Back to the Minnesota Bridge Collapse [View All]

http://www.msnbc.msn.com/id/22663216/
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Undersized gusset plates in the Interstate 35-W bridge in Minneapolis were “the critical factor” in the bridge collapse last year that killed 13 people and injured 100, the National Transportation Safety Board said Tuesday.

Chairman Mark Rosenker said the plates, which connected steel beams, were roughly half the thickness they should have been because of a design error. Investigators found 16 fractured gusset plates from the bridge’s center span, he said.

The Minneapolis bridge was a steel-deck truss bridge that opened in 1967. Rosenker said it wasn’t clear how the design flaw made it into the bridge because investigators couldn’t find the design calculations.

Once they made it into the completed bridge, he said, there was little chance they would be noticed by inspectors.

There are about 465 other steel-deck truss bridges around the country. Rosenker said the safety board had no evidence that the deficiencies in the Minneapolis bridge design “are widespread or go beyond this bridge.”
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And they know this how?? Move along DUers -nothing to worry about until rhe next bridge collapses.