Gusset plate worries strike a 4th bridge in Upper Midwest

By PAUL WALSH, Star Tribune

Last update: May 12, 2008 - 10:17 AM

Another bridge in the Upper Midwest is having trouble with its gusset plates, this one at least the fourth since last summer's bridge collapse in Minneapolis.

This one is Yankton, S.D., about 100 miles southwest of the Minnesota border.

A 10-ton gross weight limit is now in effect on the Meridian Bridge on Hw. 81 over the Missouri River in Yankton, the transportation officials in South Dakota and Nebraska said.

Vehicles heavier than 10 tons now are finding alternate routes over the Missouri, where it flows between South Dakota and Nebraska. The restriction does not apply to passenger vehicles.

A recent routine inspection revealed that "corrosion on the gusset plates had progressed to a point that heavy load restrictions are warranted," the transportation officials said.

The corrosion was detected several years ago on a routine bridge inspection "and had been periodically monitored ever since," the officials said.

Monitoring of the bridge will continue while temporary repair options are being investigated.

A new Missouri River bridge crossing in Yankton is under construction and scheduled for completion in the fall.

Last week in Duluth, two traffic lanes on the city's main bridge to Superior, Wis., were closed because of concerns about the gusset plates. The plates, 16 in all, will be bolstered with additional steel over the next few weeks, with all work and inspections expected to be completed on the Blatnik Bridge by mid-June. Two lanes remain open.

In January, federal investigators said undersized gusset plates played a role in the Aug. 1 collapse of the Interstate 35W bridge in Minneapolis. Gov. Tim Pawlenty ordered load recalculations of 25 steel truss bridges in Minnesota, including the Blatnik Bridge and the recently closed DeSoto Bridge on Hwy. 23 in St. Cloud. The review is expected to be finished by July 1.

Paul Walsh • 612-673-4482