SCIO — Shimanek covered bridge that spans Thomas Creek is expected to be closed for up to three weeks due to structural repairs, according to Linn County Roadmaster Darrin Lane.
Lane informed the Board of Commissioners by email Thursday morning that traffic will be diverted to Shimanek Bridge Drive.
“On November 10, members of the Road Department Bridge Maintenance Division were cleaning and inspecting the northwest corner of Shimanek Covered Bridge,” Lane noted. “Serious decay was observed and investigated. The nature of the decay is such that repairs must be made as soon as possible to prevent the bridge from damage due to its own weight.”
He added that the duration of the closure is unknown, but will probably be at least three weeks.
Lane added that his crew is completing a more thorough evaluation of the bridge’s structural members “in order to design temporary repairs that will allow the resumption of traffic over the bridge.”
Lane said the plan is to make temporary repairs that will allow up to 30 tons of traffic, which is the current load limit.
“We won’t know how much loading the temporary repairs will be able to support until early next week,” Lane said. “Manufacture and installation of the temporary repair parts will begin as soon as the design work is completed. The Road Department Bridge Maintenance crew will begin installing temporary shoring as soon as possible.”
Lane said the bridge is inspected every two years, adding that the county recently applied for $1 million in bridge funding to complete repairs on other areas of the bridge.
“The existing structural deficiencies that were previously identified were not significant enough to warrant a closure of the bridge,” Lane said. “The decay found this week on the northwest corner was not identified in previous inspections.”
Lane added that the county also will be requesting a modification of the previous funding application to be able to make permanent repairs in the decayed area.
It may take up to two years to get that funding, Lane noted.
Shimanek is the county’s newest and longest covered bridge, at 130 feet.
It is the fifth bridge — the fourth covered bridge — at the location. It features a Howe truss system and instead of being open-sided, is enclosed and is painted red. It’s portal or slatted.
The first bridge at the site was constructed in 1861 and was not covered. A covered bridge was built in 1891 for $1,150 and it was rebuilt in 1904. That bridge was washed out in 1921 and was replaced. In 1927, high water damaged the bridge’s piers, necessitating replacement.
Damage from the Columbus Day storm in 1962 resulted in the bridge being restricted to a 2-ton load of single-lane traffic, and the bridge was later destroyed.
The current bridge was constructed in 1966.