USACE Announces Plans for Wilson Lock Main Chamber Repair

Ty Melton, a lock mechanic with the U.S. Army Corps of Engineers Nashville District, dons diving headgear with the help of Matt Williamson, a fellow mechanic at Wilson Lock in Florence, Ala., Oct. 9, 2024. Dive-certified mechanics like Melton and Williamson are crucial to getting a firsthand look at any underwater maintenance concerns, such as the cracks in the land and river sides of the gates at Wilson that have caused the closure of the main chamber. USACE PHOTO BY JEREMY CROFT

The U.S. Army Corps of Engineers Nashville District and the Tennessee Valley Authority have released a timeline for planned repairs to the main chamber at Wilson Lock, which has been closed since Sep. 25, 2024.

The current projected date for reopening the main chamber is spring 2025. This timeline is subject to change dependent on many factors, including weather and the availability of materials and staff.

“We understand that the closure of the main chamber has a significant impact on the navigation industry that operates on the Tennessee River,” said Lt. Col. Robert Green, USACE Nashville District commander. “Returning the main chamber of Wilson lock to operation as soon as possible is a priority for USACE and the Nashville District in particular.”

Ty Melton, a lock mechanic with the U.S. Army Corps of Engineers Nashville District, swims toward the land side gate of the main chamber at Wilson Lock in Florence, Ala., Oct. 9, 2024. Melton, like other lock mechanics, is dive-certified and can provide an up-close look at any underwater maintenance issues to facilitate repairs. USACE PHOTO BY JEREMY CROFT

Green added, “we are conducting temporary repairs over the next month and once complete, we will be coordinating with our partners at TVA to evaluate risks associated with returning the main chamber to limited operations while parts are fabricated for a more permanent repair.”

With a maximum lift of 100 feet, the main chamber at Wilson Lock is the highest single-lift lock east of the Rocky Mountains. An auxiliary chamber has two 60-by-300-foot chambers that operate in tandem. The auxiliary chamber is currently open, although its smaller size and longer lock times have led to shipping delays. The lock and dam provides flood mitigation, hydropower generation and navigation control for the community of Florence, northern Alabama in general, and the inland shipping industry.

A dive support team with the U.S. Army Corps of Engineers Nashville District monitors data from lock mechanic Ty Melton’s helmet-mounted cameras as he examines the land side gate of the main chamber at Wilson Lock in Florence, Ala., Oct. 9, 2024. The dive support team is responsible for coordinating with the diver to accomplish maintenance missions and for the diver’s safety and welfare, providing air, drinking water, and communications capability through the coiled cables pictured behind the team. USACE PHOTO BY JEREMY CROFT

The USACE Engineer Research and Development Center (ERDC) in Vicksburg, Miss. assigned a Remotely-Operated Vehicle team to assist the Nashville District in obtaining underwater photos and video footage of the cracks in the lock gates. The Great Lakes and Ohio River Division has also tasked vessels from the Rivers Regional Repair Fleet to position at Wilson Lock to assist with moving heavy equipment and gate components during repair operations.

Key milestones in the repair timeline include:
  • Repairs to the river caisson slot, completed at the end of last week.
  • USACE-TVA risk assessment, scheduled to be completed in early December.
  • First dewatering of the main chamber lower end to inspect and conduct initial repairs to assess the risk of returning to limited operation, scheduled from early November to late December 2024.
  • Determining the root cause of the pintle cracking, scheduled to be completed by the end of 2024.
  • Second dewatering to replace pintle assemblies and complete repair and stabilization of the gates, scheduled for the first three months of 2025.
  • Completion of repairs to the pintle and gates, scheduled to be completed in spring 2025.

“Our goal is to complete this repair as soon as possible while doing our utmost to ensure the safety of our crews,” said Megan Simpson, Maintenance section chief with the Nashville District. “Wilson Lock is a vital component of a navigation system that helps provide economic and hydrological stability to the Tennessee River Basin.”

An aerial view of the ND-40, a maintenance barge belonging to the U.S. Army Corps of Engineers Nashville District, from the top of the main chamber at Wilson Lock in Florence, Ala., Oct. 9, 2024. The barge serves as a base of operations for dive-certified district lock mechanics as well as operators of a Remotely-Operated Vehicle (ROV) visiting from the USACE Engineer Research and Development Center (ERDC). The power cable connecting the ROV to the barge is visible in the upper-right corner of the photo. USACE PHOTO BY JEREMY CROFT

The Tennessee Valley Authority owns the locks and dams along the Tennessee River and the U.S. Army Corps of Engineers operates and maintains the locks for navigation, in partnership with TVA.

The Nashville District has a longstanding partnership with the Tennessee Valley Authority to operate and maintain navigation facilities on the Tennessee River. More than 11.4M tons of goods make their way to and from the Ohio River every year through USACE-managed locks on the Tennessee River.