Using in-house crews, Tulsa District replaced the pintle balls and bushings on the upstream miter gates at W.D. Mayo Lock and Dam 14, over the period August 31 – September 12, and performed other needed repairs, completing the work three days ahead of schedule.
This huge undertaking, outside the normal maintenance work done along the McClellan-Kerr Arkansas River Navigation System (MKARNS), took two years to plan. It required procuring and getting in place the necessary equipment, parts and supplies, and then executing the work in a three-week window during which the lock was dewatered.
After close to 45 years in operation the bushings and the pintle ball, essentially the hinge that the gate swings on, were in danger of wearing out. Before the replacement, the gate was sitting flat on the pintle ball preventing grease needed to lubricate the cross-area from getting to the pintle ball.
Over time, if the needed repair can’t be done, the bushing wears down, in turn causing the gates to drop, damaging the upper linkage and forcing the gates out of alignment. Should the bushing wear down to the gate or the concrete, it could result in an unscheduled long-term shutdown. Such a closure would have a detrimental impact to the shipping industry and to local economies.
During the dewatering, repair crews used specialized equipment needed to raise the 375,000-pound miter gates 18 inches using two 200-ton jacks. They then crawled under the massive miter gates to remove and replace the pintle ball and bushings. They lined up the gates and set them back into place, flooded the chamber, and returned Lock 14 to operation.
While the lock chamber dewatered, crews performed as much maintenance to other areas of the lock as possible within the execution window. Crews did inspections on the lower miter gates, spot painted, and sandblasted and repaired corroded areas on the miter and quoin areas of the gates.
The District undertook the entire effort using in-house marine fleet personnel, as well as several support personnel from across the District.
This is the second time Tulsa District replaced pintle balls at an MKARNS Lock and Dam. The first occurred two years ago at Lock and Dam 18.
The District coordinated with stakeholders so that the work occurred at the least disruptive time for ports and shipping interests who rely on the MKARNS to do business.