Thursday, August 09, 2007

MN Bridge

Listening to the radio last night, I heard a few things about the bridge collapse in Minneapolis that surprised me -- one, they finally have a navy salvage dive team going through the wreckage, and two, that the bridge had been classified as "structurally deficient" for almost two decades. Not that 'structurally deficient' was any particular reason for the bridge to fall -- hundreds of bridges in the US are in the same or worse shape.

The dive team wasn't really a surprise, I guess , but it took quite a while for them to be involved. The local rescue organizations simply don't have the right equipment or the right training to dive into the swift-moving water amidst the wreckage of the both the concrete and steel bridge, and the cars. There are still eight people missing.

Yesterday, rumors emerged that the problem with the bridge may have been something called "gusset plates", which are used to connect steel girders and are used in many bridges, not just the 35W bridge. There seems to be some concern that the bridge was under-designed from the start. They are even suggesting that the additional weight of equipment that was being used to repair the decking of the bridge may have been enough to cause the failure in these bolted plates. But the bridge has been cited for years as having severe problems -- corrosion, cracks, even missing bolts.

It's certainly making me look at every bridge I drive over or under with a much more critical eye.

1 comment:

Iowa Gardening Woman said...

I'm wondering about the bridges I drive over also. Every bridge over the Mississippi is old, I have driver over the one in MN many times. I know it will be on my mind my next trip over the Mississippi.