Miter Sill Concrete Failure Forces Demopolis Lock Closure

The Mobile Engineer District has announced an emergency closure of Demopolis Lock, located near Demopolis, Ala., just below where the Black Warrior River enters the Tombigbee River, following a concrete failure at the lock’s upper miter gate sill. The closure, announced January 16, cuts off both the Tennessee-Tombigbee Waterway and the Black Warrior-Tombigbee Waterway (BWT) from the Port of Mobile and the Gulf Intracoastal Waterway.

Mobile District officials said the concrete failure did not involve an allision or other vessel-related incident. Rather, the lock operator “heard a big boom,” then saw water rushing under the east-side upper miter gate leaf.

As of January 18, Corps officials said they planned to attempt closing the lower miter gate that night, with the assistance of a pair of Parker Towing Company vessels. Mobile District Chief of Operations Nelson Sanchez said a Tennessee Valley Authority towboat was en route with a floating plant, with plans to set the lock’s upper stop logs Saturday, January 20. With the upper stop logs in place, the Corps will be able to safely raise and lower the water level in the lock chamber again.

After that, the lock’s lower stop logs will have to be set. Unfortunately, with the BWT’s towboat, the mv. Lawson, currently on drydock, Sanchez was unsure when the Corps would be able to dewater the lock.

“We’re still looking at late next week to have it dewatered,” Sanchez said.

Only then will the Corps move into phase two: inspection and assessment. An understanding of what happened at the lock and how to address it will follow.

Sanchez said his best guess would be for a 30- to 60-day closure.

“Once we dewater and see the extent of the repairs needed, that’s when we’ll have a handle on it,” he said.

Wynne Fuller, president of the Warrior-Tombigbee Waterway Association and a former chief of operations for the Mobile District, said he’s confident the district will be able to execute a repair plan once the extent of the damage is known.

“The Corps has done a lot of research and development work on these types of repairs in the past,” he said.

In the meantime, Fuller said he’s proud of the way industry and the Corps are communicating and collaborating during the closure, with Parker Towing and Cooper both already assisting at the lock.

“The support from industry has been tremendous,” he said.

The impact on industry also stands to be tremendous, Fuller said. Coal remains a major cargo on the BWT, with coal mined at the upper end of the Black Warrior River exported through the Port of Mobile’s McDuffie Coal Terminal. Coal can be shifted to rail for the short term, Fuller said.

“But you could potentially lose capacity for a full ship’s cargo per week at McDuffie, so that’s concerning,” Fuller said.

The closure poses a similar challenge for the Tenn-Tom.

“Obviously this closure is going to have a significant impact on business and industry in Mississippi, Tennessee and Kentucky, and beyond,” said Mitch Mays, administrator of the Tennessee-Tombigbee Waterway Development Authority and president of the Tennessee-Tombigbee Waterway Development Council. “This is going to be a disruption for a lot of companies.”

The difference between the BWT and the Tenn-Tom is that, on the Tenn-Tom, operators and cargo owners have the option of going north to the Tennessee and Ohio rivers, then down the Mississippi River to the Gulf.

“But if you go north, there’s still added costs because it’s a much longer distance,” Mays said.

Both Mays and Fuller said the unplanned closure at Demopolis demonstrates the importance of robust funding to maintain and improve the nation’s waterways, with many locks and dams in the United States well beyond their life span. Currently, the Corps is conducting a waterway improvement study for the Tenn-Tom and the BWT, with deepening and boosting resiliency on the two waterways at the forefront.

“This lock is about 70 years old,” Fuller said. “This closure is making me think really really hard about the need to study both Demopolis and Coffeeville.”

Caption for photo (click on photo for full image): Water pours into Demopolis Lock after an apparent concrete failure in a miter gate sill.