PROOF that Building 7 was demolished with explosives!!!

reply to post by pteridine


They collapsed about as close you can get to free fall speed. For instance, here is the ever faithful NIST on WTC 7:

"Stage 1 (0 to 1.75 seconds): acceleration less than that of gravity (i.e., slower than free fall).
Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (free fall)
Stage 3 (4.0 to 5.4 seconds): decreased acceleration, again less than that of gravity."

And then we get NIST again, you haven't been doing your reading, tisk tisk tisk. Here's an excerpt from the whole:

"the building section above came down essentially in free fall" And now the whole:

"How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based on: (1) precise timing of the initiation of collapse from video evidence, and (2) ground motion (seismic) signals recorded at Palisades, N.Y., that also were precisely time-calibrated for wave transmission times from lower Manhattan (see NCSTAR 1-5A).

As documented in Section 6.14.4 of NIST NCSTAR 1, these collapse times show that:

“… the structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.”

In other words, the momentum (which equals mass times velocity) of the 12 to 28 stories (WTC 1 and WTC 2, respectively) falling on the supporting structure below (which was designed to support only the static weight of the floors above and not any dynamic effects due to the downward momentum) so greatly exceeded the strength capacity of the structure below that it (the structure below) was unable to stop or even to slow the falling mass. The downward momentum felt by each successive lower floor was even larger due to the increasing mass.

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely."

Yours,

THE AQUARIAN 1

reply to post by THE AQUARIAN 1


The conclusion is that they did not collapse at freefall speed.

What exactly does "essentially in free fall" mean then?

And, just to let you know, board rules restrict you from making one sentence posts.

What of this? Of course from NIST:

"Since the melting point of steel is about 2,700 degrees Fahrenheit, the temperature of jet fuel fires does not exceed 1,800 degrees Fahrenheit and Underwriters Laboratories (UL) certified the steel in the WTC towers to 2,000 degrees Fahrenheit for six hours, how could fires have impacted the steel enough to bring down the WTC towers?

In no instance did NIST report that steel in the WTC towers melted due to the fires. The melting point of steel is about 1,500 degrees Celsius (2,800 degrees Fahrenheit). Normal building fires and hydrocarbon (e.g., jet fuel) fires generate temperatures up to about 1,100 degrees Celsius (2,000 degrees Fahrenheit). NIST reported maximum upper layer air temperatures of about 1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers (for example, see NCSTAR 1, Figure 6-36).

However, when bare steel reaches temperatures of 1,000 degrees Celsius, it softens and its strength reduces to roughly 10 percent of its room temperature value. Steel that is unprotected (e.g., if the fireproofing is dislodged) can reach the air temperature within the time period that the fires burned within the towers. Thus, yielding and buckling of the steel members (floor trusses, beams, and both core and exterior columns) with missing fireproofing were expected under the fire intensity and duration determined by NIST for the WTC towers.

UL did not certify any steel as suggested. In fact, in U.S. practice, steel is not certified at all; rather structural assemblies are tested for their fire resistance rating in accordance with a standard procedure such as ASTM E 119 (see NCSTAR 1-6B). That the steel was “certified ... to 2000 degrees Fahrenheit for six hours” is simply not true."

Now this has to do with a one Kevin Ryan who wrote in 2004 for the UL, to Frank Gayle deputy chief of the Metallurgy Division at the National Institute of Standards and Technology (NIST):

"We know that the steel components were certified to ASTM E119. The time temperature curves for this standard require the samples to be exposed to temperatures around 2000F for several hours. And as we all agree, the steel applied met those specifications. Additionally, I think we can all agree that even un-fireproofed steel will not melt until reaching red-hot temperatures of nearly 3000F (2). Why Dr. Brown would imply that 2000F would melt the high-grade steel used in those buildings makes no sense at all."

Also from Kevin Ryan are as follows:

"Additionally this summary states that the perimeter columns softened, yet your findings make clear that "most perimeter panels (157 of 160) saw no temperature above 250C". To soften steel for the purposes of forging, normally temperatures need to be above 1100C (6)."

In case you were wondering who Kevin Ryan is:

"Kevin Ryan is the former Site Manager for Environmental Health Laboratories, a division of Underwriters Laboratories (UL). Mr. Ryan, a Chemist and laboratory manager, was fired by UL in 2004 for publicly questioning the report being drafted by the National Institute of Standards and Technology (NIST) on their World Trade Center investigation."

And, in case you are unaware of the UL:

en.wikipedia.org...

Pretty much the foremost test facility in the world.

Yours,

THE AQUARIAN 1

And what of this:

www.opednews.com...

"We also know that UL consulted directly with the Port Authority’s WTC construction team, on fire resistance issues, as the towers were being built. This was described in the May 2003 NIST progress report that shows that the towers were built specifically to UL standards for fire resistance."
wtc.nist.gov...


"UL's own Tom Chapin, the chemist and manager of their Fire Protection division, with whom I was in contact, admitted to UL's involvement in testing steel (i.e. that which allowed the towers to stand) for the WTC by writing -- "The World Trade Center stood for almost an hour after withstanding conditions well beyond those experienced in any typical fire. In that time, thousands of people escaped with their lives. ASTM E-119 and UL's testing procedures helped make that possible."
J. Thomas Chapin, General Mgr., Fire Protection Div. Underwriters Laboratories, Letter to the editor entitled “Fire Test is Sound”, New York Times, April 15, 2002.

reply to post by GenRadek


"More can be found that will confirm what I and the fire fighter chief said. Steel BEGINS to lose strength at around 300C."

Ummm, did you forget to read the article from the Fire Fighter Chief that you posted on this forum, or do you just skim my posts:

"If you reduce the structure’s mass you can build cheaper and builder higher. Unfortunately unprotected steel warps, melts, sags and collapses when heated to normal fire temperatures about 1100 to 1200 degrees F."

If you missed it, the fire chief said that steel warps, MELTS, sags and COLLAPSES at 1100 to 1200 degrees.

So, I mean, yeah, Steel BEGINS to lose strength when you heat it above room temperature. It is a fact that it doesn't MELT or COLLAPSE at 1100 degrees.

Go lay down.

Yours,

THE AQUARIAN 1

Let's assume the steel re enforced core of the building reached a high enough temperature to collapse. Which is did not.

Lets assume that the steel wasn't welded together which would act as a heat sink drawing the heat away from the hot areas. When in fact they were welded together and it would take a much higher temperature than that required to weaken the steel if it were isolated.

Lets assume the fire was still raging even though a few people were signaling for help from the holes in the building, indicating the fires were almost out. Which wasn't the case.

The building would not collapse in its own foot print. It would fall over in the direction of the weakened area. Following the laws of physics . Following the path of least resistance. Not fall through itself and the strength of solid steel.

Show me one other steel re enforced building that has collapsed that way throughout history?

No architect will agree with this pan cake theory.

video.google.com...#

reply to post by THE AQUARIAN 1


He is correct. You are misreading and misinterpreting what HE is saying. What he is saying is that the steel will warp, bend and such when heated to normal fire temperatures about 1100 to 1200 degrees F. So what he is saying is that steel will fail at normal fire temps. And the big deal is what exactly? Reading comprehension comes into play here.

If it is true that steel begins to lose its strength at 300C, then it means it will begin to deform at temps found at the higher, regular fire temperatures of 1100F. (pay close attention to the Celsius and Fahrenheit ). That is when the steel will noticeably lose its strength and begin to fail. Again what does BEGINS mean? It BEGINS to lose its strength. So using something called logic and critical thinking, at higher temps, it will lose more and more of its strength, to the point where failure is expected, especially if there are heavy loads and stresses applied to the steel. I thought you would have understood that part. So again the chief is right, you are wrong. He was merely mentioning the higher temp when visible deformation will take place.

When the steel is sufficiently weakened by fire, failure can occur when the beam or the connections give way. For someone who types a lot, you really are missing the main picture here. NIST is correct about their conclusions, the fire chief is also correct on his conclusions. The only one making an non-issue an issue is you.


[edit on 2/18/2010 by GenRadek]

Originally posted by Doctor Smith
Let's assume the steel re enforced core of the building reached a high enough temperature to collapse. Which is did not.

Lets assume that the steel wasn't welded together which would act as a heat sink drawing the heat away from the hot areas. When in fact they were welded together and it would take a much higher temperature than that required to weaken the steel if it were isolated.

Lets assume the fire was still raging even though a few people were signaling for help from the holes in the building, indicating the fires were almost out. Which wasn't the case.

The building would not collapse in its own foot print. It would fall over in the direction of the weakened area. Following the laws of physics . Following the path of least resistance. Not fall through itself and the strength of solid steel.

Show me one other steel re enforced building that has collapsed that way throughout history?

No architect will agree with this pan cake theory.

video.google.com...#

The Twin Towers' floors were not welded. There were no I-beams holding up the floors. They were trusses. Light steel trusses that were bolted at the ends, connecting to the columns. The core columns were not welded either. Some of the exterior columns were welded at the transfer floors, but the rest of them were not welded either. They were all bolted.

reply to post by Doctor Smith

Show me one other steel re enforced building that has collapsed that way throughout history?

Society of Fire Protection Engineers made a study of building collapses
from fire. Looked at 22 cases through 2002 including WTC complex

6 were steel frame buildings. Of the 6 studied steel frame buildings 4
were at the WTC complex (WTC 1,2,5,7) which collapsed.

www.fpemag.com...

A total of 22 such cases were identified through 2002 after extensive searches of the literature, news, and other contacts, with the Sept. 11 disasters in New York and Washington, DC, counting as five of these incidents [World Trade Center (WTC) 1, 2, 5, and 7, and the Pentagon].

The NIST survey of 22 fire-induced building collapses from 1970-2002 identified a variety of conditions, materials, locations, and buildings. Fifteen cases were from the U.S., two from Canada, and five from Europe, Russia, and South America. The numbers of fire collapse events can be categorized by building material as follows:

Concrete: 7 (1 in Pentagon 9-11 event)
Structural steel: 6 (4 in 9-11 WTC events)
Brick/Masonry: 5
Wood: 2
Unknown: 2

So the people who design fire protection systems realize the potenial for collapse from fire.

The pre-collapse photographic analysis showed that 16 recovered exterior panels were exposed to fire prior to collapse of WTC 1. None of the nine recovered panels from within the fire floors of WTC 2 were observed to have been directly exposed.

NIST developed a method to characterize maximum temperatures experienced by steel members using observations of paint cracking due to thermal expansion. The method can only probe the temperature reached; it cannot distinguish between pre- and post-collapse exposure. More than 170 areas were examined on the perimeter column panels ...

Only three locations had evidence that the steel reached temperatures above 250 °C.

These areas were:

• WTC 1, east face, floor 98, column 210, inner web,
• WTC 1, east face, floor 92, column 236, inner web,
• WTC 1, north face, floor 98, column 143, floor truss connector

Other forensic evidence indicates that the last example probably occurred in the debris pile after collapse. Annealing studies on recovered steels established the set of time and temperature conditions necessary to alter the steel microstructure. Based on the pre-collapse photographic evidence, the microstructures of steels known to have been exposed to fire were characterized. These microstructures show no evidence of exposure to temperatures above 600 °C for any significant time.

Similar results, i.e., limited exposure if any above 250 °C, were found for two core columns from the fire-affected floors of the towers.

www.911blogger.com...

No temps got high enough to cause failure of thousands of tons of steel in any of the buildings.

No steel was recovered and tested from WTC7, but it's obvious from known physics and precedence that fire doesn't cause global collapse.
They're lying about the towers and obviously WTC7, why did they not do more testing?

reply to post by thedman


Yeah and out of those tested how many collapsed globally?

3 of them, WTC1, 2 and 7...

reply to post by GenRadek


Not welded huh?









Then what are they doing? You just make things up mate.

[edit on 2/18/2010 by ANOK]

I have watched video time after time and see no foul play whatsoever. Dont get me wrong I think the whole event was suspicious, especially the Pentagon, but this is maybe just a building falling. What you think is explosions on different floors may be just windows and cement structures giving way, it has to start falling somewhere, they blow out and it happens to other windows around the building as supports continue to fail.

I directed my friend and his father to this video, his dad is an explosives engineer they do anything from fireworks nights to structutal demoliotion here in th UK and testing armour on army vehicles etc, using explosives.

I did not tell them what the vid was or anything just showed them and asked them to give me thoughts. The response was the building has collapsed due to structural weakness. I asked if it was due to explosives. Their response, "no, unless a child installed them". They added after I explained why I asked them to watch it "the detonation of explosives leaves a taletail signature, this does not have it"

They positively insisted that they had no bad feeling about it and had no doubt it was not due to explosives.

Also, I think its a little extreme for the OP on a site designed for people to have freedom of thoughts and opinions to turn around and say "your all nuts if you dont believe this, you must all be living in magical la la I believe the government land". This site promotes debate, not suppresion. Sort your attitude out. I do not understand why users comments like that either removed, or the user is warned about the purpose of this site.

I am undecided still, I do not know if this was or was not foul play, I am 50/50, what insult will you throw at me for that OP?

Either way, insult me or not thanks for posting the video, I found it interesting and that is also a part of this sites strategy. An interesting read.

reply to post by ANOK


Would you be so kind as to show were you got those photos from? What source exactly. Cause that does not look like the WTC 1 or 2 Towers under construction or the original WTC7. Also three of those photos dont even show welding!

Especially this one:
Where are the welders mask? Also this looks like it is the location of WTC5, not WTC 1 or 2 or 7. Nice try at making things up. Caught you!

I see no explosions and nothing to to support your theory. All I see are windows blowing out as the building shifts, some electrical flashes as breakers and transformers are popped, but NONE of the flashes you get from demo explosions.

And yes, I think the whole 9/11 conspiracy is a bunch of dung, but am always open to having my mind changed which is why I'm here.

Originally posted by GenRadek

Originally posted by Doctor Smith
Let's assume the steel re enforced core of the building reached a high enough temperature to collapse. Which is did not.

Lets assume that the steel wasn't welded together which would act as a heat sink drawing the heat away from the hot areas. When in fact they were welded together and it would take a much higher temperature than that required to weaken the steel if it were isolated.

...

The Twin Towers' floors were not welded. There were no I-beams holding up the floors. They were trusses. Light steel trusses that were bolted at the ends, connecting to the columns. The core columns were not welded either. Some of the exterior columns were welded at the transfer floors, but the rest of them were not welded either. They were all bolted.

Unbelievable how some people have no idea how things are done. Of course buildings are welded and of course they had a much more complex and strong structure than your ridiculous false statements!

Here is a professional French study that took a look at the weld's of the towers:

Scientific Analysis of Twin Towers Welds

Here is an excellent website that fully analyzes the twin towers, their construction, and their demolition, including a discussion about the welding that was done, including photographs:

World Trade Center Demolition

Also, here is a case study made by MIT to study how these high-rise buildings are to be made so that they DON'T fall down. This information was readily available all over the Internet prior to 9/11, but all information on how these buildings ARE in fact built has mysteriously been wiped from the Internet since that time. Who has the ability to wipe the Internet clean of information on how high-rise buildings are truly made?

60 STATE STREET - A Case Study

Please deny ignorance, as that is what this site is all about...


[edit on 18-2-2010 by downisreallyup]

reply to post by GenRadek


Looking at that image - one other note, the guy isn't welding, he is grinding. That's a grinding gun in his hand.

Plus you see those cables that are strung between the columns - that's a level of fall protection that was not required when the WTC towers were built.

I didn't see anything that would indicate explosives. I served in the Army for 24 years and used quite a lot of explosives and I didn'tsee any indication of explosives being used in that clip.

I do not think the 9/11 attacks were some sort of "Flase Flag" thing. I suggest you young men go enlist in the Army or marines and fight the bastards who attacked us instead of ranting about this. I am getting the impression that you do not have the guts to defend your country. You need some excuse to stay home.

reply to post by GenRadek


My bad I was in a hurry I posted the wrong pics...

'Composite floors comprise 900mm deep bar joists (spaced at 2.04 m centres and braced transversely by secondary joists) and a 10 cm thick lightweight concrete slab laid on steel trough decking as permanent formwork. Composite action between the concrete and the steelwork is ensured by extending the diagonal web members of the joists through the steel decking and embedding them in the slab. Dead weight of floor 50 kg/in2, imposed load 488 kg/in2.'

'Each upper floor comprises 32 prefabricated units spanning between core and external columns. These units are of two sizes: 18.3 x 6.0 m along the longitudinal faces of the core and 10.7 x 4.0 m along the transverse faces. Additional beams are provided to strengthen the four corner bays.'

It is not clear exactly what the phrase "each upper floor" means in this instance. It turns out that 18 floors have heavy steel beams instead of trusses. Consider the following quote from Engineering News-Record, January 1, 1970.

'On the 41st and 42nd floors, both towers will house mechanical equipment. To accommodate the heavy loads, the floors are designed as structural steel frame slabs. All other floors from the ninth to the top (except for 75 and 76, which will also carry mechanical equipment) have typical truss floor joists and steel decking.'

'Typical office floors have 4-in. thick slabs of composite construction using top chord knuckles of the joists (trusses), which extend into the slab, as shear connectors. On mechanical floors, composite action is provided by welded stud shear connectors...'

...Composite flooring is the name given to floors where studs (called shear studs or shear connectors) are welded to the supporting joists/trusses and then concrete is poured around them, setting them solidly in the concrete slab. The joist-concrete composite slab is significantly stronger than a non-composite slab. In the case of the WTC the main double trusses used their top knuckles as shear connectors. Ordinary shear studs were used along the transverse trusses. We have the following quote from Godfrey:'

www.debunk911myths.org...

...Intact and aircraft impact damaged welds from the exterior columns of the World Trade Center towers were evaluated. The fillet welds joining the various steel plates composing the built-up box columns were primarily deposited using submerged arc welding.

files.aws.org...

Analysis of the steel to be conducted in both Gaithersburg and Boulder will be done to determine properties and quality of the metal, welds and connections, and to provide data for other investigation projects. This portion of the research will include:

(why test the welds if there aren't any?)
wtc.nist.gov...

But to say nothing was welded is ridiculous.

[edit on 2/18/2010 by ANOK]