TULSA - Newt-Graham Lock and Dam 18 on the McClellan-Kerr Arkansas River Navigation System has returned to full operation following a number of repairs to the down-stream gates.
For several months, the Corps monitored leaks through the downstream miter gates. It was decided to schedule a dewatering of the lock chamber to discover the cause. With the gates exposed, several areas of damage were uncovered.
According to Johnny Bell, Tulsa District Technical Support Branch Chief for the U.S. Army Corps of Engineers, “When the lock was dewatered, a number of additional repairs showed up that needed fixing to avoid future unscheduled shut downs.” The extra repairs delayed the reopening the lock by two days.
One suspected problem was confirmed, the rubber seal on the bottom of the miter gate was damaged. The bottom seal and backing plate were badly deformed and in some spots torn loose. Drift and debris had jammed against the concrete sill and the seals backing plate causing large gaps between the girder and the chamber base.
Rodney Beard, Tulsa District Navigation Project Manager said, “You never fully know the extent of damage or repairs that are needed until the chamber is emptied. That is why we plan for scenarios A thru Z and ensure our team is prepared for anything. “
Early during the dewater an unscheduled repair was discovered. Debris had damaged a portion of the steel girder in a high stress area of the miter gate. Repair required cutting out the damaged section and welding in a new piece. Prior to repair, the 185 ton gate was supported with hydraulic jacks. Scheduled repairs had to be postponed while the gate was immobilized. Once the gate was repaired, it had to be carefully realigned for smooth operation.
When it became necessary to delay reopening the lock, Steve Taylor, President of Johnston Port 33, told Corps Operations Manager Kenneth Todd, “We fully understand your dilemma. We all have had projects that did not go like we had them on paper. You and your team don’t panic, we know the Corps is doing the best they can to work out those unforeseen problems.”
Col. Richard Pratt, Commander, Tulsa District, U.S. Army Corps of Engineers said, “With the damages discovered during the dewatering, the time required to complete the additional repair work was time well spent to help assure future uninterrupted operations of an important part of our nation’s infrastructure.“
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