How it Was Done: 9/11 and the Science of Building Demolition

[Btodd]

The official story says a few fires made the entire structure soft like clay

 

[ManFromUncle]

http://heiwaco.tripod.com/blgb.pdf

You posted the paper by Bazant. Unfortunately when the stakes are so high we are going to have to think for ourselves rather than rely on an authority who posts a bunch of equations we don't understand. Here is just one refutation of Bazant, published in the same journal, there are others: http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/D25%20WTC%20Discussions%20Replies.pdf

A brief summary of major points for layman is here at 911research.net:

The paper repeatedly claims to make the most optimistic assumptions about building survival with no discussion of what that means. It contains nonsensical engineering claims such as:



[... if the] majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed.


There are two major fallacies in this assertion:

• It implies that the columns were capable of supporting only twice the gravity loads they were bearing above the impact zone. This ignores the fact that the upper floors, lacking standing-room-only crowds, were not carrying their design live loads, and it implies that reserve strength ratios (the extra strength designed into a structure beyond what is required to resist anticipated loads) are two-to-one instead of the five-to-one typical in engineered steel structures.

• It implies that a failure of the columns to support the gravity loads above the impact zones would automatically lead to total collapse, despite the absence of a single example of a local collapse event leading to total collapse in any steel-framed building.

If you don't think the stakes are high follow the trail of dead witnesses such as Barry Jennings, chief of emergency response in NYC, who was the last man out of WTC7 and said there were many explosions in the building which were definitely not boilers going but "explosions." Jennings said in an interview:

I am just confused about one thing and one thing only - why World Trade Center 7 went down in the first place. I am very confused about that. I know what I heard - I heard explosions. The explanation I got was it was the fuel oil tank. I am an old boiler guy

A credible NYC official sticking to "explosions" is a real problem. What would explosives be doing in the building?

Jennings died a few days before a major NIST report on WTC7 was released, at the age of 53, causes still unknown and the whereabouts of his family still unknown, who suddenly moved.

[youtube]PbbZE7c3a8Q[/youtube]

Barry Jennings Mystery



The point here is you have to understand the basic science for yourself, for a crime of this magnitude obviously there will be an enormous cover-up operation in place.

Dead 9/11 witnesses: 9/11: The Dead Witnesses - 911 Truth Archive

 

[Edial]

When a falling mass meets resistance energy is absorbed, not created. ...

I think you might be restating what some other folks are saying without really looking into it.

When a falling mass (solid mass) meets resistance only some of the energy is absorbed.
If the heavy solid mass is falling down with certain speed and a debris (from explosion or compression) bounces up unto it, the falling mass would certainly absorb some of the impact, but it will also increase the bounce back speed ... unless of course the falling mass is as soft as sand.

Take a tennis paddle and bounce the tennis ball off the floor few times.
Each time you hit the ball as it comes up, the speed of the tennis ball increases at the point of impact of the paddle as it hits downwards.

Thanks,
Ed

 

[Edial]

...

The point here is you have to understand the basic science for yourself, for a crime of this magnitude obviously there will be an enormous cover-up operation in place.
...

Dear ManfromUncle.

I am not saying 911 is a clear cut event ... it is full of holes. My goodness, does anybody really believe they actually found the passports of the hijackers on the ground. :o ... and then some of them are actually alive in Saudi Arabia?
Columbo (remember the old TV series? ) would be on it like glue.

Life is complicated.

All I'm saying is that we cannot accuse specific individuals or governments or agencies ... because we have VERY LITTLE information available to us.

Cover up?
Of course. Can you name me one event when you heard the whole truth and nothing but the truth on TV?

Whatever websites you quote would NEVER print the whole truth.
If the conspiracy is that huge, they would not be allowed to do so.

So let's work with the information we have and see what we see and do some "Columbo" work. ... the forums, right.

I assure you, you and I are not going to save the world.

Thanks,
Ed

 

[Btodd]

My goodness, does anybody really believe they actually found the passports of the hijackers on the ground. :o ... and then some of them are actually alive in Saudi Arabia?

Wait, what? That's an old Truther urban legend.


Btodd

 

[Edial]

Wait, what? That's an old Truther urban legend.


Btodd

No, I don't think so.

Too many articles from other sources support that ... just bumped into this in a quick search ...
BBC NEWS | Middle East | Hijack 'suspects' alive and well

 

[Edial]

I'm sure there were a lot of things smouldering, a plane just hit the building.

Have you ever seen a house fire? It can be a raging inferno, and there's black smoke pouring out of everywhere that the fire isn't as intense. It's not like we'd expect to see a raging inferno at the core, and a complete lack of smaller, less intense / smouldering fires surrounding the more intense area. We would expect to see smaller fires and smouldering areas all over the place, but that doesn't mean an intense fire is not present.

Yes, intense pockets of fire were definitely there.
I recall seeing flames coming off one side of the building (1 or 2) out of several windows.
This is an office fire fueled by jet fuel.

When house burns there are many metallic leftover items, like forks, even watches (glass is melted but the casing is there).

We are talking about really thick steel beams.

You're still ignoring the fact the fuselage went rocketing deep into the building taking out multiple floors along the way. That by any definition is a massive hole.

But look at the size of the hole on the building itself. The wings damaged mostly the outside of the building.
Beams were knocked off and there is a hole several human heights.

In comparison to the rest of the building the hole itself is not large at all.

Ok, so there's a specific point where someone was standing that didn't happen to be on fire. I still fail to see your point.

The point is, the fact that this poor redheaded lady who was standing at the whole waving to get attention (really, really sad), also showed there were no flames there.

The point is the most of the fires should be at (or around) the point of impact.

The fact that there weren't fires in that area, really raises questions whether or not airplane induced fires melted the steel.

Thanks,
Ed

 

[Btodd]

No, I don't think so.

Too many articles from other sources support that ... just bumped into this in a quick search ...
BBC NEWS | Middle East | Hijack 'suspects' alive and well

Don't fall prey to the 'too many articles, therefore it has credibility' stuff. ManFromUncle has repeatedly said that the Twin Towers fell at free fall speed, which is a claim you'll find in a ton of Truther sites...but it's not true, either.

The confusion over 'hijackers still alive' has a lot to do with commonality of Islamic names and mistaken identity. After all, what sense does it make to go to all the trouble of pulling off this grand conspiracy, and be dumb enough to use the names of Saudis who are still living and can blow the lid off the whole plan by saying, 'Hey, I'm still alive...here I am!'???

Most of the Truth Movement abandoned the 'hijackers are still alive' nonsense years ago, but it still resurfaces occasionally. To address your article:

"The problem, however, is that the FBI was "referring" to several people named "Waleed al-Shehri," and it was clear from the very beginning that there was more than one person with that name that the FBI was interested in, if only to narrow the list down to the one who did 9/11. A press release dated September 14, 2001 (available here: http://www.fbi.gov/pressrel/pressrel01/091401hj.htm) shows that the FBI was tracking up to�three men possibly named "Waleed al Shehri," one from Hollywood, one from Orlando and one from Daytona Beach:

"2) Waleed M. Alshehri - Dates of birth used: September 13, 1974/January 1, 1976/ March 3, 1976/ July 8, 1977/ December 20, 1978/ May 11, 1979/ November 5, 1979; Possible residence (s) : Hollywood, Florida/ Orlando, Florida/ Daytona Beach, Florida; Believed to be a pilot."​

As it turned out, the Waleed M. Alshehri who sat in seat 2B on American Airlines Flight 11--the one who was born in 'Asir Province, Saudi Arabia on December 20, 1978--had not trained at a flight school in the United States."

http://conspiracies.skepticproject.com/articles/911/hijackers-still-alive/


Btodd

 

[Paul01]

You posted the paper by Bazant. Unfortunately when the stakes are so high we are going to have to think for ourselves rather than rely on an authority who posts a bunch of equations we don't understand. Here is just one refutation of Bazant, published in the same journal, there are others: http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/D25 WTC Discussions Replies.pdf
...

This critique has some valid points, but is also speculative. Any valid engineering analysis will have a conservative enough approach in terms of assumptions and methodolgy so as to account for relatively minor errors that might accumulate along the way. It was formally critiqued as any scientific paper should be. It echoes the same conclusions, primarily that a controlled demolition was not necessary for collapse.

 

[Edial]

Don't fall prey to the 'too many articles, therefore it has credibility' stuff. ManFromUncle has repeatedly said that the Twin Towers fell at free fall speed, which is a claim you'll find in a ton of Truther sites...but it's not true, either.

The confusion over 'hijackers still alive' has a lot to do with commonality of Islamic names and mistaken identity. After all, what sense does it make to go to all the trouble of pulling off this grand conspiracy, and be dumb enough to use the names of Saudis who are still living and can blow the lid off the whole plan by saying, 'Hey, I'm still alive...here I am!'???

Most of the Truth Movement abandoned the 'hijackers are still alive' nonsense years ago, but it still resurfaces occasionally. To address your article:

"The problem, however, is that the FBI was "referring" to several people named "Waleed al-Shehri," and it was clear from the very beginning that there was more than one person with that name that the FBI was interested in, if only to narrow the list down to the one who did 9/11. A press release dated September 14, 2001 (available here: http://www.fbi.gov/pressrel/pressrel01/091401hj.htm) shows that the FBI was tracking up to�three men possibly named "Waleed al Shehri," one from Hollywood, one from Orlando and one from Daytona Beach:

"2) Waleed M. Alshehri - Dates of birth used: September 13, 1974/January 1, 1976/ March 3, 1976/ July 8, 1977/ December 20, 1978/ May 11, 1979/ November 5, 1979; Possible residence (s) : Hollywood, Florida/ Orlando, Florida/ Daytona Beach, Florida; Believed to be a pilot."​

As it turned out, the Waleed M. Alshehri who sat in seat 2B on American Airlines Flight 11--the one who was born in 'Asir Province, Saudi Arabia on December 20, 1978--had not trained at a flight school in the United States."

Hijackers Still Alive - 9/11 Conspiracies - Skeptic Project


Btodd

Just because someone is a "truther" as you call them does not mean everything they say is untrue. With this logic we can take any group and discount anything that group says, true or false, just because it came from that group.

I never looked at that claim deeper than a quick scan.
But I will.

Concerning the claim of finding the passports, this I found hard to believe.
I would have (and I have for years ), but so many other holes began to surface (some hoaxes and some true), the whole thing became one big question mark.

Concerning claims of having no hijackers at all.
We know planes hit the buildings.
Even the photos of the dent and damage are clear, wings and all.

Some were saying there were no planes at WTC at all.
They had a pretty good presentation that you cannot believe everything you see on TV and I myself remember clear as bell on Sept 11 2001 when I saw on Fox News the nose of the plane coming out the other side of the building.
I even commented to my co-workers "Wow, look at that, the impact was so strong the nose came out the other side" ...
I guess when you are in shock you do not realize what you are saying ... then I was like (years later) ... what the :o

Thanks,
Ed

 

[Aijalon]

I really like this step by step video of a do it yourself-er figuring out how easy it is to cut through steel and demonstrates how they were imploded.

9/11 Thermite - YouTube

 

[Aijalon]

Why are all the YouTube videos I play on this site washed out and so white I cannot see them?

 

[ManFromUncle]

I really like this step by step video of a do it yourself-er figuring out how easy it is to cut through steel and demonstrates how they were imploded.

9/11 Thermite - YouTube

What's funny is that in its "debunk" of 9/11 truth, Popular Mechanics said that thermite had never been used in a demolition. But it has. On the Chicago Sky Ride in 1935. It was reported in Popular Mechanics.

 

[Trogdor the Burninator]

Oh - thermite again.

Just remember, thermite and demolition charges, both oh which can apparently bring down a building on their own - are used interchangeably in 9/11 truther stories depending on what blurry photo they happen to have.

The WTC was like a Boss level in an 80s videogame - you needed two planes, thermite AND demo charges to beat it.

 

[ManFromUncle]

Oh - thermite again.

Just remember, thermite and demolition charges, both oh which can apparently bring down a building on their own - are used interchangeably in 9/11 truther stories depending on what blurry photo they happen to have.

The WTC was like a Boss level in an 80s videogame - you needed two planes, thermite AND demo charges to beat it.

What blurry photo are you talking about? I have never once referred to a blurry photo.

And what is so confusing about using a combination of methods for a large and complex demolition in which there is no room for error? It's not a tough concept, even for the layman who just understands what thermite and regular demolition charges are. Thermite would attack the strong points and start eating them away before final countdown, standard linear shaped charges (described in the post) would finish the job.

The thermite actually helps explain the puzzles of why people were jumping even after the fires were burned out, as the firefighters were reporting. 5,000 degree heat coming from the core would be intolerable.

9-11 Research: Firefighter Audiotape

 

[Btodd]

And what is so confusing about using a combination of methods for a large and complex demolition in which there is no room for error? It's not a tough concept, even for the layman who just understands what thermite and regular demolition charges are. Thermite would attack the strong points and start eating them away before final countdown, standard linear shaped charges (described in the post) would finish the job.

In a controlled demolition, before cutter charges are set, torches are used to 'pre-cut' the beams. This is where the cutter charge is placed, and serves to sever the rest of the beam when it goes off.

So what is the thermite for? To carry out what the torch already does, except that you now need tons and tons of thermite, some delivery system that also overcomes the challenge of getting thermite to go sideways through a vertical beam, and for...WHAT? So you increase your chances of failure, or getting caught...for WHAT?

On top of that, the collapses in the Twin Towers occurred from the points of impact. They were a top-down collapse, with no chain of charges going off prior to collapse.

THIS is what those charges sound like. We've already established that the idea of using thermite to do what is normally done by a torch during set-up is absurd and unnecessary, but to top it off...suddenly, we are supposed to believe that multiple charges, capable of severing these beams (and according to YOU, violently snapping and ejecting beams at 80+ mph, a much greater force than any standard demolitions charge)...were really, really quiet, too.

Yeah, makes tons of sense.

Here's what a demolition looks and sounds like...exactly what DIDN'T happen on 9/11.

https://www.youtube.com/watch?v=8U4erFzhC-U



Btodd

 

[tulc]

at this point the truther movement has become a religion and any fact that doesn't support the belief system is considered wrong or is disinformation being spread by some shadowy conspiracy group.
tulc(is aware of a certain amount of irony in this post)

 

[ManFromUncle]

In a controlled demolition, before cutter charges are set, torches are used to 'pre-cut' the beams. This is where the cutter charge is placed, and serves to sever the rest of the beam when it goes off.

So what is the thermite for? To carry out what the torch already does, except that you now need tons and tons of thermite, some delivery system that also overcomes the challenge of getting thermite to go sideways through a vertical beam, and for...WHAT? So you increase your chances of failure, or getting caught...for WHAT?

There are many different ways to skin a cat and demolitions are no different. We don't know the exact types of cutter charges that were used, if they were used. The post is merely a plausible hypothesis which fits the evidence much better than "magic kerosene" which is all jet fuel is:

Jet fuel - Wikipedia, the free encyclopedia

Here's what a demolition looks and sounds like...exactly what DIDN'T happen on 9/11.


Btodd

I love how you guys argue, first say there were "no explosions" like you hear in demolitions, then when confronted with explosions you say "those were rivets popping."

Explosions as tower is blown apart:
[youtube]uxB7R-z6E1I[/youtube]

 

[Trogdor the Burninator]

There are many different ways to skin a cat and demolitions are no different. We don't know the exact types of cutter charges that were used, if they were used. The post is merely a plausible hypothesis which fits the evidence much better than "magic kerosene" which is all jet fuel is:

The same magic jet fuel which brought down steel structures on a freeway in the US a few years later. I notice truthers are careful to avoid that one.

I love how you guys argue, first say there were "no explosions" like you hear in demolitions, then when confronted with explosions you say "those were rivets popping."

No - that would be truthers arguing "it was demo charges" whenever a noise or puff of smoke is seen, and "it was thermite" whenever it wasn't.

And yet - still not a single piece of evidence for a single suspicious person planting either one.

 

[Btodd]

There are many different ways to skin a cat and demolitions are no different. We don't know the exact types of cutter charges that were used, if they were used. The post is merely a plausible hypothesis which fits the evidence much better than "magic kerosene" which is all jet fuel is

You don't know what type of cutter charges were used, if they were used? What's the quote below?

Thermite would attack the strong points and start eating them away before final countdown, standard linear shaped charges (described in the post) would finish the job.

And you didn't address the issue, on top of that. As you said, you think thermite was used to get started on the strong points, eating them away before final countdown, when standard linear shaped charges would finish the job.

Which begs several questions:

1. When they were about to set up the standard linear shaped charges (which no one ever saw them do or found evidence of), why did they opt for using tons upon tons of thermite and an extensive delivery system instead that runs the risk of failing, not being timed properly, leaving tons of evidence, etc...instead of just using the torch like usual? If explosions are gonna go off anyway, then thermite isn't doing anything the torch didn't.

2. Where were the sounds of these standard linear shaped charges? At some point, you claim that beams were severed by the force of the blow, because you say it was powerful enough to eject them at 80+ mph. Quietly? The force you're talking about when you say that is much greater than a standard linear shaped charge, so the problem is even worse.

3. Where is any evidence of a sequence of explosions going off prior to the collapses? Pick any of the three buildings and tell me at what points you're hearing this sequence. It never happens. On one hand, they were standard linear shaped charges. On another hand, they were way more powerful than that. On the other hand, they were also really quiet and visually indistinguishable.

I love how you guys argue, first say there were "no explosions" like you hear in demolitions, then when confronted with explosions you say "those were rivets popping."

I love when you misrepresent what we argue in order to try to score some lame rhetorical point. The context of 'no explosions' has been explained to you, and I addressed it above. The 'explosions' you're talking about are demolitions charges, and if that were true...they would have been deafeningly loud. Point them out while we watch video just prior to, and during any collapse you wish. The only sound occurring in the video you posted is of a collapsing building (it's already doing what the charges would be needed for), there is no sequence of explosions even remotely like demolitions charges going off prior to collapse (from the impact points downward, no less).

You want to have your cake and eat it, too.


Btodd