Posted on 08/08/2007 7:59:09 PM PDT by neverdem
MINNEAPOLIS, Aug. 8 Investigators have found what may be a design flaw in the bridge that collapsed here a week ago, in the steel parts that connect girders, raising safety concerns for other bridges around the country, federal officials said on Wednesday.
The Federal Highway Administration swiftly responded by urging all states to take extra care with how much weight they place on bridges of any design when sending construction crews to work on them. Crews were doing work on the deck of the Interstate 35W bridge here when it gave way, hurling rush-hour traffic into the Mississippi River and killing at least five people.
The National Transportation Safety Boards investigation is months from completion, and officials in Washington said they were still working to confirm the design flaw in the so-called gusset plates and what, if any, role they had in the collapse.
Still, in making public their suspicion about a flaw, the investigators were signaling they considered it a potentially crucial discovery and also a safety concern for other bridges. Gusset plates are used in the construction of many bridges, not just those with a similar design to the one here.
Given the questions being raised by the N.T.S.B., it is vital that states remain mindful of the extra weight construction projects place on bridges, Secretary of Transportation Mary E. Peters said in a statement issued late Wednesday.
Since the collapse, the concern among investigators has focused on fracture critical bridges, which can collapse if even a single part fails. But neither the safety board nor the federal Department of Transportation on Wednesday singled out any particular design of bridge in raising its new concerns about gusset plates and the weight of construction equipment.
Concerns about the plates emerged not from the waters of the Mississippi River...
(Excerpt) Read more at nytimes.com ...
Thaanks, I realized that after I went to bed. 100 tons of rocks is 2.5 trucks at the legal limit. That shouldn’t be too hard to carry on an 8-lane bridge.
Who knew??? /s
All you have to do is add the whole url with out any html and it automatically becomes a hyperlink.
Hmmmmm. I wonder if the bridge’s gusset plates were designed by the same engineering firm that was responsible for the tunnel supports in Boston’s Big Dig?
It was Kennedy and Nixon who continued the conspiracy started by Eisenhower. This was a secret plan to put flaws in numerous interstate bridges for future use. Rove's mind control machine made Bush decide this was the time to spring the plan. It will be found that important people directed a number of things the day of the collapse that took advantage of the design flaws. None of them were on the bridge when it fell. All of this will point to a number of Muslims on the work crew, all of whom "died" in the accident. This will be used to further inflame the country against Muslims and escalate the unjust war!
Oh, shoot. I thought this was DU. Sorry.
Knowing what I do about road construction, has anyone thought about the vibrating rollers used to flatten the asphalt? When they paved our street a couple of weeks ago, the one roller shook my entire house.
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Yeeeeeeeeah. That's what makes me nervous about crossing old steel bridges. I don't doubt the design. I doubt the maintenance program.
I wonder what the safe lifespan is for steel bridges, even when properly maintained. Each time the beams and rivets get sandblasted, they have to get smaller and weaker.
Steel in the absence of corrosion and in appropriate designs should last nearly forever.
I believe that I read that this bridge had an automatic corrosion de-icing system installed to help get through MN winters. Looking at the design of the bridge, all drainage looked to be directed towards the ends of the main span arch, which seems to be near where the initial failure(s) occurred.
This side of the bridge failed after the main span dropped and pulled on this part, likely causing it to jump up and leave its supports and crash to the ground.
Grand Island?
Bingo. Just have your ‘rat reps fix it for you. Start with H!.
“design flaw in the so-called gusset plates”
Why are the gusset plate “so-called” Is the NYT trying to imply the guesset plates aren’t gusset plates? Maybe that’s why the bridge fell down. Dick Cheney made Haliburton use a hot plate instead of a guesset plate so his stock would go up.
No asphalt on the bridge. It was cement.
good info
kstp.com/article/stories/s163284.shtml?cat=63
http://kstp.com/article/stories/s163284.shtml?cat=63
Why are the the two inside lanes (left side of picture) black?
Yes, sir!
Grand Island, NY. Where are you?
I lived near Clarence for a decade ~40 yr ago.
Maybe Rosie O’Dogface can explain what happened??
Pray for W and Our Troops
The author is in way over his head. There are no girders in this bridge. It is a truss.
The gussets also known as connections are certain to have failed. That has been known here since the first hour or so. The question is which of several possible modes led to the failure. Flaw is possible but not likely since the bridge has been operatopnal for a long time.
I referred in earlier posts to bolted connections. A freeper told us they were riveted. I didn’t think they were still using rivets in the 60’s but close ups of the bridge seems to show rivets rather than high strength bolts.
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