Experts Tie Pigeon Dung, Bridge Collapse

[Ghost in the Machine]

Experts Tie Pigeon Dung, Bridge Collapse
Published: 8/22/07, 5:46 PM EDT
By MARTIGA LOHN

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.



"There is a coating of pigeon dung on steel with nest and heavy buildup on the inside hollow box sections," inspectors wrote in a 1987-1989 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.

http://home.bellsouth.net/s/editorial.dll?pnum=1&bfromind=7434&eeid=5369135&_sitecat=1522&dcatid=0&eetype=article&render=y&ac=3&ck=&ch=ne

[liberal N proud]

1. Something stinks here

Pigeon shits, bridge falls?

They will try to sell you that bridge too.

[OrangeCountyDemocrat]

2. What A Fucking Country

That article is a joke, right? Tell me it's a joke.

BLAME THE BIRDS!!!!!!

IT'S THE PIGEONS FAULT!!!!!!!!!!!!!!!!!!

LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[WinkyDink]

3. Al Qaeda pigeons!

[porphyrian]

12. Poo of mass destruction. - n/t

[proud patriot]

16. LOL

:rofl:

[malaise]

21. Brilliant

:rofl:

[Deja Q]

4. One would have to be wading hip deep in pigeon poo for it to have THAT much an effect...

Maybe the birds scooped up their poo and slung it at the beams?

[The Straight Story]

7. It's because they ate food from modified crops, and global warming too

:rofl:

[Deja Q]

17. Yeah, the corrosion from the de-icing system had nothing to do with it.

All those pigeons ganged up on us!

:scared:

[Gregorian]

5. Oh man. That was my prediction.

I called it corrosion. Then I read that exact line in the inspection report that is quoted here. It's a bit hard to believe considering the thickness of the steel. But it had plenty of time. Depending on the geometry and bird species, there are many other bridges out there with this problem. That isn't to say they will fail. We still don't know what caused the bridge failure. I'm sure we'll find out.

I also have my suspicions regarding the loading of the bridge at the time, due to maintenance. Just a hunch. We'll see.

We're frittering away our kingdom on war toys. What a pathetic joke.

[napi21]

6. Of course that's not the ONLY problem, but it IS true. Pigeon dung

is extremely acidic and corosive on steel and concrete. It wasn't the only cause that weakened the bridge, but it was a contributor. The reason for the collapse was lack of attention to needed maintenance!

[MnFats]

8. there is some thought that the anti-icing chemicals sped the corrosion..

NTSB is one of few federal agencies I have confidence in.
I think they'll get to the bottom of this...

[Ezlivin]

9. Too bad we killed off the passenger pidgeon - this is their revenge

[TreasonousBastard]

10. Laugh if you must, but pigeonshit was a major problem for...

the Brooklyn Bridge, among many others, and cost millions to deal with.

Birdshit is corrosive and while it's worse on suspnsion bridges, it attacks metal. Bridges are designed to certain loadbearing specs with a safety factor built in-- if the steel is simply weakened enough, the bridge will fail.

[shraby]

11. Isn't that one of the reasons for inspections and repairs???

[Mist]

14. Right--it's not so much a bird shit problem as a lack of dealing with the problem. nt

[JHB]

26. And when localities have a budget crunch (like from "old economy"-industries going overseas)...

...and reducing their tax base, what's one of the first things to go?
Stuff that won't show for years, like infrastructure maintenance.

And once out of the habit, do the maintenance crews ever get replenished?
Nope. At least, not until something big falls down or comes close to it.

[zabet]

13. Probably some..

terrorist faction of pigeons tied to the terrorist pigeon that bombed
dumbya recently while he was giving a speech.

Craps of mass destruction!!! :rofl:

[Spinzonner]

15. Sure sounds like a load of ....

[OrangeCountyDemocrat]

18. Of Course The Jackhammer Work At Rush Hour Was Insignificant

Which was more responsible?

Pigeon Poop?

Jackhammer Work On Bridge During Rush Hour Traffic?

[Tesha]

22. Pigeon poop. (No joke) (NT)

[KT2000]

19. Yeah - it's called the ENVIRONMENT

something the wingers choose to believe does not exist if it should be an inconvenience or expense.

I guess they prefer to look to fairy tales to support their ignorance and make the rest of us take their chances.

[Ghost in the Machine]

20. AM kick...

[bleedingheart]

23. Hey folks...it can be a contributing factor...the problem is that the bridge

could have been protected with frequent cleanings, sandings and a good old fashioned coat of paint....

[bdamomma]

27. ............

:thumbsup:

[Javaman]

24. Why does pigeon shit hate america? nt

[Wiregrass Willie]

25. The talk radio types will be running with this all day

Beginning with Limbaugh at noon Eastern. I seem to remember that in the early 90s this same crowd tried to sell the idea that bovine splatter caused global warming.