That pigeons have melted steel.
Richfisher in the comments on Aug.8;
I sand blasted and painted steel bridges and water towers through high school and post secondary summer breaks. I have next to zero hearing left to show for it and two degrees.The rust created from a pidgeon nest left in the same spot for about 5 years is unbelievable, it can erode a one inch thick steel rivet plate by about half it's thickness in extreme circumstances.
Box beam bridges like this one are difficult to blast properly, because you can not properly point a stream of sand and air directly at rust spots up inside the beam.
Some inspectors are afraid of heights and will not go out on scaffold rigging to properly inspect crucial junctions for paint thickness or blast quality . I've never seen an inspector in a bolsons chair,(window washer) ever.
Now add double crested cormarants roosting on the beams.
My guess is it collapsed because of the rust.
Pounded and strained by heavy traffic and weakened by missing bolts and cracking steel, the failed interstate bridge over the Mississippi River also faced a less obvious enemy: Birds, specifically pigeons.Posted by Kate at August 23, 2007 12:55 AMInspectors began documenting the buildup of pigeon dung on the span near downtown Minneapolis two decades ago.
Experts say the corrosive guano deposited all over the Interstate 35W span's framework helped the steel beams rust faster.
Although investigators have yet to identify the cause of the bridge's Aug. 1 collapse, which killed at least 13 people and injured about 100, the pigeon problem is one of many factors that dogged the structure.
"There is a coating of pigeon dung on steel with nest and heavy buildup on the inside hollow box sections," inspectors wrote in a report.
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I phoned this one in from a special phonebooth.
Posted by: Alfred Hitchcock at August 23, 2007 7:20 AMPigeon dung was never a problem before global warming.
Posted by: Richard Ball at August 23, 2007 8:52 AM*
nah... i'm still going with the "zargon rays" emanating
from dick cheney's extra-terrestrial heart.
*
Posted by: neo at August 23, 2007 9:32 AMgood thing they didn't have traffic and pigeon problems to blame the collapse of WTC 7 on....but I can see it coming in a report rewrite if there ever is one.
Posted by: WL Mackenzie Redux at August 23, 2007 9:38 AMAlthough bird crap is acidic and promotes rust (you want to wash it off your car double-quicktime,) those beams are what? Inch thick? Two?
Unless the bridge used cheap, sub-standard steel or is more than 100 years old, I doubt rust would be the problem...
Posted by: Warwick at August 23, 2007 9:39 AMThe bridge collapse was caused by Bush.
Halliburton was running out of contracts and needed a bridge re-building project to fill in time. Mossad bred a certain type of pigeon that
exudes special acidic droppings just for this type of plan. The CIA purchased them from Mossad
and let them loose near the bridge around the time of 9/11. Does anyone know if any Jews died in that bridge collapse, or were they all told to stay home that day?
Thanks for posting the reference to me holding the so called "information firehose", for a second there, Kate.
Albeit, I've always thought of the characterization of the information flow on the internet as more of a "sandblasting hose" effect (gradually blasting off the weakening corrosion on truth, to expose the reality and strength of bright gleaming steel underneath)
(Sorry, long hours holding that hose)
also
There is some groundbreaking rust research going on in San Mauro, here's the synopsis from the learned delegates. ;^)
http://www.youtube.com/watch?v=e0YFJvWmoes
Oh Crap!
Posted by: OMMAG at August 23, 2007 10:55 AMI had no idea George W. Bush and Karl Rove were pigeon breeders.
Posted by: Sheldon Kotyk at August 23, 2007 12:06 PMATTACK OF THE STEEL EATING KILLER PIGEONS. AHH HERE WE COME SQUAWK SQUAWK WERE THROUGH BEING SO NICE WE BIRDS HAVE HAD IT WITH THE ECO-FREAKS AND THE DAMN WIND TURBINES WERE GOING TO EATS YOUR WIND TURBINES THENS WE EATS YOU SQUAWK SQUAWK SQUAWK
Posted by: spurwing plover at August 23, 2007 3:02 PMSince we read it here on SDA 2 weeks ago, could someone please remind me once again why we need the MSM.
Posted by: DrD at August 23, 2007 3:41 PMSure im a spurwing plover but im leading these mad birds SQUAWK SQUAWK
Posted by: spurwing plover at August 23, 2007 3:44 PMMaybe someone should review Alfred Hitchcock's THE BIRDS. That movie could have been a prophetic message warning about us about confining birds in a cage. Perhaps the NRA could start a campaign to eliminate some 'city chickens'. Urban bird blight problem solved by lead (oops that has been outlawed) shot.
Posted by: Farmerboy at August 23, 2007 4:38 PMOk, who smuggled the pigeons into NA? Maybe dijion can make a retroactive law to combat this AGW issue.
http://www.fws.gov/migratorybirds/issues/nonnative/EvidenceofOccurrence.pdf.
Posted by: ural at August 23, 2007 11:05 PMI expect the steel used years ago was not galvanized, that would cause it to rust more quickly.
The second narrows bridge in Vancouver was upgraded by lifting the deck and melting zinc directly onto the horizontal steel beams that were being affected by road salt dissolving in rain and getting into cracks in the roadbed.
The bridge would not have rusted in the usual way from pigeon poop. The poop is acidic and would have "rusted" the iron into soluble ferric compounds instead of the usual red ferrous rust we all know and hate. Moreover, the layers of pigeon poop would make a good home for iron-eating bacteria, which also 'eat' iron into soluble compounds. Think of the bridge beams as undergoing an acid drop torture. (No not THAT acid!).
Posted by: newbury at August 24, 2007 4:23 PMSome people use bird poo as fertalizer its called GUANO
Posted by: spurwing plover at August 24, 2007 6:01 PM