September 11

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Yeah, we're the pigs :rolleyes:

The conclusions are painfully obvious to me as well as NIST, who you seem to love mentioning but not actually quoting.

Your inability to comprehend that multiple factors rolled together to bring these towers down is startling. Your inability to understand that computer modelling can't possibly account for a million real life variables in an unprecedented collapse of these towers is pathetic. I hope you don't believe all the crap you've been fed by conspiracy websites. Of all the things to question surrounding 9/11, the actual collapse of the buildings is not even on the list.
 
Gixxer6 said:
Shaman, I do have a question for you though. If the buildings were brought down by explosives (highly time consuming and intrusive to install would likely have been noticed by the office worker or the like) or some other device planted by whomever you believe to have committed this heinous acts, why did they bother to put planes into the buildings why not just use more explosives?
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Plausible deniability. Everyone on the planes was/is dead at point of impact, and dead men tell no tales. Also doesn't trigger a massive manhunt with uncomfortable questions, since there's apparently nobody to apprehend.

But I didn't say that explosives brought down the buildings. I'm not going to theorize, just going to stick with what's known. I do think that there had to be more than just the planes involved...

See quotes I've already provided outlining that NIST did not ever physically model the collapse because they couldn't. All they modelled was the airplane impacts and supposedly the heat from the fire. I won't even go into how laughably bad some of their methods were at the moment... and I'm just now finding out that the NIST report has been repeatedly modified since the first release in 2005 when I had my major interest in the events. It seems I'm going to have to dig deeper than I have time for this evening.
 
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Shaman said:
What impressive debating tactic. You can't disprove what I'm saying, or even argue it... because I used qualified sources. Clearly, you haven't got a clue about any of this, or you'd at least try to raise an argument.

So instead, you attack my person.

Who's the idiot again?
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You are.

No, seriously. Take a breath and look in the mirror.
 
Another clueless brickbatter. This is fun.

OK, let's play the game YOUR way...

I know you are, but what am I?
 
If you're not prepared to learn something new, you shouldn't ask any questions. All I did was answer your question.
 
fastar1 said:
If you're not prepared to learn something new, you shouldn't ask any questions. All I did was answer your question.
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What I learned is that if what you say is true, I don't lack for company.
 
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Shaman said:
Plausible deniability. Everyone on the planes was/is dead at point of impact, and dead men tell no tales. Also doesn't trigger a massive manhunt with uncomfortable questions, since there's apparently nobody to apprehend.

But I didn't say that explosives brought down the buildings. I'm not going to theorize, just going to stick with what's known. I do think that there had to be more than just the planes involved....
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You seem to have misunderstood, my point is that the planes were unnecessary if the buildings were brought down by other means. If this is a government cover-up, does the cover story "terrorist's bomb WTC" not suffice?
 
Shaman said:
The twin towers were designed from the beginning to withstand two plane hits...
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Are you fking kidding me? What engineer at that time pre-9/11 thinks to himself before he designs the building that it would take 3 planes to bring the twin towers down let alone even fathom a plane hitting the building.

I don't know or read as much as you but having multiple floors crashing down just seems logical for the building to crumble as it did.
 
Shaman said:
I quoted the official report. I might agree with you that it isn't reliable... but that's what YOU are saying happened.



FEMA. FEMA and NIST said it. So did PM - they just pumped their data up to 1800 degrees to make the results fit their agenda, but the investigators - including PM's own - failed to show how that was possible. Watch their documentary.



I totally do not. It was designed to hold *twice* its static load. So if a top section dropped 12', there's a short term dynamic load, but does the whole building drop in seconds? Well, NIST physically modelled it and said no. It's in the official report, not just some conspiracy web site.

Do I really need to go through the NIST report to prove my point? Cuz if that's what you're saying, what's going to happen is that I'm going to have a decaf and hit the sack instead, if that's OK with you.



I seriously think you have reading comprehension problems. I continue to talk about the OFFICIAL REPORT, and how they say that they COULD NOT RECREATE THEIR HYPOTHESIS about how the towers fell, and did not believe it could have happened that way. I also quoted the lead engineer for the building. Then I quoted FEMA's report on the fire.

So who are you going to believe... me, or all the government engineers you think said it happened in a pancake collapse...... who actually said that that it didn't?
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You still haven't cited your sources properly. I am not sure why you can't or won't.

So for now its just you versus what a read on PM. If you are sure that the PM collapse test is on the net somewhere... why can't you cite it?

Sent from my HTC Desire using Tapatalk 2
 
Trust him guys, the engineers designed the building to withstand every conceivable airliner crash for the following 100 years. Also, there was no wind up there so the fire didn't burn hot.

:) amazing
 
Sorry for the novel….
Shaman doesn’t want to cite the NIST disaster study properly, so I guess I’ll take a stab at it and do it myself.
The study can be found here: http://www.nist.gov/el/disasterstudies/wtc/

I will include some key points, taken directly from that study, that are relevant to this discussion.

Here is a summary of their study on the collapse of WTC1 and WTC2. I don’t see any ambiguity or uncertainty in their findings as previously suggested.

  • In WTC 1, the fires weakened the core columns and caused the floors on the south side of the building to sag. The floors pulled the heated south perimeter columns inward, reducing their capacity to support the building above. Their neighboring columns quickly became overloaded as columns on the south wall buckled. The top section of the building tilted to the south and began its descent. The time from aircraft impact to collapse initiation was largely determined by how long it took for the fires to weaken the building core and to reach the south side of the building and weaken the perimeter columns and floors.
  • In WTC 2, the core was damaged severely at the southeast corner and was restrained by the east and south walls via the hat truss and the floors. The steady burning fires on the east side of the building caused the floors there to sag. The floors pulled the heated east perimeter columns inward, reducing their capacity to support the building above. Their neighboring columns quickly became overloaded as columns on the east wall buckled. The top section of the building tilted to the east and to the south and began its descent. The time from aircraft impact to collapse initiation was largely determined by the time for the fires to weaken the perimeter columns and floor assemblies on the east and the south sides of the building. WTC2 collapsed more quickly than WTC 1 because there was more aircraft damage to the building core, including one of the heavily loaded corner columns, and there were early and persistent fires on the east side of the building, where the aircraft had extensively dislodged insulation from the structural steel.

From the Dr. Sunder’s (lead investigator) presentation at a public briefing on April 5[SUP]th[/SUP] 2005, regarding the WTC towers being designed to withstand the impact of a Boeing 707.
Buildings are not specifically designed to withstand the impact of fuel-laden commercial airliners. While documents from The Port Authority of New York and New Jersey (PANYNJ) indicate that the impact of a Boeing 707 flying at 600 mph, possibly crashing into the 80thfloor, was analyzed during the design of the WTC towers in February/March 1964, the effect of the subsequent fires was not considered. Building codes do not require building designs to consider aircraft impact.

From the NIST’s FAQ section on this disaster study.
15. Has NIST responded to those who believe that the WTC towers and WTC 7 collapsed in ways other than the mechanisms determined by the NIST investigation?
NIST respects the right of others to hold opinions that do not agree with the findings and conclusions described in its reports on the collapses of WTC 1, 2 and 7. However, the WTC investigation team stands solidly behind these findings and conclusions, including the failure mechanisms defined for each building and the sequences of events leading to the initiation of the three collapses.

6. What caused the collapses of WTC 1 and WTC 2?
Based on its comprehensive investigation, NIST concluded that the WTC towers collapsed because: (1) the impact of the planes severed and damaged support columns, dislodged fireproofing insulation coating the steel floor trusses and steel columns, and widely dispersed jet fuel over multiple floors; and (2) the subsequent unusually large number of jet-fuel ignited multi-floor fires (which reached temperatures as high as 1,000 degrees Celsius, or 1,800 degrees Fahrenheit) significantly weakened the floors and columns with dislodged fireproofing to the point where floors sagged and pulled inward on the perimeter columns. This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers. Both photographic and video evidence—as well as accounts from the New York City Police Department aviation unit during a half-hour period prior to collapse—support this sequence for each tower.

8. Why didn’t NIST consider a “controlled demolition” hypothesis with matching computer modeling and explanation like it did for the “pancake theory” hypothesis?
NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.

Regarding the structure below impact being able to support the structure above impact after the collapse;
12. Was there enough gravitational energy present in the WTC towers to cause the collapse of the intact floors below the impact floors? Why weren’t the collapses of WTC 1 and WTC 2 arrested by the intact structure below the floors where columns first began to buckle?
Yes, there was more than enough gravitational load to cause the collapse of the floors below the level of collapse initiation in both WTC towers. The vertical capacity of the connections supporting an intact floor below the level of collapse was adequate to carry the load of 11 additional floors if the load was applied gradually and 6 additional floors if the load was applied suddenly (as was the case). Since the number of floors above the approximate floor of collapse initiation exceeded six in each WTC tower (12 floors in WTC 1 and 29 floors in WTC 2), the floors below the level of collapse initiation were unable to resist the suddenly applied gravitational load from the upper floors of the buildings.
Consider a typical floor immediately below the level of collapse initiation and conservatively assume that the floor is still supported on all columns (i.e., the columns below the intact floor did not buckle or peel off due to the failure of the columns above). Consider further the truss seat connections between the primary floor trusses and the exterior wall columns or core columns. The individual connection capacities ranged from 94,000 pounds to 395,000 pounds, with a total vertical load capacity for the connections on a typical floor of 29,000,000 pounds (see Section 5.2.4 of NIST NCSTAR 1-6C). The total floor area outside the core was approximately 31,000 square feet, and the average load on a floor under service conditions on Sept. 11, 2001, was 80 pounds per square foot. Thus, the total vertical load on a floor outside the core can be estimated by multiplying the floor area (31,000 square feet) by the gravitational load (80 pounds per square foot), which yields 2,500,000 pounds (this is a conservative load estimate since it ignores the weight contribution of the heavier mechanical floors at the top of each WTC tower). By dividing the total vertical connection capacity (29,000,000 pounds) of a floor by the total vertical load applied to the connections (2,500,000 pounds), the number of floors that can be supported by an intact floor is calculated to be a total of 12 floors or 11 additional floors.
This simplified and conservative analysis indicates that the floor connections could have carried only a maximum of about 11 additional floors if the load from these floors were applied statically. Even this number is (conservatively) high, since the load from above the collapsing floor is being applied suddenly. Since the dynamic amplification factor for a suddenly applied load is 2, an intact floor below the level of collapse initiation could not have supported more than six floors. Since the number of floors above the level where the collapse initiated exceeded six for both towers (12 for WTC 1 and 29 for WTC 2), neither tower could have arrested the progression of collapse once collapse initiated. In reality, the highest intact floor was about three (WTC 2) to six (WTC 1) floors below the level of collapse initiation. Thus, more than the 12 to 29 floors reported above actually loaded the intact floor suddenly.

Regarding melting steel;
15. Since the melting point of steel is about 1,500 degrees Celsius (2,800 degrees Fahrenheit) and the temperature of a jet fuel fire does not exceed 1,000 degrees Celsius (1,800 degrees Fahrenheit), 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.

Regarding the limited oxygen supply to the fires;
17. NIST states that the fires in WTC 1 were generally ventilation limited. If this was the case, wouldn’t the fires have burned out in about 2 minutes? Why do NIST’s models show the fires burning longer?
Nearly all fires are limited either by the burning rate of combustible fuel (fuel-limited fires) or by the availability of air (ventilation-limited fires). Many fires that are ventilation limited do continue to burn, with the burning rate determined by the chemistry of the combustion and the rate at which the oxygen arrives. This was generally the case for the WTC Tower fires. Of course, if the rate of air inflow were too slow (e.g., due to very few broken windows), the limited combustion would not have generated sufficient heat to continue pyrolyzing fuel, and the fire would have gone out. This was not the case on the fire floors in the WTC towers.
The FDS, used to reconstruct the fires in the WTC towers, included the burning characteristics of the building combustibles and the ventilation through the broken windows and the damaged building façade. The simulation showed that there were ample perforations in the building facade to maintain the ventilation-limited combustion until the fuel supply was depleted.

19. If thick black smoke is characteristic of an oxygen-starved, lower temperature, less intense fire, why was thick black smoke exiting the WTC towers when the fires inside were supposed to be extremely hot?
Nearly all indoor large fires, including those of the principal combustibles in the WTC towers, produce large quantities of optically thick, dark smoke. This is because, at the locations where the actual burning is taking place, the oxygen is severely depleted and the combustibles are not completely oxidized to colorless carbon dioxide and water.
The visible part of fire smoke consists of small soot particles whose formation is favored by the incomplete combustion associated with oxygen-depleted burning. Once formed, the soot from the tower fires was rapidly pushed away from the fires into less hot regions of the building or directly to broken windows and breaks in the building exterior. At these lower temperatures, the soot could no longer burn away. Thus, people saw the thick dark smoke characteristic of burning under oxygen-depleted conditions.

From the FAQ section regarding the collapse of WTC7:
4. What caused the fires in WTC 7?
Debris from the collapse of WTC 1, which was 370 feet to the south, ignited fires on at least 10 floors in the building at its south and west faces. However, only the fires on some of the lower floors—7 through 9 and 11 through 13—burned out of control. These lower-floor fires—which spread and grew because the water supply to the automatic sprinkler system for these floors had failed—were similar to building fires experienced in other tall buildings. The primary and backup water supply to the sprinkler systems for the lower floors relied on the city's water supply, whose lines were damaged by the collapse of WTC 1 and WTC 2. These uncontrolled lower-floor fires eventually spread to the northeast part of WTC 7, where the building's collapse began.
5. How did the fires cause WTC 7 to collapse?
The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.
According to the report's probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.
(See WTC7 FAQ section for diagram)
Diagram 1—Typical WTC 7 floor showing locations of columns (numbered). The buckling of Column 79 was the initiating event that led to the collapse of WTC 7. The buckling resulted from fire-induced damage to floors around column 79, failure of the girder between Columns 79 and 44, and cascading floor failures. (Credit: NIST)

The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.
The probable collapse sequence is described in NIST NCSTAR Report 1A, Section 2.4 and NIST NCSTAR Report 1-9, Chapter 13.

7. How did the collapse of WTC 7 differ from the collapses of WTC 1 and WTC 2?
WTC 7 was unlike the WTC towers in many respects. WTC 7 was a more typical tall building in the design of its structural system. It was not struck by an aircraft. The collapse of WTC 7 was caused by a single initiating event—the failure of a northeast building column brought on by fire-induced damage to the adjacent flooring system and connections—which stands in contrast to the WTC 1 and WTC 2 failures, which were brought on by multiple factors, including structural damage caused by the aircraft impact, extensive dislodgement of the sprayed fire-resistive materials or fireproofing in the impacted region, and a weakening of the steel structures created by the fires.
The fires in WTC 7 were quite different from the fires in the WTC towers. Since WTC 7 was not doused with thousands of gallons of jet fuel, large areas of any floor were not ignited simultaneously as they were in the WTC towers. Instead, separate fires in WTC 7 broke out on different floors, most notably on Floors 7 to 9 and 11 to 13. The WTC 7 fires were similar to building contents fires that have occurred in several tall buildings where the automatic sprinklers did not function or were not present.
8. Why did WTC 7 collapse, while no other known building in history has collapsed due to fires alone?
The collapse of WTC 7 is the first known instance of a tall building brought down primarily by uncontrolled fires. The fires in WTC 7 were similar to those that have occurred in several tall buildings where the automatic sprinklers did not function or were not present. These other buildings, including Philadelphia's One Meridian Plaza, a 38-story skyscraper that burned for 18 hours in 1991, did not collapse due to differences in the design of the structural system (see the answer to Question 9).
Factors contributing to WTC 7's collapse included: the thermal expansion of building elements such as floor beams and girders, which occurred at temperatures hundreds of degrees below those typically considered in current practice for fire-resistance ratings; significant magnification of thermal expansion effects due to the long-span floors in the building; connections between structural elements that were designed to resist the vertical forces of gravity, not the thermally induced horizontal or lateral loads; and an overall structural system not designed to prevent fire-induced progressive collapse.

13. Did investigators consider the possibility that an explosion caused or contributed to the collapse of WTC 7?
Yes, this possibility was investigated carefully. NIST concluded that blast events inside the building did not occur and found no evidence supporting the existence of a blast event.
In addition, no blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses. According to calculations by the investigation team, the smallest blast capable of failing the building's critical column would have resulted in a sound level of 130 decibels (dB) to 140 dB at a distance of at least half a mile, if unobstructed by surrounding buildings. This sound level is consistent with a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert.
For the building to have been prepared for intentional demolition, walls and/or column enclosures and fireproofing would have to be removed and replaced without being detected. Preparing a column includes steps such as cutting sections with torches, which produces noxious and odorous fumes. Intentional demolition usually requires applying explosive charges to most, if not all, interior columns, not just one or a limited set of columns in a building.
 
It is impossible for anything of structure to fall at the freefall speed of gravity. Period.
The only waythat can happen is if the structure is removed simultaneously. Impossible for the weakening of columns to all give way at the same time, especially considering that 90% of them weren't even subject to heat stresses at all. As one floor falls onto another, there would have to be a momentary pause before the next tier could yield.

For all three buildings to do so, and to find molten steel (that melts at nearly 3000 dgrees), supposedly caused by jet fuel (that burns at 800 degrees), and thermite microscopic powder substances all over the entire debris site, to me, points to something alot more destrucive than a plane wreck.
 
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omnivore said:
It is impossible for anything of structure to fall at the freefall speed of gravity. Period.
The only waythat can happen is if the structure is removed simultaneously. Impossible for the weakening of columns to all give way at the same time, especially considering that 90% of them weren't even subject to heat stresses at all. As one floor falls onto another, there would have to be a momentary pause before the next tier could yield.

For all three buildings to do so, and to find molten steel (that melts at nearly 3000 dgrees), supposedly caused by jet fuel (that burns at 800 degrees), and thermite substances all over the entire debris site, to me, points to something alot more destrucive than a plane wreck.
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All these points are addressed in the report I linked to. Go read it.

Sent from my HTC Desire using Tapatalk 2
 
This is great video noting the mental state of people who believe 9/11 was not done by the government: http://www.youtube.com/watch?v=_UtVeo0ylgg


As well anyone notice the LACK of any 9/11 specials last night? Don't you find it strange?
 
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omnivore said:
It is impossible for anything of structure to fall at the freefall speed of gravity. Period.
The only waythat can happen is if the structure is removed simultaneously. Impossible for the weakening of columns to all give way at the same time, especially considering that 90% of them weren't even subject to heat stresses at all. As one floor falls onto another, there would have to be a momentary pause before the next tier could yield.

For all three buildings to do so, and to find molten steel (that melts at nearly 3000 dgrees), supposedly caused by jet fuel (that burns at 800 degrees), and thermite substances all over the entire debris site, to me, points to something alot more destrucive than a plane wreck.
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They don't have to feel the heat stress. Once a few fail from heat, the rest can buckle and fail from overload.

That being said, I still don't think jet fuel would have provided enough heat to warm columns of that size especially concrete encased columns for the most part. Just isn't realistic to me. Also The fact that it was a completely self contained collaps just doesn't really do it for me. It's possible. There is some probability out there in the universe that it could happen. But not twice on the same day at two neighbouring buildings. Anyways thats my young civil engineer in training point of view. When I get my stamp in a few months I'll let you guys know if I change my mind :rolleyes:
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