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Every winter, critical maintenance projects are completed at Rock Island District locks along the Upper Mississippi River. Several teams, comprised of Corps maintenance crews and contractors, are needed to tackle the work and ensure smooth operations by spring.
While some projects, like the one at Locks and Dam 14 in LeClaire, Iowa, require a complete dewatering of the lock chamber, others can be completed “in the wet,” meaning the lock chamber remains full of water during the process.
The largest and most noticeable project underway this winter is at Locks and Dam 14. This effort began with a dewatering in mid-January and will continue until mid-March.
“The site has not been dewatered in over 20 years,” said Aaron Dunlop, Operations Manager for the Mississippi River Project Office. “This dewatering will allow for critical inspections and much needed repairs.”
Key tasks being completed during this project include inspecting the chamber and critical lock components, installing a complex lower sill beam to facilitate future dewaterings and replacing the lock chamber bubbler system and embedded miter gate anchorages. The price tag for this effort is approximately $3.5 million and is being completed by a team of 20 in-house Mississippi River Project staff.
“These employees are accustomed to accomplishing these types of dewatering projects each year. The team is comprised of welders, lock and dam repairers, towboat operators, crane operators, divers, engineers and various other skillsets,” said Dunlop. “And we look forward to the opportunity to showcase these critical repairs when finished.”
Upriver at Lock and Dam 13 in Fulton, Illinois, a project is underway to rehabilitate one of the gearboxes needed for miter gate operation.
“The gearbox is original to the lock and dam site which was constructed in the 1930s and serves as a critical component that facilitates lock operability,” said Jeff Tripp, Lock and Dam Section Engineer.
The maintenance crew was tasked with removing the gearbox from service and sending it to a machine shop to be refurbished. Once refurbishment is complete, and the gearbox is reinstalled, it will continue to serve its role as a critical component to miter gate operation.
In addition to the gearbox rehab, a submersible dike repair project is also underway. This $3.5 million project includes concrete resurfacing of the submersible portion of the dike and riprap placement to prevent scouring and maintain reliability of the structure.
“The submersible dike serves as the damming surface to maintain Pool 13 as a part of the 9-foot navigation channel,” said Tripp. “This project is critical to ensuring navigation in the pool remains unencumbered.”
Another project is underway right across the street from Rock Island District’s headquarters building at Locks and Dam 15 in Rock Island, Illinois. This $11.2 million contractor-led project on the downstream guidewall of the main lock chamber is scheduled to be completed this winter. The project started in the 2018/2019 winter season and involves construction of several new reinforced concrete sections of wall, known as monoliths, which are founded on rock-socketed steel pilings.
“The original lower guidewall became unstable and required partial demolition which directly impacted navigation,” Tripp said. “The partial monolith demolition was executed by the maintenance crew in 2017, but was only an interim solution that reduced risk related to day-to-day operation of the lock. Once the project is complete, the guidewall will perform its original design function.”
The hydropower turbine, located inside the small building on the river wall of the auxiliary lock chamber at Locks and Dam 15, is also receiving attention this winter. During a previous inspection, it was discovered that some of the linkage components, which connect to the wickets, needed to be replaced. Motor shop machinists at the Mississippi River Project Office in LeClaire, Iowa, fabricated new linkages which will be reinstalled by lock personnel.
Downriver at Lock 19 in Keokuk, Iowa, work began in early January to replace a 27-foot tall by 110-foot wide vertical lift gate. This service gate is one of two vertical lift gates positioned at the upstream end of the 1,200-foot lock chamber.
“Both lift gates are operated by hydraulic machinery which serve as a moveable damming surface allowing barge traffic to transport goods along the Mississippi River,” said Tripp. “This replacement is an important step to keeping navigation moving on the river.”
In addition to the gate replacement, maintenance crews are also working on concrete resurfacing in the lock chamber and lock valve repair.
While maintenance crews are hard at work repairing the gates at the lock, a contractor, under the direction of the United States Geological Survey (USGS), is working this winter to install a temporary, experimental underwater Acoustic Deterrent System (uADS) on the downstream end of Lock 19.
USGS, in partnership with the U.S. Army Engineer Research and Development Center (ERDC), chose Lock 19 as a prime testing location to look at the potential for acoustic signals to deter Asian carp and native fish from moving upstream. This effort also seeks to understand and assess the engineering, maintenance and logistical considerations associated with long-term operations of a uADS in an active navigation channel.
If the deterrent is effective at controlling upstream movement of Asian carp with limited effects on native species, this or similar technology could be deployed at other critical locations to help prevent the spread of invasive Asian carp.
At the far southern reaches of the District, Lock and Dam 21 in Quincy, Illinois, and Lock and Dam 22 in Saverton, Missouri, are getting new embedded gate anchorages which serve as the upper connection between the miter gate and the lock wall. These anchorages are what allows the lock gates to open and close when a vessel passes though the lock. Both sites were still operating using their original anchorages from the 1930s.
Additionally, Lock 22 is getting mooring cell and upstream guidewall repairs this winter. A flat barge, known as a floating plant, which houses all the necessary tools and equipment needed for the repairs, is being used for this job. This specially designed work barge makes it easier for the maintenance crews to make repairs to areas not easily accessed from land.
“These repairs are critical because both structures are subject to heavy wear due to repeated barge impacts,” Tripp said.
While the brutal conditions of a Midwest winter may not seem like the ideal setting to perform such critical projects on the Upper Mississippi River, the timing allows for the least amount of disruption to the navigation industry.
“The maintenance crew is accustomed to working in the harsh elements to complete the scheduled work,” Tripp said. “They know the importance of our inland waterways and will do whatever they can to ensure this critical infrastructure lasts for generations to come.”
| Date Taken: | 02.23.2021 |
| Date Posted: | 02.25.2021 12:30 |
| Story ID: | 389750 |
| Location: | ROCK ISLAND ARSENAL, IL, US |
| Web Views: | 594 |
| Downloads: | 0 |
This work, Winter Maintenance Underway at Several Upper Mississippi River Locks, by James Finn, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
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