WTC7 collapse, new numerical results

Great Debates
181

I’m not obsessing over the jet fuel.

My number one issue is that the buildings collapsed in a symmetrical fashion. I can accept that the supports in the area where the planes struck were severed and that the fires ultimately caused the collapse of supports in that area.

What I have trouble accepting is that the floors beneath the impact site suffered universal failures so great that it would allow a free fall compression of the entire building. Likewise the floors above the impact site were obliterated and did not retain their form in any manner either.

It is certainly possible, and even NIST’s model suggests, that as one side failed, it would cause the remaining supports to fail. One side would pull down the sides that were still intact. The inability to explain** a universal failure of the supports** is what keeps me skeptical.

Here’s a compilation of demolition fails. What these fails suggest is bringing down a building is much harder that one might imagine and that a symmetrical collapse is highly unlikely without planning.

182

What is your theory as to what happened that day?

183

For how long have you had trouble accepting this? I mean, a good chunk of the building above those floors (ie, the floors in the impact zone and above) did come down on them with a lot of momentum already.

184

[quote=“LAZombie, post:181, topic:840064”]

I’m not obsessing over the jet fuel.

My number one issue is that the buildings collapsed in a symmetrical fashion. I can accept that the supports in the area where the planes struck were severed and that the fires ultimately caused the collapse of supports in that area.

What I have trouble accepting is that the floors beneath the impact site suffered universal failures so great that it would allow a free fall compression of the entire building. Likewise the floors above the impact site were obliterated and did not retain their form in any manner either.

It is certainly possible, and even NIST’s model suggests, that as one side failed, it would cause the remaining supports to fail. One side would pull down the sides that were still intact. The inability to explain** a universal failure of the supports** is what keeps me skeptical.

Here’s a compilation of demolition fails. What these fails suggest is bringing down a building is much harder that one might imagine and that a symmetrical collapse is highly unlikely without planning.

[/QUOTE]

Taller buildings fall easier. I have touched upon why in several posts in this thread. None of the real demolition fails in your link are tall buildings, they are only a few floors. When the steel supports weakened, there were what, 20 floors resting on them? And not tiny, small square footage floors, huge ones. When a support fails, the load will instantly increase on the rest of them.

And as for the youtube video… come on. Even the comments are remarking on how fake some of those are. 0:55 could hardly look more fake if you tried, and some of the others are dubious-looking.

It seems to me like you are thinking the towers would topple sideays rather than fall. The problem is, the towers are heavy, and gravity pulls straight down. Nothing is pushing them sideways and you’d need a lot of force to make something that heavy move sideways. Nor are they going to pivot on the walls, walls don’t have that kind of material strength. They basically act like a liquid under that kind of stress.

Nothing is going to" retain their form" the forces involved here make sure of that.

185

What’s so symmetrical about a very large portion of 1 impacting 7?

What’s so symmetrical about a very large portion of 2 crossing the street to fall on a Greek Orthodox church?

What’s so symmetrical about nearly all of 7 crossing the street to fall on Fiterman Hall followed by the southwest corner of 7 separating and sliding into the Verizon building next door?

186

NOAA image of all the debris in situ

Notice all the debris at the foot of the Bankers Trust building and between the Merill Lynch & American Express buildings? Human remains were recovered from the American Express property and the parking lot on the other side of Vesey Street from the American Express property. How would any symmetrical collapse account for all of this?

187

Planes crashed, buildings collapsed – they were never designed to take that kind of stress.

188

Jet fuel is combustible. That’s why it’s fuel. However, it is not usually explosive.

189

[RIGHT][/RIGHT]

See JAQing Off.

190

I used to play with wooden blocks as a kid (well ok, my entire life). My towers always fell down in an almost symmetrical pattern.

I could get them to fall sideways a little bit with a bad foundation.

I could get the side to fall off if I had a low wall.

But my tall towers fell pretty much straight down when there was a structural failure fairly high up (which, as it happens, is what you get when you build with blocks)

191

No, I don’t think they would topple because they were especially well built. They were resilient. No one has made the accusation of shoddy work or faulty materials or flawed engineering. The weight of the buildings is a constant and its support system was handling the task of holding it up adequately.

The only additional forces the lower floors of the building endured were the weight of the plane and the impact of the upper floors collapsing onto the area damaged by the planes. That is a quantifiable amount of energy. Are you arguing that the collapse acted as a pile driver causing a complete symmetrical collapse?

While the force of the collapsing floors is great, it has to seen relative to the entire building and how that kinetic energy would distribute itself.

192

No it doesn’t. It only needs to be seen relative to the floor beneath it. If the floor beneath it can’t handle the load and it collapses along with the materials above it. If that one floor can’t handle the dynamic load and collapses, then repeat for the floor beneath it until, you either find a floor that can handle an ever increasing mass of material falling down on it, or until you’ve reached the bottom. The buildings didn’t collapse from the bottom, they collapsed from the points of impact down. Which also explains why they didn’t topple over like some of your completely different demolition fails. The lower floors of WTC 1 & 2 didn’t fail until the floors above them came crashing down on them with the aid of gravity.

So what do you think happened and for how long have you been of the belief that the official narrative was seriously flawed?

193

Well, as Northern Piper points out, there are people who do just that, but when they get rid of the planes, they sound even more crazy, so most truthers have to keep them.

As for the explosives, they have to keep those too, because the vast majority of Truthers became truthers because the collapses “didn’t look right”, and they’ve spent years (almost decades now!) finding “evidence” to support that original belief. For them to now admit that explosives are incredibly unlikely would require them to realize that their original impressions of the collapses were in error, and thus their entire belief structure is with a foundation.

And one thing every debunker has seen is that most Truthers are constitutionally incapable of admitting error, no matter how small. Hell, just take a look at that list LAZombie has been posting, and consider how many of the “factual” points in that list have been comprehensively shown to be wrong. And yet, he still posts it. They ALL still post it.

Okay, here is an absolutely critical question, that may very well address the fundamental error you’re making in trying to understand the collapse: in each instance where you refer to “the supports” above, which “supports” are you talking about? Be very, very specific, please.

194

It doesn’t matter if it was shoddily built or not. Its not a paper airplane. Its not going to go sideways unless it has a force pushing it sideways, and for something massing that much, it would need to be a very large force and distributed over a large area. Otherwise it’d just penetrate the structure without transferring enough energy. Like trying to push a cubic meter of jello with the point of a needle. Old disaster movies don’t actually give you a real impression of how structures this large behave.

Like ASL v2.0 points out the force does not distribute itself over the entire building, just the area it impacts. What ASL v2.0 is leaving out is that the you are not talking about just the force that cause the weakened iron to collapse plus the floor that just collapsed:

The mass is under acceleration!

For an extremely simplified calculation, the towers massed about half a million tons, so very roughly 5 000 tonnes plus contents per floor. When supports give and twentyish floors start to fall, those hundred, hundred and fifty thousand tons do not just put a hundred and odd thousand tons of weight to the next floor. They impact it at about 7.5 meters per second. That is a lot more force than just having the weight placed on you. It is the difference between supporting yourself on your legs as you stand, and dropping from ten feet to land on your feet.

Now that floor gives, so the one beneath it takes that weight plus ten-fifteen thousand tons more now traveling at 10 m/s. Ten floors on, the mass is traveling at 25 m/s. That is equal to the difference between jumping of a ten foot ledge and one a hundred foot off the ground.

Yes, you can quantify the force hitting the floor below (actually the area of the floor won’t significantly matter it doesn’t contribute enough to resistance, it’ll be the area of the walls and supports) and that force is very, very, large and scaling up rapidly for every floor it falls.

195

And, even then, much of the cores of both remained standing for a significant period of time.

196

How symmetrical is symmetrical?

In every film I have seen, the collapse begins with a slight tilt to one side or another.
The tilt ends to go away when the overall building begins to collapse.
Are you aware of the size of those buildings? Each had a footprint of approximately one acre. Are you aware of how much force is required to shift an acre of steel and concrete sideways?

I guess that if you used explosive to blow out a single wall, you might get it to lean over, but the fires weakening the girders and joists involved the entire floor–walls, paint, furniture, office supplies, carpeting, decorative features, etc. (That is what the fuel ignited; no reputable source has claimed that the fuel burned long enough to torch the supports.)

So with an acre of burning objects, even if one support failed first, (no argument against that), all the supports had been under stress long enough so that the failure of one portion cause the immediate failure of nearby supports.

197

[quote=“LAZombie, post:181, topic:840064”]

I’m not obsessing over the jet fuel.

My number one issue is that the buildings collapsed in a symmetrical fashion. I can accept that the supports in the area where the planes struck were severed and that the fires ultimately caused the collapse of supports in that area.

What I have trouble accepting is that the floors beneath the impact site suffered universal failures so great that it would allow a free fall compression of the entire building. Likewise the floors above the impact site were obliterated and did not retain their form in any manner either.

It is certainly possible, and even NIST’s model suggests, that as one side failed, it would cause the remaining supports to fail. One side would pull down the sides that were still intact. The inability to explain** a universal failure of the supports** is what keeps me skeptical.

Here’s a compilation of demolition fails. What these fails suggest is bringing down a building is much harder that one might imagine and that a symmetrical collapse is highly unlikely without planning.

[/QUOTE]

You obviously do not understand the structural design of the WTC towers and how they differed from other constructions. The steel supports formed the perimeter of the building allowing for unobstructed floor space in the interior.
This tube-framed design contained most of the collapse to the centre.

198

For those who are interested, Ryan Mackey wrote On Debunking 9/11 Debunking: Examining Dr. David Ray Griffin’s Latest Criticism of the NIST World Trade Center Investigation which covers a lot of the conspiratard bullshit being posted by LAZombie, and why it’s all bullshit. Worth a read.

Here’s the link. [pdf warning]

199

“We looked at every possible thing we could think of that could happen to the buildings, even to the extent of an airplane hitting the side,” Skilling told the Seattle Times. “However, back in those days people didn’t think about terrorists very much.”
Concerned because of a case where an airplane hit the Empire State Building, the designers did an analysis that showed the towers would withstand the impact of a Boeing 707. On Sept. 11, 2001, terrorists hit the Twin Towers with two larger Boing 767’s.
“Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed,” he told the Seattle Times. **“The building structure would still be there.”
** My bolding.

200

Obviously, the idiot is wrong.