrete lifts.
Why It Matters
Kentucky Lock moves about 57 million tons of cargo a year, worth more than $10 billion. Every hour a tow sits in the approach is fuel burned and a barge not delivered, and that cost lands on grain, coal, aggregate and chemical shippers across the Tennessee and Ohio valleys. The project was authorized in WRDA 1996 at $1.45 billion; the Corps’ current certified estimate is $2.74 billion at FY2026 price levels, which requires reauthorization. It was roughly 60% physically complete in mid-2026, and management moved from the Nashville District to the Pittsburgh District in August 2025. Thalle passed 1.5 million work hours on the monolith package without a lost-time incident.
Downstream monolith work runs into 2027. The remaining contracts for approach walls, electrical and mechanical systems, operations buildings and site restoration have not been awarded yet, which is why full completion sits in 2029 rather than sooner.
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Project Team & Details
| Owner / Client | Tennessee Valley Authority |
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| Consultants | STV Inc. (Design Engineering)
U.S. Army Corps of Engineers, Pittsburgh District (Project Management) |
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| General Contractor | Thalle Construction Co. |
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| Major Subcontractors | Southland Holdings / Johnson Bros. Corporation (Downstream Cofferdam) |
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| Status | Under Construction |
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| Delivery Method | Design-Bid-Build |
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| Funding Source | Public (Federal) |
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