Why did the WTC columns pull in?

[e^n]

Nice partial job. Now you need to finish the job and do the graphs for the steel beam and column temperatures, from the Cardington tests. Then we can have a discussion.

The column temperatures are not relevant as they were protected over their height in this particular test. However I am more than happy to graph beam elements for you. Here are two secondary beam elements either side of the chamber and a central primary element:







I am unsure how exactly this serves your point as all three achieve a dangerously high temperature quite quickly (not fireproofed) and retain that heat for quite a while. Please feel free to make whatever point you would like to.

 

[Newtons Bit]

I accept that fire increased bowing. I just wanted to how cutting more columns would affect bowing.

Thanks

You're still not quite getting it. Cold and under 6kips of loading it deflect abouts 0.2 inchs. I'd expect it to deflect no more than 1inch under 24kips of loading (the probable maximum of the connection). It's not noticeable.

 

[BenBurch]

You're still not quite getting it. Cold and under 6kips of loading it deflect abouts 0.2 inchs. I'd expect it to deflect no more than 1inch under 24kips of loading (the probable maximum of the connection). It's not noticeable.

Actually, I'd think it would be a bit less than that, cold. Now, my recollection of this goes back many years, but I recall that an element under compression resists side bending more strongly than that element were it not transmitting a load.

Or am I confused here? The effect I recall reading about was small.

 

[Sizzler]

You're still not quite getting it. Cold and under 6kips of loading it deflect abouts 0.2 inchs. I'd expect it to deflect no more than 1inch under 24kips of loading (the probable maximum of the connection). It's not noticeable.

It isn't noticable if no fire is there. Obviously there was fire. Lets assume that the steel was less hot and therefore the floors sagged less. Now, if more core columns were actually severed than NIST reports (a lot more), would that cause observed effects or something to the sort?

Or, would we observe less bowing than we actually did under the above conditions?

 

[e^n]

It isn't noticable if no fire is there. Obviously there was fire. Lets assume that the steel was less hot and therefore the floors sagged less. Now, if more core columns were actually severed than NIST reports (a lot more), would that cause observed effects or something to the sort?

Or, would we observe less bowing than we actually did under the above conditions?

Your question is too vague to give specific answers I suspect and while severing more columns would likely increase bowing it would appear that it is most sensitive to steel temperature. From the graphs I posted above you can see in normal office fires the temperature of unprotected elements rapidly increases to levels capable of severely weakening steel. Why do you appear to be trying to fit some sort of CD theory in with what you would appear to have accepted is evidentely fire weakening?

 

[Tony Szamboti]

The column temperatures are not relevant as they were protected over their height in this particular test. However I am more than happy to graph beam elements for you. Here are two secondary beam elements either side of the chamber and a central primary element:

[qimg]http://xs124.xs.to/xs124/08092/pro10624.png[/qimg]

[qimg]http://xs124.xs.to/xs124/08092/pro11133.png[/qimg]

[qimg]http://xs124.xs.to/xs124/08092/pro4483.png[/qimg]

I am unsure how exactly this serves your point as all three achieve a dangerously high temperature quite quickly (not fireproofed) and retain that heat for quite a while. Please feel free to make whatever point you would like to.

I haven't seen those temperatures on the steel from the Cardington tests. Most of them were in the 500 degree C range without fireproofing. I'll have to look and see where you got these temperatures from.

 

[e^n]

I haven't seen those temperatures on the steel from the Cardington tests. Most of them were in the 500 degree C range without fireproofing. I'll have to look and see where you got these temperatures from.

I picked 3 at random from Test 4, perhaps you could pick the element and test and I shall plot those for you?

 

[Alferd_Packer]

realcddeal, have you read this?

http://fire-research.group.shef.ac.uk/Downloads/SC_Baltimore.pdf

Please do so and tell us what you think of it.

Thanks

(it's not all that long or complex)

 

[Tony Szamboti]

realcddeal, have you read this?

http://fire-research.group.shef.ac.uk/Downloads/SC_Baltimore.pdf

Please do so and tell us what you think of it.

Thanks

(it's not all that long or complex)

I read it over briefly and it is interesting. Let me study it more and I will respond later.

 

[Newtons Bit]

It isn't noticable if no fire is there. Obviously there was fire. Lets assume that the steel was less hot and therefore the floors sagged less. Now, if more core columns were actually severed than NIST reports (a lot more), would that cause observed effects or something to the sort?

Or, would we observe less bowing than we actually did under the above conditions?

You might get something like a 500c fire and full loading of the connection to reproduce those deflections. Or 450c. I'd have to run the numbers. The obvious point is that when steel is heated to those temperatures, the fire protection has failed. It is damaged, or insufficient. I'll let others debate the merits of those two, but the obvious 800 pound gorilla in the truther china shop is that the fires did heat the steel up significantly.

 

[Newtons Bit]

Actually, I'd think it would be a bit less than that, cold. Now, my recollection of this goes back many years, but I recall that an element under compression resists side bending more strongly than that element were it not transmitting a load.

Or am I confused here? The effect I recall reading about was small.

A member under axial and bending loading has more STRENGTH than a member loaded only in bending or only in axial. Compression in a member will magnify the bending moment however. This isn't usually a big concern, as members that are supposed to be doing both are generally nice big wide-flange which only deflect a very small amount under bending.

 

[funk de fino]

One question I would like to see answered.

If the building was in pristine condition (no plane hit) and the same fire was present in the building, would the failure have been the same?

Same timings? Same bowing? Same progressive collapse?

From looking at the Cardington tests it would seem to me there would have been a big difference if none of the perimeter or core colums had been cut/damaged. The loads on the colums would have been different so the loss of strength due to heat would affect the colums in a different manner.

In the same way I guess is the fact that if the fires had been extinguished then the damage due to planes would have not destroyed the building.

 

[e^n]

I haven't seen those temperatures on the steel from the Cardington tests. Most of them were in the 500 degree C range without fireproofing. I'll have to look and see where you got these temperatures from.

You have yet to provide me with a specific element to graph, so I went looking. Even in the protected edge beams in Test 4 the temperature exceeds 500C and often 700C. I also looked at Test 2 in which temperatures seem to be consistent with what I have presented so far.

I believe your statement to be incorrect and challenge you to back it up

 

[R.Mackey]

One question I would like to see answered.

If the building was in pristine condition (no plane hit) and the same fire was present in the building, would the failure have been the same?

Same timings? Same bowing? Same progressive collapse?

That is the $64,000 question. I spend about 20 pages on this in my whitepaper.

Opinions vary. NIST says no. Purdue says maybe. Arup says probably. Dr. Quinitere says yes.

It's also difficult to answer because the impact and fire are not truly separable. If you don't have the perimeter column damage, you probably don't have the massive window and floor breakage, either, and your fire is likely to be smaller and poorly ventilated. You also probably don't have the extensive fireproofing damage. It may be that the answer is "yes," but such a combination is so unlikely that it can be disregarded.

This is real questioning of the NIST Report -- not bogus nonsense about explosives and thermite. It's important to future building design. Several excellent teams are trying to answer this as we speak.

 

[e^n]

I believe your statement to be incorrect and challenge you to back it up

Bumping for realcddeal, I can extract any data you like but I have yet to see you present evidence for the temperatures involved other than your own recollection.

 

[Max Photon]

The $64,000 question is: What is the distribution of final outcomes from jet impacts

That is the $64,000 question. I spend about 20 pages on this in my whitepaper.

Opinions vary. NIST says no. Purdue says maybe. Arup says probably. Dr. Quinitere says yes.

It's also difficult to answer because the impact and fire are not truly separable. If you don't have the perimeter column damage, you probably don't have the massive window and floor breakage, either, and your fire is likely to be smaller and poorly ventilated. You also probably don't have the extensive fireproofing damage. It may be that the answer is "yes," but such a combination is so unlikely that it can be disregarded.

This is real questioning of the NIST Report -- not bogus nonsense about explosives and thermite. It's important to future building design. Several excellent teams are trying to answer this as we speak.

I would think the $64,000 question is:

If one ran a 100 trials of crashing jets into the towers, what would be the distribution of final outcomes, such as:

• % no collapse
• % partial collapse
• % total collapse

Since real trials couldn't have been done, I suspect MILDEC planners ran enough computer simulations to realize that they couldn't count on total collapse (and total collapse was the objective for many reasons). To ensure total collapse, planners helped the fires.


Max

 

[pomeroo]

I would think the $64,000 question is:

If one ran a 100 trials of crashing jets into the towers, what would be the distribution of final outcomes, such as:

• % no collapse
• % partial collapse
• % total collapse

Since real trials couldn't have been done, I suspect MILDEC planners ran enough computer simulations to realize that they couldn't count on total collapse (and total collapse was the objective for many reasons). To ensure total collapse, planners helped the fires.


Max

It's remarkable how badly you think. You're still stuck on the same fallacy. Your imaginary conspiracy wanted to start a war (for incomprehensible reasons). They accomplished this feat by flying planes (how exactly?) into buildings.
They did not want to contribute to an economic downturn for which Bush would be blamed. The collapses of the Towers had a devastating effect on the economy of NYC, worsening and lengthening the recession that began at the end of Clinton's second term. The Impossibly Vast Conspiracy had absolutely no reason to bring down the Towers.

You are fixated on a motive that makes no sense whatever.

 

[R.Mackey]

I would think the $64,000 question is:

If one ran a 100 trials of crashing jets into the towers, what would be the distribution of final outcomes, such as:

• % no collapse
• % partial collapse
• % total collapse

Since real trials couldn't have been done, I suspect MILDEC planners ran enough computer simulations to realize that they couldn't count on total collapse (and total collapse was the objective for many reasons). To ensure total collapse, planners helped the fires.


Max

Well, Purdue took a shot at that, and they've run numerous computer trials. The things that forces you to make so many computer trials are the simplifications -- can you treat steel with a simple stress-strain curve, or do you need a detailed one? Treat all steel the same or not? What's the average strength of office furnishings? etc. All things that the NWO would also have to estimate.

Purdue is finding that these assumptions make a pretty significant difference with respect to the impact damage. However, they also find that they don't make a significant difference with respect to the final outcome -- they conclude that the fire can finish off the building for all of the various impact results.

Models are, of course, imprecise and limited to their assumptions. But if we accept the Purdue results as representative, we conclude that the likelihood of an impact leading to a total collapse is ~90+%. It will not be 100%, of course. Survival is possible, it merely appears to be rare. Whether it's 10% "rare" or < 1% "rare" we may never know.

So I would agree with you, up to a point. If there was a shadowy NWO cabal, they probably would conclude that collapse was likely but not guaranteed. If collapse was absolutely required, they probably would hit it with a little something extra.

Where I disagree is what they would choose to do with this knowledge. I think they'd choose to hit the structures with 747's and wipe them out at once. Cheaper, simpler, faster, safer. Same outcome. I would never in a million years expect them to try to mitigate a potential risk, that the 767's wouldn't be enough, by introducing the phenomenal risk of radical and complicated incendiaries. That's just silly. Either they're risk averse, or they're not. Your hypothesis requires that they're both.

 

[BenBurch]

R.Mackey - without those huge vent holes, I wonder if a fire of this magnitude would have enough oxygen?

 

[R.Mackey]

R.Mackey - without those huge vent holes, I wonder if a fire of this magnitude would have enough oxygen?

I've pointed that out myself numerous times, including in my post one before Max's.

However, the hole created by the impact is almost invariant. It's the internal damage that's dependent on lots of minor contributing factors. The NWO would conclude that the big ventilating hole was not something they needed to worry about.

Also, as Max will tell you, thermite needs no external oxygen source.