Here’s a new theory for the I-35W bridge collapse–blame the pigeons. Apparently “piles of pigeon guano” may have impeded inspectors from discovering the true state of the bridge:
Heaps of corrosive pigeon droppings obscuring parts of the bridge’s steel supports have been a bane to inspectors at least since 1994, documents show. The birds were nesting in welded steel box sections of the superstructure, gaining access through the same holes used by inspectors to peer inside to look for cracks. In 1999, MnDOT covered the inspection holes with plastic screens, but the problem persisted.
“The interiors of the box members have severe pigeon debris,” MnDOT workers wrote in their 2006 inspection report. (Star Tribune
Sounds ridiculous, but pigeon droppings have proved a major problem at this bridge. Not only did they stop the inspectors from seeing there, they were probably causing damage themselves. Bird droppings are very acidic and could have very well been corroding the structure, compromising the bridge.
In my humble opinion, they could have just put some bird spikes down and not had to worry about this at all.
Forget the spikes, Tom. I checked your site and I’d have gone for the fox. ;-)
Did you see the 3D coyote? That’s a brand new product, actually. I think I’m taking one home with me, just to leave on the porch.