The water is freezing earlier than usual this year on the Mississippi River, making navigation difficult for tugboats. Lock and Dams chief Dennis Shannon says some parts of the Mississippi don’t usually freeze up until January — but this year that’s already happened at locks near Dubuque. “The ice is 100 percent covered on the river, and it’s about 10 inches thick. It’s stationary ice,” Shannon says.
He says that’s a lot of ice to get through for a single tugboat. “If traffic is passing this time of year, they typically will travel in pairs,”Shannon says. “If one of them gets in some kind of trouble they’re there to help each other out.”
When ice builds up in the lock chamber they have to put restrictions in place. “What happens is the tow is coming down the wall and is pushing ice in front of it. A 15-barge tow will take about hour and a half to lock. In winter conditions, that will change to about a minimum of four or five hours,” Shannon says. Shannon says the ice usually breaks up around March, so tugboats will be able to ship goods like fertilizer to farms up north.