Following a historically late start to the navigation season in 2014, Mother Nature once again showed who’s in charge, giving the region a shot of cold air and shutting down navigation earlier than anticipated. This worked in favor of the district’s maintenance and repair section, based out of the Fountain City, Wisconsin, service base.
Every winter, the St. Paul District takes advantage of the iced-over river to shut down a lock completely and dewater the lock chamber to perform a laundry list of maintenance items. The lock in the spotlight this winter is Lock and Dam 5A, located on the Wisconsin side of the Mississippi River, two miles upstream of Winona, Minnesota. While this year’s list of maintenance items is similar to previous years, consisting of repairs to concrete, miter gates and machinery, Lock and Dam 5A does present different challenges.
Unlike most lock and dam facilities, the lock chamber and lock house at Lock and Dam 5A are physically located on an island in the river. While all the heavy equipment needed to perform the work is barged onsite prior to the river freezing, extra logistic details had to be taken into consideration.
Bob Edstrom, project manager for the maintenance, said one such exception that needed to be addressed for this project is how to get wet concrete across the river to the lock chamber. The solution was to load a truck onto a barge immediately downstream of the dam where the river rarely freezes due to the constant movement of water created by the spillway. The truck and barge would then be moved across the river to the lock chamber where the cement would be offloaded. He added the facility also has a crane on tracks situated atop the dam that can be used to move materials from the landside to the lock chamber.
Another logistic concern was safety and responding to an emergency.
“While safety of our crews and the public is always a top priority, one thing we did differently in preparation for this winter’s maintenance is orientate first responders who may be called out in an emergency,” described Mark Beseler, lockmaster for Lock and Dam 5A. “They can’t drive right up the lock house or chamber like they can at other facilities.”
Beseler also stated that there is a helipad located adjacent to the lock house that was recently upgraded to improve safety and security.
A pleasant change to the project this year has been the milder weather, at least initially. Despite the early cold snap that closed the river to navigation and allowed maintenance crews to start early, the weather has been working in the district’s favor. “Our guys are used to working in the extreme cold while doing our winter maintenance projects,” stated Scott Uhl, maintenance and repair section supervisor. “This year’s milder temperatures have been a pleasant change.”
Uhl added that working on the Mississippi River in the winter is still cold.