Dredging/Infrastructure Report: Lock and Dam 25 Continues On Schedule

The U.S. Army Corps of Engineers’ Lock and Dam 25 1,200-foot lock project remains on schedule, with several major milestones reached in recent months as construction activity continues at the site.

Bryan Dirks, technical lead for the project, said the Corps completed the project’s design in June 2026. The completed design included more than 2,000 drawings that were issued with the request for proposals for the project’s largest construction contract.

“It’s a big deal because that completes the design for the entire scope of the project,” Dirks said, describing the completion of design as a significant milestone for the large, complex project.

The design was led by the Corps’ Inland Navigation Design Center Mandatory Center of Expertise, allowing the project team to draw on expertise from across the Corps.

The Corps also awarded its latest advanced contract in June and issued the request for proposals for the main lock construction contract in July.

The advanced contracts are smaller projects being completed ahead of the main lock construction contract. Dirks said the contracts are intended to reduce the main contract’s schedule and address long-lead items ahead of the primary construction effort.

One of those contracts involves fabrication of 21 lock bulkheads. The bulkheads are being fabricated by G&G Steel in Alabama, with 17 of the 21 completed. Delivery is expected in January.

The bulkheads will be used to dewater the lock chamber once the lock wall monoliths are completed, allowing the work to proceed without making the bulkheads part of the critical path for the main lock construction.

Guide Cell

Another advanced contract is for the downstream guide cell, which recently completed its foundation work and is being constructed by Massman Construction. The foundation consists of 10 drilled shafts, with the 10th recently completed. The contractor is now removing the drill rig before beginning sheet-pile installation, followed by placement of mass concrete.

The guide cell is expected to be completed in January. Dirks said the structure will provide an important navigation aid for commercial traffic during and after construction of the new lock.

As the new lock chamber is constructed, the downstream guide cell will provide commercial vessels with a structure to land on and get aligned as they enter the existing 600-foot chamber.

The need for the guide cell was identified during the design process following a ship simulator study at the Corps’ Engineering Research and Development Center (ERDC) in Vicksburg, Miss., in which commercial navigation pilots participated.

Another advanced contract, Phase 2C, involves construction and operation support facilities. The work includes maintenance and storage buildings that will provide space for Corps operators and maintainers to keep the existing 600-foot lock operational during construction of the new lock.

Dirks said the foundation and slab for the storage building have been completed, with structural steel being erected and roof work next. Work also is continuing on the maintenance building.

The most recently awarded advanced contract, the Foundation and Site Preparation contract, was awarded to J.F. Brennan Company and Brennan has begun mobilizing at the site.

One of the first tasks will be dredging additional staging space for the main lock contractor. The site is relatively congested, Dirks said, making additional staging space important as construction of the new lock gets underway.

The contract also includes work to reestablish the new lock foundation with dredge fill and a sheet-pile combination wall to reestablish the lock foundation. Dirks said that work is expected to reduce the amount of time needed to complete the main lock contract.

With three contractors currently working on the advanced contracts on site, managing the interfaces between contracts has been one of the challenges at the site. Dirks said the Corps’ on-site staff has been working with contractors to coordinate work in the limited space.

“There’s always unexpected challenges” with construction, particularly when foundation or underground work is involved, Dirks said. He added that the project team has been working to identify and mitigate potential risks before they become problems.

So far, none of the unexpected challenges have delayed the project, Dirks said.

The advanced contracts, along with a previously completed Phase 1 contract involving modifications to the existing intermediate wall, represent about $100 million in completed or ongoing construction, he said.

“It’s starting to get really exciting out there,” Dirks said, noting that construction activity is beginning to bring the plans and drawings into reality.

Safety, Efficiency

Once completed, the new 1,200-foot lock chamber is expected to improve safety, redundancy and efficiency for commercial navigation.

The existing 600-foot chamber requires many modern tows to be broken apart so that the barges can pass through in multiple lockages. Dirks said eliminating that process with a 1,200-foot chamber will improve safety for deckhands who currently have to separate and reconnect barges.

The project also will provide redundancy. Currently, if the 600-foot chamber is unavailable because of planned or unexpected maintenance, commercial traffic has no alternate lock chamber at the site. Once the new chamber is completed, the existing 600-foot chamber will serve as a backup.

The larger chamber also will improve efficiency by allowing commercial tows to move through the lock without being broken apart.

Dirks said coordination with commercial navigation and other users has been a priority throughout the project. The Corps has sought input from end users through meetings and other engagement efforts, with the goal of minimizing impacts to navigation and making those impacts as predictable as possible.

As construction progresses, the Corps plans to continue working with users to improve the predictability of project-related impacts.

“This is a really cool project that’s important, not only for those that use the river system, like commercial navigation on the inland navigation system, but for the nation as well,” Dirks said.

Featured photo caption: Workers continue construction activities as part of the Lock and Dam 25 1,200-foot lock project. (Photos by Jeremy Idleman/Corps Public Affairs Specialist)