Audio of the explosives which brought down WTC 7

[William Gaatjes]

Last bit first. WTC7 did sustain damage to (mainly) a corner. That no doubt weakened that corner and if it was substantial enough would cause the building to collapse in that direction. NIST indicated and I'd agree that that damage did not materially affect the building structurally nor the manner in which it collapsed. NIST informs us that fires alone caused the collapse of the building by causing the beam from column 44 (I think) to column 79 to 'walk' off etc. At one time NIST said the connections were bolted and at another time that they were not... I'm not sure today the reality of the connections nor have I seen the actual working drawings of that building... the drawings where changes are made to the original drawings to reflect the actual construction. It is normal to design a building and create drawings of that design only to have the actual construction change but with approval... the working drawing changes are then updated on the 'master' and that is then stamped etc... and archived.

RE: WTC 1,2.

For quite some time the structure held up the floors above even when a rather large bomb exploded in the garage of one of them. Pretty sturdy buildings they were..
Now then. Confining my comments to the WTC building that had the 15 floors above the impact zone I'll give you my take on how the physics of this issue played out.
Working from recall I think the gravitational energy available of the 15 floors was 2gjoules. I think my grandson worked that out pretty close to actual expected. The 15 floors are not a solid bit of titanium but, rather reinforced (#5 bar) and mesh cement flooring, steel beams and columns, office stuff and etc. The distance between the floor above and the structure below is the maximum distance the 15 floor 'block' could fall before impact. We can see all the stuff expelled from the structure as it begins its decent. That stuff flying out takes energy to accomplish and deducts from the total available. So it goes smash into the floor below and and equal and opposite force is exerted on the upper bit... so that what was destroyed below rendered the same destruction to the floor above. Key, however, to this meeting of the floors are two factors... one is that acceleration ought to have been slowed quite some bit. The other is that the core did exist and consider that it did hold the bit above for quite a time and should not have simply disappeared into 32' bits. The structure as one would expect was more massive the further down one went until the lower 1/3 was comprised of columns capable of holding up the entire structure above which now is not there. Only bits and pieces of stuff continued down through that path of greatest resistance as indicated in the footprint stuff pile. Of 110 stories of building only a pile of about 3 stories found themselves at the base and with in the foot print. All the rest of that building found themselves all over Manhattan or embedded in other structures.. so what energy source enabled the complete collapse? Worst possible case scenario indicates to me that the event had to stop above the 78th floor... there simply did not exist enough energy to crush anything into micro sized particulates and nice neat 32' sections of structural steel.
IF as you say they pancaked down... where are the pancakes? They are not in the footprint at the base. AND if they pancaked down why did they not leave the central core columns simply standing as they had since the building was finished? What crushed them down... not fire cuz there was none below and not the core columns above because if they did weaken due to what ever feature may have weakened them and if they were connected all the way down they'd opt to bend over rather than try to proceed through their once mated core below.
Even if all this did happen due to gravitational energy alone each meeting of each floor would dis enable acceleration to occur as a constant. The event should not have only taken 15 seconds (if it did take that long) It should have taken at least 70 seconds...
Look at that video... all that stuff falling to the side of the structure does not provide energy to the stuff falling through the path of greatest resistance... it diminishes energy by virtue of being tossed out. It is a sink... and energy sink.

Anyhow, the above in condensed form is the basic issue I have with the collapse of the towers... that and the molten stuff in the basements and the fire fighter's comments about 'explosions'... maybe there were and maybe there were not... but if not then I can't see that building collapsing as it did.

You mentioned that according to NIST there was structural failure.
Could it have been the case that visco elastic dampeners where used in WTC 7 as well ? These devices are a synthetic rubber sandwiched between steel plates. I would think that is something to consider. Because the rubber it seems cannot withstand heat. Before the extraordinary case of being rigged with explosives in a few hours, i myself would more likely search in a direction where maybe the design plans had some errors, or the materials where not up to par. Combine that with the debri that came crashing in. Possible explosion of the power station. Maybe the fuelpipes from the fueltanks where hit by debri leaking. I think a combination of probable possibilities is far more plausible then rigged with explosives.

In these kind of cases, the more complex, the higher the probability.
When it comes to prior knowledge... That is another situation.

 

[JTsyo]

A few questions for my detractors:

1. What do you believe the sequence of booms which caused people four blocks away to snap their heads in the direction of the building just prior to it coming down was?
2. What do you attribute the iron-rich microspheres and underacted flakes of nano-thermite found in the dust to?
3. How do you explain the inability of either the official investigations or anyone else to provide experimental confirmation to support the notion of fire-induced free fall?

As to your first question I believe the cause was probably cracks in the structure. These can be pretty loud. Just search youtube for videos of crack tests in labs.

I have no clue about the second one.

If the supports at the ground floor is compromised then, the remaining building would fall under freefall conditions. It's been awhile since I've seen the video so I don't remember how it fell.

 

[Sclamoz]

I figure this is less of a waste of time than contacting Barnett.

The reason you won't contact Dr. Barnett or another expert is you need to keep your fantasy going. Hey, here's an idea, why not find an expert on nano-thermite and contact them about your BS idea lol? Speaking of which, why aren't these people coming out in droves to support this idea if a handful of wackjobs can determine thermite was used to bring down the WTC?

Are you asking about papers on the subject of 9/11? That relates back to the above quote, as the woman who ran the peer-reviewed journal which published the nano-thermite paper was ran out of her job for doing so, and of course many others have met simlar fates for exposing the cover-up. On the other hand, this crap gets published and defended as if it were gospel, even though the first diargram is enough to expose it as nonsense to anyone who paid attention in middle school physical science class:

No, I was asking how many members of Architects and Engineers for 9/11 truth have published papers. I wonder how many of them even work in areas that would give them special insight into 9/11.

Further, Your article on thermite wasn't peer reviewed and the editor wasn't run out, she quit out of shame that such a hack article was published. Her own quote:

“I cannot accept that this topic is published in my journal. The article has nothing to do with physical chemistry or chemical physics, and I could well believe that there is a political viewpoint behind its publication. If anyone had asked me, I would say that the article should never have been published in this journal. Period.”

A thorough debunking of the nano-thermite dust idiocy was done years ago.

http://11-settembre.blogspot.com/2009/04/active-thermitic-material-claimed-in.html

It's funny you'll swallow any crazy ideas truthers come up but dismiss the 9/11 official reports out of hand based on BS papers and crazy internet videos.

 

[First]

Sure Bazant breaks out a bunch of integrals and such to make his argument look impressive, but all it takes is a remedial understanding of Newtonian physics and a clear head to know nobody could ever rightly hope to produce any semblance of experimental confirmation to support such crackpottery. Unfortunately, it seems most of our population lacks at least one of the two, and ingore if not lash out at the rest of us who do have both.

Except you don't know have a basic understanding of Newtonian physics, let alone how integrals work. We have already covered your lack of formal education and understanding of mathematics and physics in this thread already: http://forums.anandtech.com/showthread.php?t=329108&highlight=wtc7. No point in rehashing something you don't have any serious understanding of, so let's not pretend you can break down physics questions to their constituent components let alone adequately review an already peer-reviewed paper, rofl.

 

[LunarRay]

That was a day of firsts. They were patrolling the sky when they heard about another possible threat aircraft, so they took off.

I want mathematical proof that I couldn't possibly be right, otherwise I am.

Kyle, I am waiting for your answer, otherwise your argument is defeated.

The aircraft in question can probably do over 1600 knots. They may even have hit after burner and split in search of other 'targets'. Only problem is that no one has claimed to have heard that and there can be no doubt that it would have been quite loud enough to have been heard by anyone in the cone of sound developed by the aircraft.

 

[LunarRay]

I'm guessing you're talking about the 13 witnesses gathered by the two guys that call themselves Citizens Investigation Team, eh?

It's certainly pushing it based on Boeing's saftey specs, but I've seen no proof that it's impossible.

They may have seemed 'shady' but the two uniformed officers who drew the flight path on the photo of the area seem credible to me. They could not have seen the plane's approach [which implies that a plane did hit the pentagon] from their perspective as they explained it.
The damage to the front or entry point from one picture is still absent the expected damage extending out the dimension of the wings/engines.

The aircraft altitude and the density of the air are my major concerns in that situation. Any movement of the yoke would put the aircraft into the earth or well over the building but yet it flew almost a perfect vector to the target at 20' or so... had to hit them poles and all... that itself is not recorded in the FDR.... it should have been seen... the sensors are in the leading edge of the wing... which is what had to hit the light poles..

I am not saying it didn't happen but, rather, that if it did all the evidence should be in sync [I'll allow for eye witness - direct evidence - to be somewhat out of sync] but not the circumstancial stuff like the FDR etc.

 

[LunarRay]

You mean standing like this?



Total collapse, including the remaining core "spire" was over 30 seconds. The resistive force of the first floor to come into contact with the accelerating "upper block" will be negligible as it's many many times overloaded once this occurs. It does cause a momentary, barely noticeable slowing in the acceleration of the "upper block." Note that this does not mean at all that the upper block is slowing down, it is simply accelerating slightly slower for a moment, but accelerating it still is. The remaining mass of the first impacted floor is added to the mass of the upper block, which then impacts the floor below, rinse repeat. As the momentum of the upper block increases, each floor is able to provide an even smaller amount of the already negligible resistance the first impacted floor was able to, and is simply overwhelmed by the momentum of the upper block. The energy sinks due to ejection and the like are negligible.

Yup! I saw that video and that is actually what put the core column bug in my head... there are what... 3 columns standing there and the core section contained how many massive columns? Why did the three or so fall or collapse in any case? The foundation must have given out at that point, I guess.
You seem to suggest that that upper 'bit' or 'block' remained pristine throughout the event. It could not have... not and still comply with Newton's equal and opposite. The 15 floors above impact zone were gone into the atmosphere and flung to the side and elsewhere.. something made up all that stuff we see falling. I suggest it was the destruction of the upper bit and subsequent floors.

How about trying this... Find a definite point on the building that you can see before collapse and determine the floor level and when that point no longer contains building in the video.. use an adjacent building, for instance, as a marker... then as the event commences time how long it takes from start to that point... consider that that point is obscured by 'dust' after the point is past but it isn't too long. I think you'll find a reasonable time to go from top to the point selected and you'll know the distance traveled and the time it took... I don't think it matters much if you even select only say 50 floors... My timing indicated about 60% of FF acceleration.. but, I'm not a physics teacher so...

 

[LunarRay]

You mentioned that according to NIST there was structural failure.
Could it have been the case that visco elastic dampeners where used in WTC 7 as well ? These devices are a synthetic rubber sandwiched between steel plates. I would think that is something to consider. Because the rubber it seems cannot withstand heat. Before the extraordinary case of being rigged with explosives in a few hours, i myself would more likely search in a direction where maybe the design plans had some errors, or the materials where not up to par. Combine that with the debri that came crashing in. Possible explosion of the power station. Maybe the fuelpipes from the fueltanks where hit by debri leaking. I think a combination of probable possibilities is far more plausible then rigged with explosives.

In these kind of cases, the more complex, the higher the probability.
When it comes to prior knowledge... That is another situation.

I sorta give deference to the NIST team on many issues because they used 'outside' contractors as the engineering expertise. They may have set thresholds too high or low but that can be picked apart easily and has been in some cases.
Not having the actual construction drawings or the updated masters, I don't know what is where or of what configuration.
I will say this, however... It is quite plausible the building did collapse as NIST indicated - not as their model showed which did not mirror the actual video collapse - but it would not have been symmetrical as we see nor would the 2.25 second FF event have occurred. I know there was a bulge cuz my sister told me that... and that is structural disaster and should have caused the building to favor collapse in that direction.
I have no idea how or even why explosives could have been placed in WTC7. Nor do I think it absolutely necessary to have explosives to provide collapse if ALL other things were at play that could destroy that building.
I don't care what anyone says.... at about 4:30 that afternoon that building was an inferno. (again from my sister and my cousin who was a cop at the site at that time) But, I must say... an inferno with low temprature... about say 1100F because of the color of smoke and the fire you can see.

 

[kylebisme]

As to your first question I believe the cause was probably cracks in the structure.

Please watch the videos linked in the OP, as your argument makes no sense in the context of the evidence, and you can refresh your memory as to how WTC 7 came down. Also, your response to my third question didn't rightly address it, so I ask; while many claim free fall makes sense in the context of the official story, how do you figure it is that neither NIST nor anyone else has been able to provide any semblance of experimental confirmation to support that claim?

They may have seemed 'shady' but the two uniformed officers who drew the flight path on the photo of the area seem credible to me.

Did you see these comments from one of those officers which was linked in the previous link on the matter I gave you? I'm not suggesting the witness were lying, only that they were quoted selectively, and that they might have been manipulated into confusing what happened too. This video presents a humorous take on the matter.

The damage to the front or entry point from one picture is still absent the expected damage extending out the dimension of the wings/engines.

Can you mark on the picture what you are referring to specifically?

Any movement of the yoke would put the aircraft into the earth or well over the building but yet it flew almost a perfect vector to the target at 20' or so...

Yeah, I figure all the planes were most likely flown by computer, as UA 175's final approach was also quite a feat.

 

[event8horizon]

i always liked what Sunder had to say about freefall. i guess sunder didnt know (at this point in time) that wtc 7 fell for a couple of seconds at freefall!!

During the first round of questions in the Aug 26, 2008 NIST Technical Briefing (at 1:01:45 into the presentation) the following question was asked by David Chandler:

"Any number of competent measurements using a variety of methods indicate the northwest corner of WTC 7 fell with an acceleration within a few percent of the acceleration of gravity. Yet your report contradicts this, claiming 40% slower than freefall based on a single data point. How can such a public, visible, easily measurable quantity be set aside?"

Dr. Shyam Sunder replies:

"Could you repeat the question?"

[the question is repeated by the moderator, leaving out the word, "competent" as well as the last sentence]

"Well...um...the...first of all gravity...um...gravity is the loading function that applies to the structure...um...at...um...applies....to every body...every...uh...on...all bodies on...ah...on...um... this particular...on this planet not just...um...uh...in ground zero...um...the...uh...the analysis shows a difference in time between a free fall time, a free fall time would be an object that has no...uh... structural components below it. And if you look at the analysis of the video it shows that the time it takes for the...17...uh...for the roof line of the video to collapse down the 17 floors that you can actually see in the video below which you can't see anything in the video is about...uh... 3.9 seconds. What the analysis shows...and...uh...the structural analysis shows, the collapse analysis shows that same time that it took for the structural model to come down from the roof line all the way for those 17 floors to disappear is...um... 5.4 seconds. It's...uh..., about one point...uh...five seconds or roughly 40% more time for that free fall to happen. And that is not at all unusual because there was structural resistance that was provided in this particular case. And you had...you had a sequence of structural failures that had to take place and everything was not instantaneous."
--------

 

[LunarRay]

Can you mark on the picture what you are referring to specifically?

If I can get this link posted... down a bit is the photo that I've been looking at... the one that shows the missing damage... or to my eye it does. I guess it is the third photo down and the few following.


http://911review.org/Wget/investigate911.batcave.net/pentagon1.html

 

[LunarRay]

Yeah, I figure all the planes were most likely flown by computer, as UA 175's final approach was also quite a feat.

All of them flown by computer? Well... if they did find some of the alleged terrorists alive post 9/11 as BBC broadcasted... that might answer that. But then I'm left with another ... How did someone manage that enterprise? I know it can be done but wow... someone took out the pilots... and crew, I think... or do you suggest they never had pilots but did have passengers or neither?

 

[LunarRay]

i always liked what Sunder had to say about freefall. i guess sunder didnt know (at this point in time) that wtc 7 fell for a couple of seconds at freefall!!

--------

I actually felt sorry for Sunder but not that wise alek engineer who didn't seem to understand the gravity of the situation he was in.

I'd like to see a model of the collapse that had all the actual infrastructure based on the final drawings and force it to or back run it so that it mirrors the video we see... then determine what had to have occurred... that would be informative.. to me.

 

[kylebisme]

All of them flown by computer?

It would explain the fancy maneuvering of AA 77 and UA 175, and would eliminate human error from messing up the plan, which would be reason to do it for all. As for the people on board, they could have been simply locked out of the controls, or gassed. Perhaps some kink in that plan is what caused UA 93 to go down in Pennsylvania, or be shot down as Rumsfeld once suggested.

As for the damage to the Pentagon, this page does well to address it, the composite image at the bottom in particular.

 

[kylebisme]

I'd like to see a model of the collapse that had all the actual infrastructure based on the final drawings and force it to or back run it so that it mirrors the video we see... then determine what had to have occurred... that would be informative.. to me.

They made the model, but since it would be impossible to get it to come close to free fall, they only released a short video of it starting to come down. You can see it compared with the real thing here. I'd love to get my hands on the model and tweak it to show how the building actually came down, but they refuse to release it claiming "public safety" reasons. :\

 

[LunarRay]

They made the model, but since it would be impossible to get it to come close to free fall, they only released a short video of it starting to come down. You can see it compared with the real thing here. I'd love to get my hands on the model and tweak it to show how the building actually came down, but they refuse to release it claiming "public safety" reasons. :\

It seems to me that a progressive collapse of the interior structure produces a progressive [Asymmetrical] collapse of the building structure... The model they provide shows that quite clearly. In order to get a symmetrical collapse you need having a symmetrical destruction of the interior structure and have it occur with in seconds of the start to the finish. A fire can't provide that kind of condition unless all the columns are involved and weaken in sync with each other and do so rather quickly. Free Fall can't occur with structure remaining inside... not in this Universe anyhow. (imo)
Perhaps demo experts have found a new way to demo.... Smart fire.

 

[PeshakJang]

Looks like I am right... Kyle can't answer my question.

What a pathetic joke.

 

[William Gaatjes]

It seems to me that a progressive collapse of the interior structure produces a progressive [Asymmetrical] collapse of the building structure... The model they provide shows that quite clearly. In order to get a symmetrical collapse you need having a symmetrical destruction of the interior structure and have it occur with in seconds of the start to the finish. A fire can't provide that kind of condition unless all the columns are involved and weaken in sync with each other and do so rather quickly. Free Fall can't occur with structure remaining inside... not in this Universe anyhow. (imo)
Perhaps demo experts have found a new way to demo.... Smart fire.

Perhaps this is a possibility.
I think if those visco elastic dampeners where used as well, it might provide some answers. Because those dampeners cannot withstand heat.
Another points is that the whole building was bigger then originally planned. As such there was a novel form of construction used. Where the entire weight of the building was transfered to those inner columns. Those columns where part of the electrical power station housing. I would think that a free fall would be possible for the upper floors of the building. The pictures after the collapse show perfectly that the center is still standing. As example The building was build on top of a mushroom shaped foundation. If the upper part of the mush room failed, the whole building would actually come close to free fall. Because the center part of the building would not be able to carry the weight of the entire building. There where cantilevers used to transfer the loads. I read an construction report where the constructors really hated building the WTC7 because of working so close to and partially inside the power sub station.


I wish i could get building records but that would be difficult but i have this :

http://911review.com/reviews/counterpunch/markup/darkfire11282006.html

But i have this information :

WTC 7 was built in 1987 over an existing Consolidated Edison electrical substation. The Con Ed substation was three stories high, and took up the northern half of the footprint of WTC 7. The 1967 construction of the substation accounted for the eventuality of a building above it, and a much larger and stronger foundation was built. Also, a series of columns rose through the area of the substation, for future use.

The design of WTC 7 was larger than anticipated by the provisions of 1967, so additional foundation columns were sunk.
Also, the placement of columns in WTC 7 above Floor 7 did not match all the tops of columns connected to bedrock and waiting to be used. Thus, a series of trusses were designed to transfer the vertical loads above Floor 7 and redistribute them laterally to match the waiting columns below Floor 4. This transition used triangular assemblies of structural steel joined into a framework spanning two stories, Floors 5 & 6.

Part of the transition structure included a Floor 5 made of 11 inches of reinforced concrete on top of a 3 inch 18 gage composite metal deck (supported on I beams); Floor 6 was 3 inches of concrete on a 3 inch 20 gage metal deck; the northern half of Floor 7 was 5 inches of reinforced concrete on a 3 inch 18 gage metal deck, and the southern half of Floor 7 was 8 inches of concrete with two layers of reinforcement (no metal deck). Floors 8 and up (except 21, 22, 23) had 2.5 inches of concrete over 3 inch 20 gage metal decks. These metal decks were sheets of metal with corrugations (metal thickness listed by gage number).

The combination of three massive floors and interconnected triangular supports made the framework of Floor 5 to Floor 7 a diaphragm locking WTC 7 together laterally, core columns and walls (encasing elevator shafts and stairwells) to perimeter columns. The construction of WTC 7 above Floor 7 was similar to that of the WTC Towers (9). The irregular framing between Floors 5 and 7 made for less desirable tenant space, but it was well protected by the robust construction, an ideal location for the building's machinery and the emergency power systems.

Machine Space and Emergency Power Systems

Only machinery resided on Floors 5 and 6. Floor 6 had two large cut-outs, one along the east side, another in the southwest corner, to allow for two-story mechanical spaces. A set of louvers spanned the height of Floors 5 and 6 along the eastern face of the building. Table 1 lists the equipment that resided on Floors 5 through 9 (ground level is floor 0).

Table 1, Machinery on Floors 5 to 9, WTC 7

Floor Items

9 1 generator (1 tank) for (tenant) U. S. Secret Service

8 1 generator (1 tank) for (tenant) American Express

7 3 generators (1 tank) for the Mayor's Office of Emergency Management

6 switchgear, storage

5 11 generators (1 tank), switchgear, transformers.

The "tank" noted in the table would be a 275 gallon diesel fuel tank, the maximum size allowed on any given floor by the NYC Building Code.

There were five emergency power systems in WTC 7. Three of them (American Express, OEM, U.S. Secret Service) drew fuel from the other two and larger systems (Salomon Smith Barney, Silverstein Properties). (1c), (8)

The emergency power for the building (Silverstein Properties) was provided by two 900 kW generators on the southwest corner of Floor 5. They drew fuel from a 275 gallon tank nearby, and this was replenished by pumps drawing from two 12,000 gallon tanks at ground level under the loading dock, at the southwest corner of the building.

The SSB emergency power system used nine 1,725 kW generators on Floor 5: three in the southwest corner, two near the west end of the north face, four at the east end of the north face. Louvers for air intake and exhaust were situated on the building faces near the generators. Because there was already a 275 gallon "day tank" on this floor, the SSB system pumped on demand from their own pair of 6,000 gallon storage tanks, also situated under the loading dock, under the southwestern part of the building.

The fuel supplier was contracted to keep the tanks full, and they were full that day.

Fuel pipes for all systems except SSB ran up the western side of the core of the building, along elevator shafts. The SSB pipes ran up a shaft through mechanical spaces near the southwest corner of the building.

Do you know where the impact into WTC 7 of the debri from WTC 1 was ?

 

[OCGuy]

Hey, if you keep this up, somewhere along the line, someone might listen.

Actually, no. Please devote your time and energy to something productive to society.

 

[MotF Bane]

Hey, if you keep this up, somewhere along the line, someone might listen.

Actually, no. Please devote your time and energy to something productive to society.

Like sweeping floors or picking up litter.

 

[LunarRay]

Do you know where the impact into WTC 7 of the debri from WTC 1 was ?

The southwest corner took the major portion of the Tower provided damage.

I visualize the structure coming down and wonder about a few things. For instance, the exterior was connected to the exterior columns which were connected to the core columns via the beams in a typical 'steel building' construction methodology. That means to me that if the beams failed they had to sorta pull the exterior columns inward or simply dangle there... IF the core columns fail like column 79 then fine it fails and the floors around it fail and on and on.. but the exterior showed no visual sign of this and I think it would have given the connections. I figure I should see major damage reflected in the exterior if there was damage inside. What I do see is the collapse commences with the penthouse falling down.. OK.. that meant the structure below that collapsed somehow. Then I see a few seconds later the entire building accelerate down at free fall... about 100' at least. That meant that the entire column system failed at the same time to allow for symmetrical collapse.

I don't know about the dampers and I too would like to see the 'As built' plans.

I know that everyone who finds WTC7's collapse to be 'weird' is labeled a conspiracy nut... Well... I'm probably a nut but I've no idea which conspiracy was at play... I don't know too many folks expert in the field who can answer the "How" to WTC7. They say could or may or odds are... but they always have an issue with heating of steel and the loss of strength issue since it can't occur simultaneously.

 

[JEDIYoda]

I know that everyone who finds WTC7's collapse to be 'weird' is labeled a conspiracy nut... Well... I'm probably a nut but I've no idea which conspiracy was at play... I don't know too many folks expert in the field who can answer the "How" to WTC7. They say could or may or odds are... but they always have an issue with heating of steel and the loss of strength issue since it can't occur simultaneously.

Rofl...you don`t know any experts personally in the field who are credible....
The only ones who say it`s odd are those conspiracy theorists....quacks...nut jobs, like your brother Kylebisme!!

 

[LunarRay]

Rofl...you don`t know any experts personally in the field who are credible....
The only ones who say it`s odd are those conspiracy theorists....quacks...nut jobs, like your brother Kylebisme!!

It is safe for me conclude, I presume, that you have an opinion concerning the qualifications of the Engineers who have provided me with their insight that is predicated on the notion that you have the requisite qualifications necessary to facilitate such a determination. Further more, it seems you've determined a familial relationship exists between Kylebisme and me and I presume that is because I view this 9/11 tragedy with fully open eyes and have found it to be full of anomalous events as has he. You then defame folks based on their application of their expertise to these anomalous events as I've paraphrased in previous posts calling them 'nut jobs', 'quacks' and 'conspiracy theorists'...

How very inconsequential you must be! I feel badly for you that you need to project in such a manner. It must be simply awful to be a nothing and seek to elevate with untethered rope ladders.

In any event, did you have anything to offer this thread? Perhaps some special insight you'd like to share... some original thought or something productive?

 

[William Gaatjes]

The southwest corner took the major portion of the Tower provided damage.

I visualize the structure coming down and wonder about a few things. For instance, the exterior was connected to the exterior columns which were connected to the core columns via the beams in a typical 'steel building' construction methodology. That means to me that if the beams failed they had to sorta pull the exterior columns inward or simply dangle there... IF the core columns fail like column 79 then fine it fails and the floors around it fail and on and on.. but the exterior showed no visual sign of this and I think it would have given the connections. I figure I should see major damage reflected in the exterior if there was damage inside. What I do see is the collapse commences with the penthouse falling down.. OK.. that meant the structure below that collapsed somehow. Then I see a few seconds later the entire building accelerate down at free fall... about 100' at least. That meant that the entire column system failed at the same time to allow for symmetrical collapse.

I don't know about the dampers and I too would like to see the 'As built' plans.

I know that everyone who finds WTC7's collapse to be 'weird' is labeled a conspiracy nut... Well... I'm probably a nut but I've no idea which conspiracy was at play... I don't know too many folks expert in the field who can answer the "How" to WTC7. They say could or may or odds are... but they always have an issue with heating of steel and the loss of strength issue since it can't occur simultaneously.

Maybe i am wrong but :
It is the same way how in early days metal tools where made. One heats the metal, and it becomes softer and pliable. But it is not at it's melting point.

If you combine all situations it is not that unlikely. Further, for the beautiful collapses, you have to thank the architects and designers for that. Because the buildings where all build with the same building technique. Hence the similar form of collapse. But why the collapse of WTC7 ? Take a box of cardboard. A wooden shelf of the same size and a wooden pole. Stick the wooden pole in the ground. Then attach the shelf on top of the wooden pole. Then lay the cardboard box on the wooden shelf. You can see that the cardboard box has no problem and is not bending. Now take of the shelf and place the cardboard box on top of the wooden pole. Here you can directly see that the weight of the box is transferred to a tiny portion of the bottom of the cardboard box. The same applies for the building of WTC 7. Combine the impact of debris and the fires and the explosions and the wind pushing and as a result structural loss will happen and something will brake. The building techniques used created a very lightweight compared to size building. These same techniques where responsible for the "demolition" style collapses. In any case, i think with or with out prior knowledge of the architects and designers about what would happen if those buildings would collapse (speaking from their perspective during the design in 1960s-70s), they still deserve a big applause for the buildings coming down as they did without causing more casualties then already happened. Because with hindsight, what would you have preferred, the collapse as happened or a tilted building creating more havoc?

The whole point is that the building was not a solid form and neither was WTC 1 or WTC 2. It is a wire frame designed to carry many times its own weight if nothing is compromised. Now you can imagine with all what was happened combined, it is really not that strange that the buildings collapsed.
And that the fema rapport is such a failure, is just that people where appointed who where found before that more on the golf coarse then studying or doing science.

For example You think a pyramid could ever have been build with that same length while having the same footprint and office space ? Not going to happen. It would collapse under it's own weight.

No, there is only one real question : Did the Bush administration have prior knowledge about the attacks or not ?
This is my opinion :
"
If that was the case, i can assure you there was an estimation done about the damage. And probably the idea was that the planes would be shot down or in the worst case scenario the planes would fly into the buildings but with expectation that the building would not collapse because these building where designed not too. Now again, i may be wrong about this but it seemed those visco elastic dampers where added after the design and estimations where complete."

To think about the decision makers :
When you do not have to deal with every day reality, you loose affinity with all around you. And that is what happening with the super rich.

For example, during WW2, people and jeeps and trucks and tanks and planes and boats where given points. These points would resemble the amount of loss for each lost subject. For example, a human would be 10 points. A jeep would be 20 points. A truck 50 points. A tank 1000 points. and so on. Now the more points lost, the greater the financial loss. You can imagine that there where plans drawn where 100 men where send in to save a tank. Because men where cheaper. However, if you would say this directly you would have a problem and as such a point scheme was used.


I quote once again with respect to those visco elastic dampers :

http://www.designcommunity.com/discussion/7595.html

In response to the question of the action of viscoelastic dampers, I wrote:

Viscoelastic (VE) dampers are dependent on both relative velocity and displacement to dissipate energy. VE damping system in Twin Towers is a double-layer shear damper using a 3M material, which is a rubber derivative, glued to steel plate and angle irons. This material will carry some load (which is temperature-dependent and would be less than the two-bolt connection as shown) as it displaces. As installed it has several functions:
1. It develops continuity moment at the end of joist girder, that is, the joist girders will behave as partial continuous members under Dead and Live load. It is partially restrained under Wind load.
2. It restrained the lower chord of the joist girder (in the direction perpendicular to the plane of the joist). Therefore it stabilizes the concrete diaphragm. Note that for a 4-inch thick concrete slab spanning 60 feet, it would buckle if there were no joist girder. It also transfers compression load through bottom chord.
3. Joist girder-column connection is a moment connection.
4. It reduces the energy to be absorbed by the joist girder and the columns under Wind load.

As the temperature rises, 3M materials would loose its load carrying capacity, i.e. its energy-dissipating capacity. This is equivalent as loosing the two-bolt connection because it will act as though there is gaps between the steel plate and the angle irons. As a result, several things would occur:
1. The joist girder is no longer a continuous member. Therefore, even under Dead and Live load, its top chord would rotate more relatively to its supporting column.
2. All the compression or tension force to the diaphragm would go through the top chords only.
3. More rotation between the top chord and its respective column under Wind load.
4. No more lateral restraint for the bottom chord and the joist girder could buckle laterally and the slab diaphragm would follow.

And the result is a tremendous demand on the connection between the top chord and its supporting column.

Let be clear that the VE damping system is a novelty design. First of its kind in the World. First of its kind implemented in a skyscraper. The reason I still think it is a design flaw is that:
In the 60’s and beginning 70’s there are many literatures about plastic design in steel including ASCE manual No 41. From J Heyman to Beedle, they all emphasize the importance of collapse mechanism in Limit Analysis. And in dealing with inelastic behavior such as VE damping system is engaging in Limit Analysis whether you want it or not because you have to think what will happen beyond the device limit.

 

[flexy]

I cant see the two videos/sound files being "evidence" for explosives.

I would believe it if a "demolition expert" would state that its impossible that such "booms" being heard during a "normal" collaps of a building. It could be floors collapsing onto each other which caused those booms BEFORE the actual structure fell down.

There is simply no logical evidence that the sounds heard MUST be explosives - and repeatedly "analyzing" of the videos and sounds doesnt make this any more true.

There is a zillions possible explanations which would explain such "explosion like" sounds, IMO. Just my $0.02

Edit:

The MAIN REASON for the actual collapse of 1/2 was the structural weakening , the whole upper third of the building(s) falling/collapsing downwards and then ONTO EACH OTHER in sort of a domino effect

Citing amateurs who hear those noises and say "i know an explosion if i hear one" is HARDLY evidence..how many new yorkers did hear a skyscraper collapse before in their life? Would you rather say that it would cause NO SOUNDS AT ALL (in the seconds before the actual structure collapses) with all the floors collapsing onto each other, gas lines exploding or whatever? I would actually be very surprised if it would NOT cause "explosion like" sounds.