By Sara GoodeyonSeptember 11, 2012
CHOUTEAU, Okla. -- Work involving the repair of a major component of a lock along the McClellan-Kerr Arkansas River Navigation System was recently completed ahead of schedule by the Tulsa District U.S. Army Corps of Engineers.
The work involved the removal and replacement of a pintal ball at Lock 17 at Chouteau, Okla., This was the first time such a repair has been performed to a lock on the MKARNS. The entire lock was emptied of water, an operation referred to as "dewatering," so that the dam gate could be lifted for the removal of the pintal.
Impact to commercial operations along the navigation system was kept to a minimum through extensive planning, spanning several months, in an effort to close the lock for three weeks or less. The lock closed August 27 and reopened to river traffic Sep. 6, with crews scheduled to continue any other required work between traffic.
"The completion of the repair work and the reopening of Lock 17 to river traffic ahead of the scheduled three-week closure was an absolutely amazing effort by an incredible crew," said Col. Michael Teague, commander, Tulsa District USACE.
The need for the repair was discovered during a routine dewatering of Lock 17 in 2009. Since such work had never been done in the district, engineers had no plans or drawings to follow. Tulsa District crews used a process known as "reverse engineering" to develop five different scenarios and contingencies for the removal of the damaged pintal.
Obtaining replacement parts also proved to be a challenge. There were no existing replacement parts available "off the shelf," thus requiring the team to design the parts and have them built to order. This raised the possibility that the custom parts might not be an exact fit, something the team might have to learn the hard way during the scheduled three-week dewatering. As evidenced by the early completion of the work, the pintal did fit, and it proved to be a success in civil engineering and planning for the Tulsa District team.
"Crews finished all below-water level work late Wednesday evening, Sept. 5. We pulled all pumps, bulkheads, and stop logs, and watered the chamber back up Thursday, Sept. 6," said Kenneth Todd, MKARNS navigation operations manager.
Lessons learned from this repair project will be put to use for other repairs to locks along the MKARNS; it is an aging system, and all locks in the system have symptoms of wear and tear, such as the grinding and vibrations created by metal-against-metal when the gates are opened and closed.
The MKARNS is a 440-mile waterway that links Oklahoma and the surrounding five-state area with ports along the nation's 25,000 mile inland waterway system all the way to New Orleans and the Gulf Intracoastal Waterway. About 13 million tons of cargo is transported annually along the system.