Why did the WTC columns pull in?

[Tony Szamboti]

Read towards the end of page 109 of Christoper7's "10 storey hole in WTC7" thread, where examples and links are given.

Temperatures of 1000°C in house and office fires are not uncommon.

The temperatures you site are peak temperatures. I don't think anyone would claim peak temperatures exist everywhere in a fire and are certainly not indicative of object temperatures, especially big ones with large thermal capacities and the ability to transfer heat like interconnected steel columns and beams. The link says this straight out.

http://www.doctorfire.com/flametmp.html

Anyway thanks for the link.

If you haven't yet you might want to take a look at the Cardington fire tests, done on a typical steel framed building. The link is here

http://www.mace.manchester.ac.uk/pr...ures/strucfire/DataBase/TestData/default1.htm

 

[Tony Szamboti]

Absolutely correct. Also, NIST's own mockup of the WTC fires hit 1000^o Celsius in almost every sensor location, and one got as high as 1400^oC before destroying the temperature sensors. Appendix C, NCSTAR1-5E.



It isn't even about calibration, it was about testing certification. The experiment was not designed to test large deflections and caternary behavior -- all tests were stopped upon reaching a "maximum midspan deflection" of about eight inches, or sooner. Caternary behavior implies buckling in the truss diagonals, and they explicitly halted before that, since it might destroy the test cell.



As you know -- or should know, anyway -- the antenna drop was a lean, it only looked like a drop from some perspectives. Totally ordinary.

Really, Tony, you're coming across as very poorly informed, given your long association with the JONES.

The antenna drop was a lean!!! Give it a break. That is nonsense. I have looked at that from many directions. The thing comes straight down for quite some time and then finally leans and falls over.

Really, Ryan, you come across as a spin artist sometimes. I guess you need to do that when you are defending a weak story.

 

[R.Mackey]

The antenna drop was a lean!!! Give it a break. That is nonsense. I have looked at that from many directions. The thing comes straight down for quite some time and then finally leans and falls over.

Really, Ryan, you come across as a spin artist sometimes.

Stating facts makes me a spin artist, eh.

I guess I'll just add this to the list of facts that you actively deny. I honestly don't know what you expect to accomplish, since you leave yourself so trivially open for refutation this way...

 

[Tony Szamboti]

Stating facts makes me a spin artist, eh.

I guess I'll just add this to the list of facts that you actively deny. I honestly don't know what you expect to accomplish, since you leave yourself so trivially open for refutation this way...

Back up what you say then and provide a link to a video that shows the antenna leaning over at collapse initiation.

Your statements don't amount to fact, without showing your basis.

 

[R.Mackey]

Back up what you say then and provide a link to a video that shows the antenna leaning over at collapse initiation.

Your statements don't amount to fact, without showing your basis.

NCSTAR1-6, page 153:

Photographic and videographic records were reviewed to identify structurally-related events. Where possible, all four faces of a building were examined for a given event or time period to provide complete understanding of the building response. Observations from a single vantage point can be misleading and may result in incorrect interpretation of events. For instance, photographs and videographic records taken from due north of the WTC 1 collapse appeared to indicate that the antenna was sinking into the roof (McAllister 2002). When records from east and west vantage points were viewed, it was apparent that the building section above the impact area tilted to the south as the building collapsed.

(Emphasis added)

You conspiracy folks have got to learn to stop calling my bluff. It won't work.

 

[beachnut]

The temperatures you site are peak temperatures. I don't think anyone would claim peak temperatures exist everywhere in a fire and are certainly not indicative of object temperatures, especially big ones with large thermal capacities and the ability to transfer heat like interconnected steel columns and beams. The link says this straight out.

http://www.doctorfire.com/flametmp.html

Anyway thanks for the link.

If you haven't yet you might want to take a look at the Cardington fire tests, done on a typical steel framed building. The link is here

http://www.mace.manchester.ac.uk/pr...ures/strucfire/DataBase/TestData/default1.htm

Move those goal posts. I think you paper said it best with respect to evidence of the WTC columns pulling in for your conclusions.

One may wonder who would want people in Afghanistan and Iraq to be blamed if they didn’t do it. A good hard look at the soon to be built U.S. oil company controlled gas and oil pipeline in Afghanistan, and the privatization of Iraq’s oilfields to U.S. oil companies, might be a start at solving that puzzle for oneself. Neither of these situations would have been possible, without the support of the American people, for the use of the U.S. military, to overthrow the previous governments of these countries. (realcddeal)

Your summary for 9/11 WTC failure in your very scientific paper.

Indicative of all your work and posts base in science.

 

[BenBurch]

Now, if a truss heats to the point of significant sagging, when it cools, it will not straighten out and will shorten. How much force could this apply?

 

[Alferd_Packer]

He's simply showing that the structure is unstable at temperature -- the equations do not converge. Buckling (if that's what you are aiming at) doen't even enter the picture-yet.
there is no need for any additional bewilderment of the unwashed masses...

Since the failure was ultimately a buckling failure, I think it's worthwhile to note the inverse square law that kicks in as the floor slabs fail.

All other factors being equal*, if one floor fails, then your critical buckling load is cut to 25%. If two adjacent floors fail, then you're down to 11% of your original capacity. Three floors and you are down to 6.25%. How many floors did the bowing span?

*Now I realize that that is a simplification, but it is a usefull one. At any rate as the floors failed, the structure was significantly weakened.

Furthermore, Euler's law doesn't even take into account the additional lateral force on the columns caused by the sagging floors.

 

[Tony Szamboti]

NCSTAR1-6, page 153:

(Emphasis added)

You conspiracy folks have got to learn to stop calling my bluff. It won't work.

You are bluffing!

That is a misleading statement you cite from NIST. You just can't produce a video showing the antenna leaned over early in its fall can you? I didn't think you could. If the antenna leaned with the building for a moment that was insignificant as it came straight down for over 150 feet, before finally leaning over and falling off. When you you choose to defend a weak story you have to spin things and can only go so far. I understand.

 

[R.Mackey]

You are bluffing!

That is a misleading statement you cite from NIST. You just can't produce a video showing the antenna leaned over early in its fall can you? I didn't think you could. When you have to spin things to defend a weak story you can only go so far. I understand.

Riddle me this, Tony: What kind of "scientist" only accepts evidence in video form?

Do your own damn homework. You should be doubly motivated to catch this one, because you'll not only catch me, you'll catch NIST in a lie. What fun! Knock yourself out.

 

[Newtons Bit]

Now, if a truss heats to the point of significant sagging, when it cools, it will not straighten out and will shorten. How much force could this apply?

Not enough to cause the building to collapse. Though it would be serious enough to warrant repairs or even demolition of the building afterwards. Sometimes repairing that sort of thing is impossible.

 

[rwguinn]

You are bluffing!

That is a misleading statement you cite from NIST. You just can't produce a video showing the antenna leaned over early in its fall can you? I didn't think you could. If the antenna leaned with the building for a moment that was insignificant as it came straight down for over 150 feet. When you have to spin things to defend a weak story you can only go so far. I understand.

That is an idiotic posting. You cannot possibly be that ignorant.
The Antenna didn't lean by itself. It rotated with the top of the building it was attached to! QUIT MOVING THE DAMN GOALPOSTS!
You know this, you can see it in the video--the top block began its collapse on one side. The antenna went with it.

 

[Tony Szamboti]

That is an idiotic posting. You cannot possibly be that ignorant.
The Antenna didn't lean by itself. It rotated with the top of the building it was attached to! QUIT MOVING THE DAMN GOALPOSTS!
You know this, you can see it in the video--the top block began its collapse on one side. The antenna went with it.

Okay rwguinn, produce a video to back up your assertions.

The antenna did lean by itself at the end of its fall with the building and fell to the side.

 

[rwguinn]

Okay rwguinn, produce a video to back up your assertions.

The antenna did lean by itself at the end of its fall with the building and fell to the side.

So, you admit you were wrong, and that the antenna did not drop straigth down first, but that it did lean after the building parts contacted each other?

Good for you.

 

[Tony Szamboti]

So, you admit you were wrong, and that the antenna did not drop straigth down first, but that it did lean after the building parts contacted each other?

Good for you.

I also said that it was insignificant and don't believe that was the cause of the differential drop in the antenna and the perimeter roofline.

Where is the video which shows us the amount of lean you need to quell the assertions that the antenna dropped into the roof before the perimeter roofline moved?

I'll bet you can't produce one and are only exaggerating the slight initial upper block lean's effect on the antenna to eliminate a piece of evidence for the central core failing before the perimeter.

 

[e^n]

All of it from the fire affected areas. I don't know that it was NIST who did the recovery. Do you?

NIST participated in surveys of the debris sites and selected samples for recovery I believe. I'm not entirely sure if they were part of FEMA/BPAT as I haven't looked into this too much. However your statement is very odd, do you think that they didn't recover all of the steel intentionally?

Ryan Mackey will disagree but it would certainly seem that the UL floor assembly fire tests were about more than just calibration. That is silly on its face.

Ryan has already dealt with this (should I say Mr Mackey?) but this claim is so especially silly I thought I would mention it specifically. The UL test trusses were not only fully fireproofed and shorter than the trusses on sagging sides, they did actually begin to fail in the same manner!
Your statement that it "certainly seems" like they were for more than calibration is pure speculation based only on a Conspiracy Theorist talking point. Please don't follow Kevin Ryan's bad example and completely lie to try and make a point. These tests were not for determining post impact performance and it is very clear why that is impractical.

The antenna drop on the North Tower, before the perimeter roofline starts to fall, is one quick example. Sudden onset and complete failure of a large somewhat non-interdependent steel frame is a circumstantial, although not definitive proof, for CD. It is highly unusual for fire.

This isn't exactly what I am asking, you are speculating here and stating if the antenna failed and began to drop straight down (it didn't, we will get to that shortly) it would be evidence of a controlled demolition. But this sort of evidence (inferred) has already been provided in ample amounts for the 'official story'. I asked you for a type of evidence that the controlled demolition theory has that the 'official story' lacks. An example would be observation of a cut pattern on steel columns with no other plausible explanation. This would be direct physical evidence of intentional failure, something that the 'official story' really doesn't have in the same manner.

Now as for the antenna on the North Tower, it's a common claim that it dropped straight down, and a classic example of this can be found here: http://911research.wtc7.net/wtc/evidence/videos/wtc1_close_frames.html

If you examine closely you'll notice that in fact the first structural movement ouside the antenna is noticed in frame 7, as little as 1/2 a second after the initial moment was visible. However there are pictures available in the NIST report (and annotated by Mangoose):

This is also visible in this clip from 911research, although I am not aware of a source for video including the first 2 seconds I will review my TV archive when not at work.
http://911research.wtc7.net/wtc/evidence/videos/wtc1_nbc1.html

In my opinion you should at least read the NIST report, like many 'truthers' you seem to be parroting points you've only heard and seen supported in 'truther' documentaries. Do some research of your own and you'll rapidly find that most of these conclusions are tenuous at best.

I'll bet you can't produce one and are only exaggerating the slight initial upper block lean's effect on the antenna to eliminate a piece of evidence for the central core failing before the perimeter.

I am not exaggerating anything, nor trying to eliminate evidence. The existence of bowing columns on both towers followed by a failure and upper section tilt towards that side suggests a similar failure mechanism. It's your burden of proof to talk about the core.

 

[funk de fino]

The temperatures you site are peak temperatures. I don't think anyone would claim peak temperatures exist everywhere in a fire and are certainly not indicative of object temperatures, especially big ones with large thermal capacities and the ability to transfer heat like interconnected steel columns and beams. The link says this straight out.

http://www.doctorfire.com/flametmp.html

Anyway thanks for the link.

If you haven't yet you might want to take a look at the Cardington fire tests, done on a typical steel framed building. The link is here

http://www.mace.manchester.ac.uk/pr...ures/strucfire/DataBase/TestData/default1.htm

Ah, so you switch from you 1000 deg F claim?

I can get experiments and papers that say normal temps reached in office and household type fire reach 1000 deg C easily and can reamain at that temp as long as there is fuel and air. One test done in natural ventilation had temps above 600 deg C for over 18 mins. What temp does steel start to lose significant amounts of its strength?

If I get you the links will you retract?

transfer temps where? Did you see the size of those fires?

You are a poor engineer blinded by political bias. Very very sad to see.

And we have not even mentioned your lies yet.

 

[BenBurch]

Not enough to cause the building to collapse. Though it would be serious enough to warrant repairs or even demolition of the building afterwards. Sometimes repairing that sort of thing is impossible.

Can you IMAGINE the engineering problem taking down those buildings would have presented had they not collapsed?!

And there would be a LOT of political pressure to allow tenants to remove essential paperwork and computer equipment; Insurance would likely NOT have covered the losses had the equipment not been destroyed but instead had been locked in the damaged building pending demolition. Likely the Port Authority would have had the whole loss come down upon it in the form of a lawsuit.

And allowing the tenant's evacuation teams back into a creaking, twisted building! Well...

I am not sure I can think of any way to stabilize the structure, and it would have been close to collapse from the start.

Can you imagine the first day of high gusting winds?

 

[e^n]

To my utter amazement there is a video showing the south side of the north tower! I didn't think that this existed but apparently it does, this should hopefully convince you realcddeal.

http://www.youtube.com/watch?v=xR4qOo6XY-Y&feature=user

 

[funk de fino]

That video quite clearly shows part of the core standing for a considerable time after the collapse IMO