Pigeons Took Toll On Failed Bridge

Experts Say Buildup Of Pigeon Dung May Have Played Role In Deterioration Of Minneapolis Bridge

(AP)  Pounded and strained by heavy traffic and weakened by missing bolts and cracking steel, the failed Minnesota bridge over the Mississippi River also faced a less obvious enemy: Birds.

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 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 1987-1989 report.

In 1996, screens were installed over openings in the bridge's beams to keep pigeons from nesting there, but that did not 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 is not 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 was not 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.

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 wildlife biologist with the U.S. Department of Agriculture.

Meanwhile, the National Transportation Safety Board issued an update on its findings in the collapse Wednesday, saying investigators are looking at whether chemicals used in an automated de-icing system had any corrosive properties.

The state Transportation Department was not concerned about the system; in fact, the agency is planning to install a similar system on the replacement bridge, said Khani Sahebjam, a state transportation engineer.

The de-icing elements are inside the concrete deck, Sahebjam said, so he would not expect them to pose a structural problem.

[timantane]

Oh, poop!

[nutz12341]

How convenient!! I mean, you can''t sue a pigeon. If this is true, every single bridge in America is in immediate danger of collapsing.

[toolmangler-2009]

Posted by payasyougo at 02:42 PM : Aug 23, 2007


Are you saying that it was peasant pee not pigeon poop that precipitated the perpendicular plunge of this previously properly positioned portal?

[jt92202]

And who paid this expert to come up with this? WE THE PEOPLE!! I WANT MY MONEY BACK!!!

[sofi2hot]

AaaBee you hit that one on the head!!!

[aaabee-2009]

Poop, huh? Nope, ain''t buying it. The White House is still standing after 7 years of ***...

[jdubs63]

Oh PlEASE.... This is outrageous

[dylanxxv]

You got some strange rules cbs...We can say poop, but not c r a p?

[dylanxxv]

"Pounded and strained by heavy traffic and weakened by missing bolts and cracking steel, the failed Minnesota bridge over the Mississippi River also faced a less obvious enemy: Birds."


Never mind the missing bolts and cracked steel...Lets just focus on the bird ***...

[inventagod]

OH NO!!!
There is birdpoop on my windshield!
Do I have to leave my car at the light and buy a new one???
Or can I just wash it occasionally?
These ''Experts'' are full of poop, themselves.
Seems like stupid excuses...

[bareemperor]

First, a fire caused WTC7 to neatly fall into it''s own footprint...

Now birdshit brought down a steel bridge?

Bu$h science sucks.

[payasyougo]

This article has a misprint. It''s not pigeons its peasants. The peasants have contributed to the deterioration of roads and bridges by not forcing our politicians to spend the tax revenue on that for which it is collected. Road and bridge fee, gasoline taxes, vehicle registration "fees" (i.e. fee is a government synonym for tax).

[SIDNEYWILLIAMSMD]

Imagine that, the bridge was krapped on. "Dung in"
so to speak...I thought it was the war in Iraq...guess I was dung wrong.

[phydeux1]

Those stupid ghetto chickens! Not only do the poop everywhere, but then they go around stealing the bolts right out of the bridges!!! When will it stop?

Around here they put spikes on a lot of rooftops and ocassionally hire special exterminators to bring them down with trained hawks.

[rushman71]

Save the Whales!!! Shoot the Pigeons!!!

[sandy19731]

Ah! Another problem for the Amateur Ornithologist!
That''s me!

Spikes!
that''s my answer, Pigeons won''t land where there are spikes. Netting should be useful, too. No reason to poison them.

Also, one can buy poop-off (no kidding) from any pet bird supply store. Dissolves bird poop like magic.

[obiwan234]

Semi annual cleaning prior to inspections would just be good policy. This isn''t the only bridge in America with major problems, as far as the stated factors contributing to the bridge failure..."heavy traffic and weakened by missing bolts and cracking steel" ...and bird droppings.

Heavy traffic, proper bridge design should have covered that. Missing Bolts, cracks in the steel and bird droppings are as much human failure to repair the bridge and maintaining the structure for safety. Federal, state and county governments are responsible for this preventable tragedy.

[nothappyatall]

"Experts say the corrosive guano deposited all over the span''s framework helped the steel beams rust faster. "

Blame the birds for LACK OF MAINTENANCE, way togo!

FASTER doesn''t mean the pigeon krap was the cause, neglect and lack of a comprehensive maintenance program, as well as the design were the cause. If there was no pigeon krap there it would have collapsed at some point anyway the way it was heading.

[agnim]

"Pigeons Took Toll On Failed Bridge
Experts Say Buildup Of Pigeon Dung May Have Played Role In Deterioration Of Minneapolis Bridge"

Another idiotic ''expert''.
I wonder if he has someone in his family who could alert him to how full of *** he comes off to be? LOL

We fail to do UPKEEP, and turn around to blame the pigeons?

Do you know what this means?

IT MEANS THAT PEOPLE WILL FAIL TO DO ADEQUATE UPKEEP, BECAUSE THAT IS NOT FOUND TO BE THE PROBLEM.

[antoniof123]

What a bunch of carp. I had to say that....