OLD HICKORY, Tenn. (July 27, 2015) – Old Hickory Lock holds 19 million gallons of water when fully operational; however, the U.S. Army Corps of Engineers Nashville District recently closed it to navigation and drained it for scheduled repairs.
Charlie Bryan, Navigation Facilities Supervisor at Old Hickory Lock and Dam, said the Nashville District closes the lock every five years, pumps the water out, inspects underwater components, and makes repairs to the gates, valves and bushings as required.
“This time we’re concentrating on the lower miter gates, correcting problems in the contact blocks… a lot of cracked welds had to be re-welded… and we also had ERDC (Engineer Research and Development Center) come in and apply a carbon fiber reinforced polymer to the lower gates,” Bryan said.
The team from ERDC applied CFRP patches shortly after the lock was dewatered July 14. They plan to monitor the repair of fatigue cracks, which is expected to extend the fatigue life of the steel structures, said Guillermo Riveros, research civil engineer with the ERDC Computational Analysis Branch.
Riveros said the team from ERDC that worked at Old Hickory Lock consisted of himself and Matthew Nelms, University of Mississippi; Anthony Perez, University of Puerto Rico; and Bashir Ahmadi, Colorado State University.
The applications of CFRP at Old Hickory Lock will be evaluated to determine the effectiveness of this repair method and how it is impacted by exposure in a wet environment, Riveros said.
The Nashville District began constructing Old Hickory Lock in 1954, opened it to navigation in 1957, and to this day the lock operates with its original components. The longevity of the lock’s equipment can be attributed to the hard work and dedication of maintenance crews over the span of more than seven decades, Bryan added.
Bruce Johnson, lock and dam equipment mechanic supervisor, said teams are now working around the clock to fix cracks in the gates, to repair the struts that open and close the gates, and inspect areas in the culverts where water enters the lock chamber.
“Every five years we look at the pins and bushings on the valves and the overall condition of the valves to see if repair is needed,” Johnson said.
Mechanics are required to comb over the entire lock when it is dewatered and pinpoint any components that are worn or in disrepair.
Danny Tanner, lock and dam equipment mechanic at the Cumberland River Operations Center, is inspecting the steel gates and making welding repairs. He said the gates are huge steel structures that deteriorate from constant exposure to water, and it takes time to make assessments and then to make repairs to ensure they continue to operate properly for years to come.
“That’s why it’s a challenge to work on this metal, because it does stay under water so much, so you have to do a lot of pre-work in order to do the welds,” Tanner said.
The lock is located at river mile 216.2 on the Cumberland River. A total of 3,940.698 kilotons of commerce navigated through Old Hickory Lock and 1,112 recreational vessels locked through in 2014.
Old Hickory Lock is scheduled to reopen Aug. 4, 2015. Vessels cannot lock through during the closure. Call the Nashville District Navigation Branch at 615-736-5607 for more information.
(The public can obtain news, updates and information from the U.S. Army Corps of Engineers Nashville District on the district’s website at www.lrn.usace.army.mil, on Facebook at http://www.facebook.com/nashvillecorps and on Twitter at http://www.twitter.com/nashvillecorps.)