Free MMORPG Forums

Xynh · 08-23-2007, 11:04 AM

Quote:

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 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.

"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, 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 wasn't 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 wouldn't expect them to pose a structural problem.

The automated system was triggered by weather conditions and kept the state from having to send crews to spread de-icing chemicals, Sahebjam said.

Source: http://news.yahoo.com/s/ap/20070822/...llapse_pigeons

shevrock · 08-23-2007, 11:08 AM

i can say one thing. ROFL

ArutoXX · 08-23-2007, 11:27 AM

i agree its t3h ROFL copter

hobolord · 08-23-2007, 11:55 AM

i helped to

doing it for the team

Bacn · 08-23-2007, 11:57 AM

So are pigeons terrorests now?

Coolest Name Ever · 08-23-2007, 12:09 PM

Quote:

Originally Posted by Bacn

So are pigeons terrorests now?

Yes, yes they are

M1nGs3N4yuk1 · 08-23-2007, 12:10 PM

Quote:

Originally Posted by Bacn

So are pigeons terrorests now?

Yes they are my friend. They sure are.

Time to bring out my machine gun and show them pigeons whos stronger. Their poops or my machine gun. 8)

shevrock · 08-23-2007, 01:02 PM

Bacn you simple mind is a guiding star to us all.

Raiyne · 08-23-2007, 01:19 PM

Lmao... no wonder I saw not one, but two dead pigeons along the road the other day.

Slade · 08-23-2007, 01:43 PM

Quote:

Originally Posted by shevrock

Bacn you simple mind is a guiding star to us all.

Tch, yeah if we listen to Bacn then we'll all think being a furry is good, clean and wholesome. Oh shit, Stop me now.

Can't believe people make news articles about this shit. "Oh it's curious and funny lolol." It's pointless, and shows our low the media goes to get a story that the idiot demographic will find 'interesting'.

08-23-2007, 11:08 AM	#2 (permalink)
shevrock SuperKenshin's Servent Join Date: Dec 2006 Location: not sure tell me when you figure it out. Posts: 1,093 Reputation: 10	i can say one thing. ROFL __________________ What happens when you stop to smell the roses, And their dead? Torrin J. Mckee

08-23-2007, 11:27 AM	#3 (permalink)
ArutoXX Luigi’s Pizza Join Date: Aug 2007 Posts: 138 Reputation: 0	i agree its t3h ROFL copter __________________ METALLICA 4EVA well at least for today! My fave bands: A7X, Metallica, Iron Maiden, Disturbed and you know the sort of thing Currently playing: Soldier Front, Dark Messiah, (Drift City) BF2 and some other random ones

08-23-2007, 11:57 AM	#5 (permalink)
Bacn It's Bacon!!! Join Date: Oct 2006 Location: Dogenzaka Hill Posts: 7,868 Reputation: 228	So are pigeons terrorests now? __________________ First Came The Question Then Came The Answer

08-23-2007, 01:02 PM	#8 (permalink)
shevrock SuperKenshin's Servent Join Date: Dec 2006 Location: not sure tell me when you figure it out. Posts: 1,093 Reputation: 10	Bacn you simple mind is a guiding star to us all. __________________ What happens when you stop to smell the roses, And their dead? Torrin J. Mckee

08-23-2007, 01:19 PM	#9 (permalink)
Raiyne Feedbacker Join Date: May 2006 Location: The Middle of the Stairs Posts: 13,390 Reputation: 126	Lmao... no wonder I saw not one, but two dead pigeons along the road the other day. __________________ Everytime I post, I think Murph is about to BROFIST me. -- Loric Last.fm Hey Raiyne

08-23-2007, 11:55 AM	#4 (permalink)
hobolord Roon's Rogue Join Date: May 2006 Location: australia Posts: 4,310 Reputation: 68	i helped to doing it for the team

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode