Commercial tows traveling to and from a 20‑state region rely on the Kentucky Lock on the Tennessee River and the Barkley Lock on the Cumberland River – two critical gateways connecting more than 700 miles of navigable waterways. Because navigation downstream of Barkley Lock is challenging, more than 80% of commercial tows use the Kentucky Lock, often exceeding the 600‑foot capacity of the existing structure. This required time‑consuming double lockages that created four‑ to seven‑hour delays, among the longest in the inland waterway system. The Kentucky Lock Expansion Project addressed this bottleneck by constructing a new 1,200‑foot lock to improve efficiency and freight capacity across the region.
What challenges did STV address?
The project required a deep understanding of complex geologic conditions, fluctuating water levels and constant barge traffic. STV had to support a major lock expansion while drilling from land‑based platforms, floating barges and an aerial platform mounted to the existing guide wall. Karst voids in the limestone bedrock added further complexity, demanding thorough subsurface evaluation and mitigation to support a stable foundation design.
What solutions did STV deliver?
STV performed a comprehensive geotechnical investigation consisting of 19 borings using HWT‑sized casing and HWL coring equipment across three drilling phases. Working closely with Johnson Brothers Construction, the team designed and installed stabilizing collars on the lock’s vertical guide wall to secure casing for rock coring. STV executed Standard Penetration Tests, pressure testing for water inflow and pressure grouting of each completed borehole in coordination with USACE Nashville District geologists.
How does this project benefit the region and community?
The new 1,200-foot lock dramatically reduces wait times for commercial tows, improving the reliability and efficiency of freight movement throughout the Tennessee River Basin. By mitigating delays, the project strengthens regional commerce, supports industries that rely on inland waterways and enhances the overall resilience of the national freight network.
Key stats and accolades
- 110′ x 1,200′ lock dimensions
- 80% of regional commercial tows depend on Kentucky Lock
- 19 geotechnical borings across land, floating and aerial platforms
- Karst void identification and mitigation through SPT, pressure testing and grouting
