Wilson Lock Repairs Remain ‘On Schedule’
Crews are on schedule to resume work later this month inside the main chamber at Wilson Lock and Dam while design work and machining of replacement components continues.
In a weekly industry update call February 11, Brian Mangrum, chief of the Nashville Engineer District’s technical support branch, said during the previous week the Corps of Engineers met with the Tennessee Valley Authority’s Power Services shop, which is forging the pintle components for the gate assemblies. Machining is still underway, he said, adding that progress has been good and that fabrication remains a top priority.
All components needed to stabilize the gates have also been received, according to Nikki Berger, TVA’s navigation program supervisor.
However, work on fabrication of gate bracing has been paused “as our design team finalizes the agency technical review process on that,” Mangrum said. He said he didn’t expect that pause to be extended.
“We’ll be on schedule when we get the green light to resume,” Berger said.
Mangrum said he did not expect the “brief pause” to impact the plan to begin repairs once the heavy capacity fleet is mobilized February 24.
“Everything is still on schedule with that planned mobilization and initiating the lower chamber closure to begin dewatering in just a little over a week from now,” he said.
The projected completion date remains June 14.
The main chamber at Wilson, Tennessee River Mile 259.4, in Florence, Ala., has been closed since September 25, after lock operators heard “popping” noises that turned out to be the gates cracking in multiple places. The pintle assemblies, which act like hinges to swing the lock gates open and closed, must be replaced due to the cracking.
Engineers believe an issue with quoin gaps was causing the pressure of water against the lock as it filled and emptied to be on only the gate and not the entire chamber, as designed.
The main chamber has remained closed since September, but traffic continues to move in the much smaller, two-step auxiliary chamber, which can hold only one standard-sized barge at a time. The Corps of Engineers’ lock queue report showed 36 tows in queue the afternoon of February 11 with five tows waiting to transit since January 28.
One new item announced to those on the call is that the Corps of Engineers wants to offer an on-site visit at Wilson to interested industry members. A date has not been finalized, but the timeframe will likely be in middle or late March, Mangrum said.
As he does every week, Mangrum went through critical path activities that must be completed as part of the repairs. They include setting the caisson on the lower end to dewater the chamber, installing gate supports, jacking each gate concurrently to access the pintle assemblies, replacing pintle assembles, performing specific weld repairs to include stabilization on each gate and repairing quoin gaps as needed.
