Posted on 08/22/2007 2:14:54 PM PDT by Responsibility2nd
ST. PAUL, Minn. (AP) - 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: pigeons.
Inspectors 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.
In 1996, screens were installed over openings in the bridge's beams to keep pigeons from nesting there, but that didn't prevent the building of droppings elsewhere.
Pigeon droppings contain ammonia and acids, said chemist Neal Langerman, an officer with the health and safety division of the American Chemical Society. If the dung isn't washed away, it dries out and turns into a concentrated salt. When water gets in and combines with the salt and ammonia, it creates small electrochemical reactions that rust the steel underneath.
"Every time you get a little bit of moisture there, you wind up having a little bit of electrochemistry occurring and you wind up with corrosion," said Langerman. "Over a long term, it might in fact cause structural weaknesses."
Langerman emphasized that he wasn't saying pigeon dung factored into the collapse of the 40-year-old bridge. "Let's let the highway transportation and safety people do their job," he said.
The problem is familiar to bridge inspectors everywhere.
The Colorado Department of Transportation spent so much time cleaning pigeon manure off bridges that it is embarking on a two-year research project looking for ways to keep pigeons away from its spans.
"It can be damaging to our structures because it's slightly acidic and it has other compounds in it that can dissolve especially things like concrete," said Patricia Martinek, the agency's environmental research manager.
Pigeon guano isn't just a danger to the bridges.
In the Denver area, the Colorado DOT pays outside environmental specialists to clean bridges wearing full biohazard suits with respirators because of heightened fears about bird flu and other diseases, said Rob Haines, who supervises maintenance there.
Keeping pigeons off bridges usually requires a multi-pronged strategy that can include netting to block holes and surfaces, spikes to keep them from landing, and sometimes poisoning, shooting or trapping the birds, said John Hart, a Grand Rapids, Minn.-based wildlife biologist with the U.S. Department of Agriculture.
The problem is that pigeons are naturally drawn to bridges and tall buildings since they're descended from cliff-dwellers, said Karen Purcell, who heads Project PigeonWatch at the Cornell Lab of Ornithology. Bridges offer shelter from predators and flat surfaces for nesting and roosting.
"It's a nice fit for them," Purcell said.
Meanwhile, representatives of Minnesota and North Dakota met Wednesday to discuss repairs to a highway bridge that was closed Tuesday after a crack was found in a girder support bracket, said Les Noehr, a district engineer for the North Dakota Department of Transportation. The 53-year-old bridge over the Red River between Robbin, Minn., and Drayton, N.D., would not have collapsed even if the cracked bracket had failed, said Minnesota's state bridge engineer, Dan Dorgan.
The span is scheduled for replacement in 2009. The nearest alternate bridge is 17 miles away.
The I 35 bridge fell down because of Pigeon Poop.
Sounds reasonable.
I wonder how the Brooklyn Bridge is still standing?
BIG Pigeon, pigeonzilla.
poop ping
Makes at least as much sense as saying that Moose burps are contributing to global warming.
How many minutes will pass before the moonbats find a way to blame Bush? Not many!
—it happens!
He keeps boids. Dirty... disgusting... filthy... lice-ridden boids. You used to be able to sit out on the stoop like a person. Not anymore! No, sir! Boids!... You get my drift?
Pigeon poop comes from global warming!
Let me try, if Bush hadn’t been pushing for drilling in Anwar, then other animals could have joined the Caribou and allowed space for the pigeons to fly freely as opposed to having to rest on cold rusty bridges in Minnesota. How’s that?
Winchester used to make a 12 gauge Pigeon Load (3 1/4 dr. equivalent of powder - 1 1/4 ounces of shot). Seems like just the thing for preventative maintenance for bridges.
Hah! Libs started Blaming Bush from the get-go.
Blaming begins in Minneapolis bridge collapse
Posted by NormsRevenge
Boortz: THE BLAME GAME BEGINS (re: bridge collaspe)
Posted by yankeedame
Katrinafying Minnesota's Disaster
Posted by Kaslin
Flying rats.
PETA would never approve.
Harming birds? Are you crazy?
Better a bridge should fall with 8 dead and billions in damages, than a pooping pigeon be harmed.
Anyone who has ever shoveled chickens*** can tell you that. Anyone who's ever driven by ne of those high concentration battery egg farms might even detect the faint scent of acid and ammonia in their nostrils.
But I also have to observe that pigeon poop is fairly common to all big city structures, including bridges.
It was always my opinion that it is the weight of the poop and not its corrosive effect that collapsed the bridge. Pile enough poop on the Brooklyn bridge and see what happens.
Poop happens.
Poor maintenance? Naw it was the poop!
But they taste like...chicken!
Yeah, but the real problem is the poop between the ears of politicians spending on socialist cwap instead of infrastructure upkeep.
And the poop headed voters who put them into office year after year so they can keep cwapping out the socialist welfare goodies.
Good point, LOL. Nevermind the fact that Minnesota is exposed to 120 degree temperature variations over the course of a year. Forget all the snow and icing and all the salt that has likely been spread on that bridge. It was pigeon doodie!
And they chose to write about the pigeon poop.
I’m stinking with “Bush’s fault.”
Yeah ... it’s a racist assault on all of us Avian-Americans ... These filthy mammals will be hearing from the National Association for the Advancement of Feathered People, I can tell you that!
Great movie.
L
That might also explain the subprime mortgage collapse.
Hmmm Pigeon Pooo and a deicer too!
“This bridge features an anti-ice system. A series of PVC pipes carries a deicer fluid to outlets that are drilled into the deck of the bridge. When the temperature for ice is right, the deicer fluid is pumped onto the bridge deck. This system has proven to be successful enough that it is being installed on other bridges in Minnesota.”
I wonder how corrosive the de-icer system was...
http://www.visi.com/~jweeks/bridges/pages/ms16.html
At least it wasn’t Bat Guano, Buck (Turgidson).
Apparently pigeons kept the book "Pooping on Minnesota Bridges in 12 easy lessons" secret.
...and that, oddly enough, they started pooping on in it after Jan. 20, 2001.
To believe the pigeon poop theory, you'd have to think it wasn't corrosive enough to dissolve pigeon poop.
. . .pigeon poop happens. . .
And they chose to write about the pigeon poop.
Beats blaming the labor unions and government employees for incompetence
Also from the same trip we went to breakfast in a open air Denny's by the pier above a ABC store.... again signs don't feed the birds.
Several pigeons we’re interviewed, all said better gun control would have avoided this.
“I’m not a madam, I’m a concierge.”
“the pigeon problem is one of many factors that dogged the structure”.
Next, we’ll hear about the DOT ratting on the engineers who designed the bridge. Somebody will be found to be lion about their involvement, robin Peter to pay Paul, that kind of thing. Who knows what kind of lynx will show up once the investigation is underway, gibbon the kind of responsibilities involved.
- from FReeper jim trent's post I-35W Minnesota Bridge Inspection Report [opinion] on August 9, 2007.
trade vick to vikings
teach pigeons to fight
I'm sending them my business card: "Have Gun Will Travel".........Beeman Kodiak .22 cal. pellet with Bushnell scope.............
Deadliest gun in my cabinet considering all the rabbits and squirrels I have been able to eliminate in my condo complex which bans the shooting of any firearms whatsoever.......You can do one shot/one kill rabbit head shots all day long out to about 35/40 yards, maybe even longer but I haven't had to shoot further distances........
that is easy.. the warmer it is the faster corrosion takes place.
One of the breakdown products of pigeon doo-doo is nitric acid and it is big time corrosive.
Good name for a band!
Link:
Minneapolis I-35W Bridge Collapse Failure Analysis
http://www.freerepublic.com/focus/f-news/1884493/posts
What caused the initial component(s) to fail could,
of course, still be pigeon dung, or the de-icing
chems, or ...
Hmmmmmmm.....I think Congress and Washington DC is in trouble from all the h*rsecr@p and b*ll$h!t.
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