Posted on 08/01/2007 4:28:27 PM PDT by ButThreeLeftsDo
Just turned on the news. 35W bridge collapsed in the Mississippi River. Cars, trucks, semis.....
Fires burning, tanker trucks, at least one school bus, more than ten cars......
Just now breaking.......
LOL. It's like changing from harassment to "hairessmant".
that the Minnesota NICE!!!
Well....
There's a big dollop of crossed-logic at play here.
IF, "they" are telling the truth when they keep repeating that this bridge had multiple single-point-of-failure components, any one of which would bring the whole shebang crashing down, then it obviates the need for an army of trained experts with multiple precisely positioned charges.
All it would take would be ONE small cutter charge, which any dumf*k nose-picker could put in place after being shown a couple of photos and being told "allah be with you, now get going."
Personally, after seeing all the aerial footage of the wreckage, and the Army Corps of Engineers surveilance tape, I think it quite likely that there were indeed multiple charges, not necessarily timed all that accurately (but in this day and age it wouldn't take more than a few bucks to buy pretty accurate timers at any department store). Probably one per segment, at one of the many "single point" components.
And, as with 911, the effect may very well have been more than they bargained for. Remember that captured videotape of OBL with his scumbag buddies yukking it up over how the destruction at the WTC was much greater than they'd ever hoped for?
IMO the word has come down that the story is to be given a certain spin. I've watched reporters putting words into the mouths of interviewees, then thanking them for confirming the "facts" (which they never even said!) and ending the interview. That kind of crap doesn't happen for no reason. The only question is where the "push" came from. Did the reporter have it in his mind that it was "a tragic accident", and therefore he was going to make his interviewees sound like they confirmed it, or, did his bosses tell him to spin it that way, or, did his bosses get told to spin it that way?
For better or worse (my money is on the latter), we are in the age of "managed" news. It was not long after 911 that the feds sat down the media bigwigs and they worked out protocols for how to manage the delivery of any future terrorist attacks.
At the time, that struck me as a major assault on the First Amendment. And frankly I've seen nothing to persuade me to the contrary since then.
There is a palpable surreality to hearing in one ear that we are to be ever vigilant, to brace for attacks, and to worry about certain things (i.e., bridges) being likely targets -- and, in the other ear, to always hear -- within minuts of any event -- that there is no idea as to what caused it, but don't worry, there is NO indication of terrorism. I mean, please, are we THAT stupid?
Maybe.
PS: There is also the matter raised in Post # 1,867
{The above is a reply, at the bottom of the page in the URL. Easier to pull it up that way than by loading the entire page.)
Last night an eyewitness reported that a sheriff’s car was blocking a hole that appeared to have been drilled into the concrete of one of the lanes and his buddy commented that “this looks suspicious” prior to the disaster.
Hopes dim for families of missing
http://www.twincities.com/news/ci_6531081
—
NTSB head: Bridge shifted 50 feet as it collapsed
http://www.twincities.com/allheadlines/ci_6537627?source=rv
I saw on the local news that the water there was about 11 feet, then they were going to drain some using the dam to 9 feet.
Incidentally, I can't believe the bottom chord that you marked would be under tension. That would imply its function was to pull downward on the upper end, which would make little sense in this sort of bridge.
Here’s another one for you from my friend, and neighbor, a total Swede, in response to “hairessmant”—
Uff Da!
(Note: This is not a phrase uttered in my home. I have to draw the line.)
In my opinion, it is extremely important immediately to get an INDEPENDENT explosives team to the area. Have them determine if explosives were used.
If they truly are independent, then their report will prevent a lot of conspiracy theorizing in the future.
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Then he brought in FR 'awstats' Edition ^.
If you want to secure your own system get a copy of G-Zapper ^. It cleans/prevents Google et el tracking. It put the following in my 'hosts' file under the systems 'Window' folder:
# Begin GZapper
0.0.0.0 www.google-analytics.com
# End GZapper
That just consigns any reference for that site to the bit-bucket. I'm sure there's others out there like GZ. Bottom line is don't rely on others to secure your system from all the script-kiddies and their corporate devils.
" their report will prevent a lot of conspiracy theorizing in the future."
That's not likely.
Get an independent explosives team in now or forever suffer the conspiracy theorists. That’s just the way it is. If I were governor of Mn, it would be on my top ten list of things to do.
Conspiracy theorists are not in charge and shouldn't be. That's a good thing. They are simply paranoids. They key there is that suspicion is irrationally founded and reality simply can not be grasped. They see everthing as being arbitrarily caused by some etherial evil force and they're only comfortable with others that agree with them. It's bizzzare. The govm't doesn't need to get any more bizarre than it already is. Wasting tax money on bizarre is evil.
Besides, in the pic I posted showing where the failure occurred there's already a dozen guys there standing around. Those are feds. They're giving orders on what materials need to be disposed of and destroyed and what evidence needs to be planted. Those cops there are there to make sure no one gets close enough to see the real evidence, before it's taken away.
Oh no! You've given away the secret. </sarcasm>
He he he !!!
It's a simple vector relationship. If it’s an eqilateral triangle, and the king post is taken out, a downward load of 1/2*(the load) is applied to each lateral side. The compressive stress in each side beam is 0.707*load. The sides oppose that force and transfer it to the base by existing under compression. At the base, 0.707*load is applied at each end vertex.
Resolving that into it's components shows the resulting stresses perpendicular and parallel to the base. One component of the force points downward and perpendicular to the base. At each vertex, that component is 1/2*load, for a total downward force of the total load applied. The other component points away from the vertex, parrallel to the base, in a direction away from the other vertex in the base chord. The magnitude of that component is 1/2*load at each vertex. That's a tensile load of magnitude 1/2*load in the base chord.
If you want a "sense" regarding the force in the base do the following experiment in your head. Balance 2 sticks on the table top, so that they look like a triangle. Note the length of an imaginary base stick you'd need to make a complete triangle. Then push down on the top vertex. Now, what happened to the imaginary base stick? Was it crushed, or stretched?
I’m still having trouble with this.
A member in tension tends to elongate. Easy to see in the bottom chord of a flat truss. The bottom chord elongates as the truss deflects.
I don’t see how an arched bottom chord can be in tension. If it elongates, the truss sags UPWARD.
I’m not arguing with you, I’m trying to clarify, because if this is true, it is decidely counter-intuitive.
LOL...BTW, thanks for the explanations in your other posts on the cause of collapse. Interesting stuff.
Prez just gave some remarks after getting a close-up look at the site. He talked one-on-one with a man who was on the bridge and who helped get some of the kids off the bus. They stood, just the two of them, right next to the part of the bridge where the bus is.
If the bottom chord in that arched truss is stretched, the top must contract under compression. It will not bow up, it will bow down.
Look at any king post, real or imaginary, in one of the trangular elements near the center. When the arch is stretched it will staighten out. The king post in the center will pull the center of the top chord down.
Now look at the king post at an end. Stretch the bottom chord and the king post will rise up, moving the vertex of the triangle up.
The thought experiment can be done by compressing the bottom chord. The top chord will bow upwards in that case.
Shapes can always be approximated by decomposing them in to triangles. In the arched truss, they just get smaller, then larger along the long axis of the truss. Finite element analysis often uses triangles, as "finite" elements, instead of points to model complex shapes and situations.
Thanks.
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