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Debate! What debate?

So how long after 9/11 was that first pic. taken Ace? Would Judy tell you? That might have some bearing on the amount of debris remaining and the type of fires still burning.

The second one is dust, as you well know.
 
Ace please cease flaunting your stupidity.

Ace there was a dump fire in NJ adjacent to the Pulaski skyway that burned for years. The smoke looked exactly like that in the top photo. And clearly those pedestrians are walking through dust and debris. not smoke.

edit to add
I know this not because I have this 80's NJ punk band compilation album. but I have lived in NJ all my life. :)
 

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Disbelief:

I think the collapse of the Twin Towers was extremely complex. That's why NIST took so long to come up with its collapse model. Trouble is the model itself gets so complex you start to lose any sense of cause and effect. It's a bit like these climate change models..... you can get a believable answer that may be completely wrong. So, I guess I am complaining about NIST's approach and failure to consider the collapse itself. I know that wasn't part of its mandate, etc, etc, but I find it the most interesting part! I hope to see something more convincing one day, but I guess as a Doubting Thomas, seeking direct gnosis, I may have to wait until I stand before my Maker and ask him!

David James:

I have written to NIST and received no reply. I have also contacted Bazant and received some very positive feedback from him and one of his associates.


you can get a believable answer that may be completely wrong. So, I guess I am complaining about NIST's approach and failure to consider the collapse itself. I know that wasn't part of its mandate, etc, etc, but I find it the most interesting part!

You find it the most intersting part? I don't hold that against you. Especially, since I find it to be the only interesting part.

The problem here is that most people live under the illusion that NIST got the mandate to study and explain the collapse itself and did so.
And published the results in the NIST report.

Apparently this is not the case. This sad state of affairs can only be described as a dirty trick to decieve the public.
 
Apparently this is not the case. This sad state of affairs can only be described as a dirty trick to decieve the public.

Thankfully for humanity, your towering intellect was not deceived.

I see a Nobel prize in your future.
 
Ace there was a dump fire in NJ adjacent to the Pulaski skyway that burned for years. The smoke looked exactly like that in the top photo. And clearly those pedestrians are walking through dust and debris. not smoke.

This dump fire may be a good model of the Pile. If we follow Dr. Greening's arguments (which I do not), in order to burn for only a single year, it would have to have been approximately 600 meters deep. Clearly it wasn't, unless the topography of New Jersey has changed dramatically in the recent past.

Are there any studies of this dump fire? Anything similar?

Note that I do not discount additional sources of combustion through unexpected metallic reactions, that would be quite interesting -- but I still see absolutely no evidence that any alternate collapse theory is superior to the NIST hypothesis.
 
This dump fire may be a good model of the Pile. If we follow Dr. Greening's arguments (which I do not), in order to burn for only a single year, it would have to have been approximately 600 meters deep. Clearly it wasn't, unless the topography of New Jersey has changed dramatically in the recent past.

Are there any studies of this dump fire? Anything similar?

Note that I do not discount additional sources of combustion through unexpected metallic reactions, that would be quite interesting -- but I still see absolutely no evidence that any alternate collapse theory is superior to the NIST hypothesis.
Would these provide relevent analysis to similar fires?
http://www.usfa.dhs.gov/downloads/pdf/tfrs/v1i18-508.pdf
http://www.smithsonianmagazine.com/issues/2005/may/firehole.php
http://www.cdc.gov/niosh/mining/pubs/pdfs/2004-167.pdf
http://pangea.stanford.edu/ERE/pdf/IGAstandard/SGW/2005/chiasson.pdf
 
This dump fire may be a good model of the Pile. If we follow Dr. Greening's arguments (which I do not), in order to burn for only a single year, it would have to have been approximately 600 meters deep. Clearly it wasn't, unless the topography of New Jersey has changed dramatically in the recent past.

Are there any studies of this dump fire? Anything similar?

Note that I do not discount additional sources of combustion through unexpected metallic reactions, that would be quite interesting -- but I still see absolutely no evidence that any alternate collapse theory is superior to the NIST hypothesis.

Found some EPA documents that mention the PJP landfill fires that they had to excavate to extinguish.

This document

http://www.epa.gov/Region2/superfund/npl/0200569c.pdf

From this site

http://cfpub2.epa.gov/supercpad/SiteProfiles/index.cfm?fuseaction=second.additional&id=0200569
 
R. Mackey:

Yes, it IS supposed to be how much the floors sagged prior to "global collapse ensuing".

But this is quite insufficient to exceed the elastic strain absorbing capacity of the structure. So can you explain how this works?

There IS a minimum for smoldering combustion. Smoldering rates reported by Ohlemiller at NIST are generally at least 2 x 10^-3 cm/sec. That gives 24 days for the burn through of a rubble pile that is 40 meters deep!
I haven't looked at that paper in some time, and don't have it handy, so forgive the questions here.
Did you account for the Crippling effect that the sagging had on the load-carrying capability of the columns? That would be in addition to the increased length over design on the intact columns where the column-to-floor truss joint had also failed.
Your simple model was effective for describing the energy balance after collapse initiation, but is a little too simple to describe the actual initial collapse, which could be considered to be due essentially to creep.
 
Ace:

We have been through this before on PhysOrg. That picture you posted is meaningless without an approximate date. However, I can tell by looking at it that it was taken long after 9/11. The road is free of dust and debris and there are plenty of recovery vehicles to be seen. Hence we can be sure that a lot of debris had been removed before that picture was taken. So, when you ask where all the mass of the tower has gone, my guess would be it's gone to Fresh Kills landfill!

And Ace, I see no problem with the color of the smoke - smoke can be white, gray, black, blue..... it depends on what's burning, the temperature of the fire, etc, etc...
 
Ace:

We have been through this before on PhysOrg. That picture you posted is meaningless without an approximate date. However, I can tell by looking at it that it was taken long after 9/11. The road is free of dust and debris and there are plenty of recovery vehicles to be seen. Hence we can be sure that a lot of debris had been removed before that picture was taken. So, when you ask where all the mass of the tower has gone, my guess would be it's gone to Fresh Kills landfill!

And Ace, I see no problem with the color of the smoke - smoke can be white, gray, black, blue..... it depends on what's burning, the temperature of the fire, etc, etc...

Another voice of reason in ACE's world of ignorance....thank you.

TAM:)
 
Thankfully for humanity, your towering intellect was not deceived.

I see a Nobel prize in your future.

Tnx, Dave.

I am less then surprised that the Nobel and Pulitzer prize gets mentioned in connection with my name.

But,I have a hard time imagining you getting the Nobel prize. I doubt there ever will be a Nobel prize in BS: ology.

I will also take the opportunity to announce that I withdraw my Stundie nomination. I think I will concentrate on getting those two other prizes mentioned earlier.
 
RWGUINN:

My discussion of the WTC collapse initiation may be simple, but it’s based on the NIST Report. NIST’s key statement concerning the WTC collapse-initiating event, is:

The change in potential energy due to the downward movement of
building mass above the buckled columns exceeded the strain energy
that could be absorbed by the structure. Global collapse then ensued

I take this to mean that prior to collapse initiation the mass above the impact zone slowly slumped ASYMMETRICALLY DOWNWARDS and added strain energy to the columns below. Eventually the lowering of one side of the building was such that the maximum strain energy capacity of the structure was reached. At this critical juncture the columns on the weakened sides of the building underwent rapid failure and the floors above the impact zone pivoted en masse about one side or corner, causing this section of the Tower to fall obliquely on to the floor below.

The mass specific elastic strain energy capacity of structural steel is 57 J/kg. If we take one floor as the minimum size of the impact damage zone for each Tower, and note that the mass of structural steel on one floor is 900,000 kg, the elastic strain energy capacity of one WTC floor is 51.3 MJ.

But we also need to evaluate the plastic strain energy dissipated by the buckling of columns in the damage zone of the towers. This may be estimated from the area under a load vs. vertical displacement curve for a representative WTC column. To determine an effective yielding load, Fy, for the structural steel near an upper level floor we assume that Fy = M15 g x "a safety factor”, which we take to be 2. Thus we find that Fy = 1138 MN. We will assume, following NIST, that the core columns carried 50 % of the structural load. Hence, the average load-to-failure of a core column is estimated to be ~ 12 MN. An estimate of the vertical displacement to failure of a column is needed to evaluate the plastic buckling. Inspection of NIST’s load displacement curves for a WTC tower show that a 0.3 m lowering within the elastic response of the core columns accounts for about 50 MJ – a conclusion that is consistent with my estimate of 51.3 MJ for the elastic strain energy for one floor. The vertical displacement due to plastic deformation of a single column is about 1 meter, from which I estimate the energy for the buckling of the core columns on one floor to be 284 MJ. And please note that this calculation is derived from data in the NIST Report

The tilting of the upper section of a tower is easily included in energy balance calculations using the fact that the lowering of the center of gravity, D, of an upper section (as a function of tilt angle q) is given by:

D = ½ { h [ 1 - cos q ] + w sinq}

where h and w are the height and width of the upper section of the Tower, respectively.

Application of this formula to the tilting of the upper sections of WTC 1 & 2 shows that a 2° tilt was required to bring WTC 2 to collapse initiation while a 4° tilt was required for WTC 1.

Remarkably, however, NIST would have us believe that PRIOR TO COLLAPSE the towers tilted very much more that this as in the NIST Report statements:

“Moments BEFORE it began to collapse the entire section of WTC 2 above the impact zone began tilting as a rigid block (all four faces; not only the bowed and buckled east face) to the east (about 7° to 8°) and south (about 3° to 4°) as column instability progressed rapidly from the east wall along the adjacent north and south walls.”

Or worse yet (also for WTC 2):

“ The building section above the impact area tilted to the east and south. ….
Rotation of approximately 4 to 5 degrees to the south and 20 to 25 degrees
to the east occurred BEFORE the building section begins to fall vertically.”
 
Frank, I've seen you bring up that point for quite some time. Why don't you simply ask NIST about the error. It wouldn't be the first. They DO respond to questions.
 
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I will have to look at this, but I'm not entirely sure you answered my questions.
Strain energy calculation is a useful tool, but structural members don't yield based entirely on strain energy. Individual strain--and resultant stress values--will determine yield and failure of an element. With buckling, things are a bit trickier than I normally handle (I usually go to great pains to avoud it coming close to happening!), so I will take a look at what you say.
Thanks.
 
Ace:

We have been through this before on PhysOrg. That picture you posted is meaningless without an approximate date. However, I can tell by looking at it that it was taken long after 9/11. The road is free of dust and debris and there are plenty of recovery vehicles to be seen. Hence we can be sure that a lot of debris had been removed before that picture was taken. So, when you ask where all the mass of the tower has gone, my guess would be it's gone to Fresh Kills landfill!

And Ace, I see no problem with the color of the smoke - smoke can be white, gray, black, blue..... it depends on what's burning, the temperature of the fire, etc, etc...

But why would the materials be significantly different than what was burning in the standing towers? And how could it be burning hotter with less oxygen? And why would the stuff in the 1st picture be hanging around the ground?

On quantity of material in the footprint, I've given several different lines of data and reasoning to support the position that a very large percentage of the mass was converted to powder and ejected.

1. Photographs at ground zero. Despite your assertions to the contrary, there are a good number of photos taken within days of 9/11. The footprint areas were among the last to have debris removed. There just isn't any proof the idea that all this mass went into the basement, or whatever else you want to believe.

2. The videos of the demolitions. Huge quantities of very dense dust are observed. They are bigger than the towers themselves, and fall very rapidly, outside the footprint. The fall time is proof of high density.

3. The quantity of dust over lower Manhattan. Inches deep over square miles. This is enough to account for most of the mass of the towers.

So, we have three different lines of evidence which all corroborate the idea that a very large percentage of the mass was pulverized and ejected. The idea that >80% of the mass stayed in the footprint is supported by . . . what?
 
Yes, I wrote to NIST and was ignored. It is all so reminiscent of my experience as a nuclear researcher when I wrote to ASTM to notify them they had published fudged data. I was ignored! In the end I phoned them and talked to the editor of the publication in question. He said words to the effect that he had worked for ASTM for 30 years and was retiring in two months so he didn't need this kind of trouble!"
 
Yes, I wrote to NIST and was ignored. It is all so reminiscent of my experience as a nuclear researcher when I wrote to ASTM to notify them they had published fudged data. I was ignored! In the end I phoned them and talked to the editor of the publication in question. He said words to the effect that he had worked for ASTM for 30 years and was retiring in two months so he didn't need this kind of trouble!"

It could of been the tone or the specific contact. I've haven't had many problems contacting NIST. (One contact I have used is Bill Pitts)
Or Bazant for that matter. Although when I first contacted Bazant he wasn't very nice.

I'll be glad to try.
 
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