Grand Island is in the middle of the Niagara River just a few miles from Niagara Falls.
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 Board’s 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 ...
So you recognized the bridges... : )
They were in much better shape back then.
I have been battling the thruway authority and the corrupt government here for years and continue to do so now.
This is the stock pile of articles I have been keeping on my battle.
http://albanysinsanity.wnymedia.net/?cat=26
Please post some information on the corrosive properties of this de-icing system.
You can google as well as I.
Money quote: "He went on to say that the same chemicals used in the automatic de-icing process are used when the solution is put down manually."
Check the b4 pictures of the bridge and note the rust at the bottom joints near the piers.
As the frogs were saying in 1967 (and are still saying for truck frames today), ribbet.
From the manufacturers website,
Cryotech CF7® offers these advantages: Low Corrosion -- Contains no chlorides
High Performance -- Effective to -26°C (-15°F) and below
Safe for the Environment -- Non-persistent and biodegradable
Dual Purpose -- For prewetting solids or direct application
Safe to Use -- Low toxicity to humans and aquatic organisms
Easy to Handle -- A clear liquid, no agitation required
Lasts Longer -- Requires fewer applications
The MnDOT report said that the bridge de-icer didn’t reduce the salt dumped on the bridge. So since the de-icer does have some corrosive properties, it adds to the corrosion.
The MnDOT report said that the bridge de-icer didn’t reduce the salt dumped on the bridge. So since the de-icer does have some corrosive properties, it adds to the corrosion.
Its a long report, so I missed the part where it said the system didn't reduce the salt dumped on the bridge. Please point that out to me.
If the solution used by the de-ing system is less corrosive than salt, its application would have washed away the more corrosive salt. The net result would be less corrosion.
SOP is to fix two lanes at a time, while leaving two live lanes.
Once the first two are complete, they are opened to traffic, and work begins on the other two.
The center lanes aren't getting any traffic.
Were they putting down a concrete overlay or had they ground the deck down prior?
They had ground down the deck and had dumped 100 tons of gravel on the bridge preparing for the cement pour.
I noticed the same light weight construction in the photos.
I also think the design of the truss looks weird. At the four supported points the truss relies on just one vertical post of the type you describe; I would have expected that three members would be joined at the “foot” to spread the load (the vertical and two opposing diagonals). The false arc seems to do nothing but weaken the design while increasing the center span height a little.
I haven't ever seen overlay that dark with stripes. I saw another picture that the dark pavement seemed to be thicker than the active traffic surface.
Must be a different video from the one that I studied -- frame-by-frame -- using diffferential transparency mode to reveal minute changes in position. According to that video, the collapse took a full quarter-minute, with the deck collapse over the south main piers occurring only after the main span was completely in the water and the "splash wave" had subsided.
If you have a URL, please share it with me. I'd love to study the video you saw -- thanks!
Where is the South Grand Island?
Grand Island is in the middle of the Niagara River just a few miles from Niagara Falls.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.