Cranes lift historic Minnesota bridge from its crumbling perch

Cranes lift both ends of the Kern Bridge
Cranes lift both ends of the Kern Bridge off of its abutments along the Le Sueur River south of Mankato, Minn., on Thursday. Find more photos at www.mankatofreepress.com.
Pat Christman | Mankato Free Press

A southern Minnesota bridge nearly as old as the state itself is on the road to a new home, after being delicately moved from its precarious perch on Thursday.

Crews using a pair of cranes carefully lifted the 147-year-old, 189-foot-long Kern Bridge in one piece, off its crumbling abutments along the Le Sueur River and alongside a nearby town road.

"We were all kind of holding our breath," said Lisa Bigham, state aid engineer for the Minnesota Department of Transportation's District 7. "It took a while to get everything kind of in place, the cranes to be positioned where they needed to be. Then, we were just kind of watching. And then, all of a sudden you could see air in between the bridge and the abutment. And it actually went very smoothly.”

"I was talking to one of the workers afterwards," she said. "Everyone was really happy — and this worker said, 'Yeah, it went as smooth as butter.' "

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The 189-foot-long Kern Bridge sits on the east side of the Le Sueur River
The 189-foot-long Kern Bridge sits on the east side of the Le Sueur River after being moved from its failed limestone abutments on Thursday morning. The historic bridge will be disassembled and preserved until a new home can be found.
Pat Christman | Mankato Free Press

The wrought-iron bridge now will be disassembled and stored in shipping containers, awaiting reuse somewhere in the state — perhaps along a bike-pedestrian trail.

"The pieces will be kept safe and dry," Bigham said. "And so then whoever gets to take this bridge in the future, will be able to put the pieces back together and they'll have a really cool bridge."

A view of the Kern Bridge in its original location
A view of the Kern Bridge in its original location spanning the Le Sueur River south of Mankato, as seen in fall 2019.
Courtesy of Minnesota Department of Transportation

Graceful and functional

The Kern Bridge had spanned the Le Sueur River south of Mankato, Minn., since 1873, just 15 years after Minnesota became a state.

Also known as the Yaeger Bridge, it carried people, wagons and farm animals, then cars until being closed to traffic in the early 1990s.

MnDOT reported that it’s the only remaining example of a "bowstring arch through-truss" bridge left in Minnesota, and the longest remaining in the United States. It's listed on the National Register of Historic Places.

"It's graceful looking and beautiful, but it's so functional," Bigham said, with the wrought-iron pieces all pinned together.

The crumbling east abutment of the Kern Bridge
The crumbling east abutment of the Kern Bridge is seen in June 2019 along the Le Sueur River south of Mankato.
Andrew Krueger | MPR News

With the bridge's limestone abutments crumbling further with each passing year, plans were launched to rescue and relocate the span. It was owned by South Bend and Mankato townships in southern Minnesota, the removal project was managed by Blue Earth County, MnDOT will store the bridge and solicit plans for a new home, and federal money will be available to cover 80 percent of the relocation cost.

"We've got all levels of government working together on this," Bigham said.

Crews spent a lot of time preparing the site, including placing fill in the river to serve as a crane platform; that fill will now be removed. Carlton Companies of Mankato was the contractor for moving the bridge, with a bid of $595,660.

The Kern Bridge is seen after being moved
The Kern Bridge is seen after being moved from its crumbling abutments along the Le Sueur River south of Mankato. The 147-year-old bridge will be disassembled and stored, awaiting reuse in another location.
Courtesy of Blue Earth County

MnDOT will start soliciting ideas for reusing the bridge in a way that preserves its historical integrity. Bigham said she'd like to see it cross over water, as it did in its original location.

"The biggest criteria is whoever takes it would need to ensure that when it gets put back up, it would be re-listed on the National Register of Historic Places. And it needs to be functional as some kind of a pedestrian or bike crossing," she said.

"It's been kind of a local attraction for quite a few years," she said. "And so, it will be really nice if it can be put back up and become an attraction in the future."