Cannelton lock dewatered for critical repairs

Published Aug. 17, 2017
Repairs are being done on the Cannelton Locks and Dam, on the Ohio River in Indiana. Before work could begin, the 1,200 foot lock chamber had to be dewatered, which involves pumping the water out giving the crew room to work in the nearly-empty chamber. Bulkheads were put into place to keep water out of the chamber at both ends. The miter gates are being inspected and worn out components on the lower gates will be replaced. The work began in June and is expected to continue through the fall of 2017.

In March 2017, the operators noted that the downstream middle wall gate would not miter – or close – properly against the bottom of the chamber, referred to as the miter sill. Engineers performed an inspection of the gates and discovered that critical components were failing and causing the wall gate to hit the submerged sill, preventing it from closing all the way. 

To do the work on the lower gates, the gate leaves – or swinging doors – will be jacked up by four 200-ton hydraulic rams and specialized guides. The anchor arms, pintle ball and bushing, and contact blocks will be removed and replaced. The 250-ton miter gate leaf rests on a pintle ball which allows it to pivot. The gate is secured to the wall at the top of the structure by a gudgeon pin and anchorage components.

Strut arms allow the gate to swing open and closed. These components are all part of what makes the gates operate at the top and at the bottom where the gate is attached to the guide wall.

“The work will replace critical components of the downstream middle wall gate, and greatly improve the reliability of the chamber so navigation can continue,” said Craig Moulton, chief, maintenance, technical support branch, Louisville District. “If these repairs were not performed, the gudgeon bushing would continue to deteriorate until the chamber could not be operated any longer.”

“At some point in time, it could get so bad that [the Corps] would have to shut the chamber down,” Moulton continued. 

Bob Szemanski, project engineer, U.S. Army Corps of Engineers Pittsburgh, operations and maintenance section, who is in charge of repairs, said the work is challenging.

The medium capacity fleet of the Regional Rivers Repair Fleet, Huntington, West Virginia, is performing the work with all Army Corps of Engineers personnel, using floating cranes, towboats, barges and support vessels. In addition, the specialized jacking guides will be used to secure and stabilize the miter gate while work is taking place. Because the 600-foot chamber will be used while work is being done on the 1,200-foot chamber, some delays are inevitable. Tows will have to be split with each half locking through one at a time. “Cannelton locked 52 million tons of cargo in 2016,” said Moulton. “The queue will build up and the time of delay will change daily.”