Lockport Lock To Close Seven Weeks For Pintle Repairs

Lockport Lock, lllinois River Mile 291, is scheduled to close March 31 through May 19 next year to replace cracked pintle sockets, temporarily closing a key section of the route between the Mississippi River and the Great Lakes, including the city of Chicago.

Locks on the Illinois Waterway have single chambers, so when one lock is out of service, the entire system is interrupted.

During a scheduled dewatering for vertical lift gate installation that began January 28, 2025, crews found that the pintle sockets—which act as the bottom hinge for the lower miter gates—were cracked.

“We would classify it as essentially a complete failure,” said Michael Walsh, chief of the Waterways Project Office for the Chicago Engineer District. “They had cracked all the way through.”

These components are normally submerged, so the damage was not known until the dewatering. Following an evaluation, a team of engineers proposed and carried out an innovative temporary repair, wrapping the cracked pintle castings with a carbon fiber-reinforced polymer, which Walsh described as akin to a Band-Aid.

That repair meant the lock was able to reopen April 4, less than a week after its originally scheduled reopening, and to continue to operate until new pintles could be fabricated.

Instrumentation attached to the gates at the time of the temporary repair have indicated no significant movement or shifting, Walsh said.

“So far everything looks really good,” he said. “We’ll know for sure when we get the chamber dewatered at the end of March.”

Investigation into the cause of the cracking determined that contact blocks were not making complete contact between the gate and wall when the lock gates were closed. The blocks are designed to transfer the load of the water onto the entire structure and not just the gate.

“This time we will actually remove the lower miter gates,” Walsh said of the repairs. “We will have to pull them out of place. We’ll have to modify the bottom of the gates a little bit to accept the new sockets. We’ll make weld repairs on the gates, and then, while the gates are out, the quoin blocks will be replaced. Then there will be a final fit to make sure tolerances and clearances are correct.”

Delivery of the two new pintle sockets is expected in January. Rock Island Engineer District staff and assets from both the Illinois Waterway fleet out of Peoria and the Mississippi River fleet out of Le Claire, Iowa, will complete the work. The crane Quad Cities will lift the gates, which weigh more than 300 tons each.

“A lot of our schedule was based on the need to get in there and do the repairs,” Walsh said, while adding that that the Corps reached out to industry to try to determine the best time for scheduling while also not adding to risk by delaying the repairs. The final schedule keeps in mind the needs of the towing industry and also area refineries that need to schedule outages, Walsh said.

“Unfortunately, when you have a single-chamber lock, there’s really no good time for everybody to shut down and get this work done,” he said.

Walsh anticipates that the work could create some issues for the recreational boating community as boaters on the Great Lakes may be looking to move their vessels upriver and back into marinas on the lakes during the planned closure.

While any spring high-water issues shouldn’t affect the repair schedule, Walsh said high winds could limit crane mobility, and spring storms also create the potential for lightning delays.

“Weather is that one thing out there that you can’t predict, no matter how much you plan,” he said.

He asked for patience while crews complete the repairs, which could prevent unscheduled closures in the future.

“We completely understand that no closure, planned or unplanned, is ideal, and that it does have some impact on folks,” he said. “We appreciate everyone’s patience as we perform these critical repairs.”

Featured image caption: When the Lockport Lock chamber on the Illinois Waterway was dewatered to replace a vertical lift gate in March 2025, crews discovered that the pintle sockets were cracked. The lock is scheduled to close March 31 through May 19 for new pintle sockets to be installed. (Photo courtesy of the Chicago Engineer District)