‘Rotten from inside out’
Lyon County to repair support beam for bridge over Three Mile Creek near Ghent
MARSHALL — A bridge beam has been discovered to be rotting from the inside out and will need to be replaced.
Aaron VanMoer, Lyon County engineer, told the Lyon County Board at its regular meeting Tuesday morning that the bridge over Three Mile Creek on County Road 65 northeast of Ghent has a structural problem that needs to be addressed.
“What’s happened is there is a structural element of this bridge that sits right below the deck, at one of the abutments,” VanMoer said. “It’s a timber beam and it’s essentially rotted from the inside out. The beam supports the bridge deck. We noticed it last year on a routine inspection.”
VanMoer indicated a photo that showed the beam with a tape measure sticking out.
“We can stick our tape measure a little over 2 feet inside,” he said.
VanMoer was told by inspector Andrew Kuehl that it’s fairly common and worth fixing so the whole bridge doesn’t have to be replaced.
The next step for VanMoer’s department was to get quotes for the beam repair.
“We had a hard time getting a contractor to quote us since it’s a smaller project and most of the bridge contractors are busy, but we did receive a quote from M&K (Bridge Construction) to replace this timber beam. It’s the only one received, but it does fall in the lines of the estimate from the engineer so I feel comfortable with the quote,” he said.
The repair cost is $28,825 and the commissioners voted to authorize it.
VanMoer said the cost is because of the complicated repair process, involving excavators and jacking up the bridge 2 inches to get the beam out and sliding the new beam in.
“It will take about a week,” he said. “We’ll have the bridge closed for a week.”
M&K Bridge Construction told VanMoer it will take about three to four weeks for the project to commence because it will take that long to get the material.
“It will be done before harvest, well before harvest,” he said.
Commissioner Rick Anderson asked if the timber beam could be replaced with a steel beam.
VanMoer said it’s not recommended.
“Timber beams provide a cushion,” he said. “It acts as a shock absorber.”
Commissioner Gary Crowley said he drove over the bridge recently after receiving information about the damaged beam and “it looks good” so he’s glad the whole thing doesn’t have to be replaced.
VanMoer added that the bridge was built in 1970, so it’s “a little newer. It has at least 20 years of life left.”