WTC7 Revisited

[DGM]

The trading floor?

NIST suggests those events were related to failures lower in the building. If we suppose they were, a number of members and or connections failed. How many members and connections needed to be intact for the building to remain standing? Enough to support the weight anyway.

Yes but only enough to hold the wall (or face) that we could see. I think a major issue with analyzing this collapse is the lack of vantage points that it was seen from. We simply don't know what was happening on the other side of the building. Was sections of windows blowing out? I don't know. Did it start to drop before the face we could see?

Simply put I think there are too many variables to assume the collapse time as far as determining the energy used from acceleration of air.

 

[Major_Tom]

From the point of view of questionable circumstances involved in the collapse of WTC 7, there are 3 points which strike many people as odd.

1) Fall time and resistance (which you are covering now)
2) A symmetrical fall straight downwards.
3) The very odd looking resultant pile of rubble.

Concerning #3, there is a good collection of photos, many of which you may not have seen before, available at the following link:

http://www.sharpprintinginc.com/911/index.php?module=photoalbum&PHPWS_Album_op=view&PHPWS_Album_id=11&MMN_position=138:138

I got these photos from a talented archivist who just recently made his collection public.


The 3 points above stand out to many people as "fishy".

Any help our engineers can give to clarify these points would be appreciated.

 

[GregoryUrich]

Yes but only enough to hold the wall (or face) that we could see. I think a major issue with analyzing this collapse is the lack of vantage points that it was seen from. We simply don't know what was happening on the other side of the building. Was sections of windows blowing out? I don't know. Did it start to drop before the face we could see?

Simply put I think there are too many variables to assume the collapse time as far as determining the energy used from acceleration of air.

So if the entire inside of the building fell down inside. What potential energy was left to drive out the air?

Do we see a jet of smoke and dust ejecting out of the top of the building where the penthouses were?

 

[Major_Tom]

A forth and final(?) issue would be how the fall seemed to be predicted.

The BBC thing was a bit odd.

 

[einsteen]

Gregory, just like the wtc you can find a relation between the collapse energy per floor and the mass per floor in two ways. Look at the acceleration of the drop, assume a "crush down", no pancaking needed and you find immediately the ratio between those values. The other option is to calculate the collapse time as function of the energy to destroy a story and the mass, it seems that this ratio could be fitted using a collapse time of 6.6 seconds. They should be the same of course. An other interesting thing is that if you assume that the collapse is complete (which was the case) there is also a upper value of the collapse time, I remember it was about 7.4 which means that it could never take 10 seconds for example. The drop of the penthouses is not part of the crush-down but part of pre-weakening activities.

 

[GlennB]

Where would the dust and smoke eject? At the damaged South side?
That the E Penthouse spent 6 or so seconds collapsing into the building prior to "global collapse" is undeniable.
That the structures previously supporting it must have failed to provoke this collapse is also (to my mind) also undeniable.
Therefore significant (some might say massive) interior damage was occuring for about 6 seconds prior to "global collapse".
That "global collapse" is always taken to mean the total collapse of the main structure - when all we actually see is the collapse of the N+W sides - might be of significance in any analysis you make.

 

[Sabrina]

Every photo I've seen of the north face of WTC7 (which, granted, aren't many, but they do exist; Aman Zafar's page has a few as well as some other places) had smoke literally pouring from what looked like the entire north facing facade. Video footage as I recall supports that as well; video from later in the day focused on WTC7 shows the smoke billowing from the building on all floors that are visible. That would seem to suggest that numerous windows were broken out on the north face and were obscured by the smoke in addition to the giant gashes in the facade of the building. When the penthouses fell in, the smoke and dust from debris already had a ready egress; it didn't need to billow largely from the top of the building, as it had the broken windows and huge gashes on the north face to exit from. I'd be interested in trying to note if there was a momentary increase in the smoke billowing from the building immediately subsequent to those penthouse collapses; I never paid much attention before, but this has piqued my interest. I'm going to try to find some videos in the archive to see if there's any evidence of that.

 

[Major_Tom]

Does anyone have a photo of the supposed 10 story gash in WTC 7, or is the only evidence eyewitness testimony?

I have photos of the walkway going over the street to WTC 7 that has no large WTC 1 debris on it at all (in the album mentioned a few posts ago). I also have a photo of the southwest corner (taken from the northwest so you can only see the west facade) that does not show a gash.

This leaves only a small space along the south face, on the west side, for the gash to occur. I am not seeing any signs of large debris making it over the street along the south facade of WTC 7.

 

[beachnut]

Big giant holes, broken windows. Let me see; closing the car door against air resistance with closed window, is more than with open windows. WTC7, open windows.

Major portions of WTC7 had fallen internally, and the unique design of WTC7 makes an amateur approach quite laughable.

The major smoking gun to find a no evidence truther is when they bring up WTC7. It means you have found someone with zero evidence just like the rest of 9/11 truth.

 

[aggle-rithm]

I have trouble with a convincing motive too. Maybe we are looking a huge design flaw or shoddy construction.

I'm voting huge design flaw...although it was really a systemic problem. Building codes had become too lax in New York, from what I've heard of more qualified people.

However, regardless of design or construction, the structure should give significant resistance.

It did. One of the tallest buildings in the world FELL ON IT. Not the entire mass, of course, but still...the fact that it didn't immediately collapse is testament to its significant resistance.

 

[aggle-rithm]

A forth and final(?) issue would be how the fall seemed to be predicted.

The BBC thing was a bit odd.

Not really. There have been many instances of a news organization jumping the gun and reporting something that was likely to happen but had not happened yet, or in fact never happened at all. Ever seen the "Dewey Defeats Truman" headlines? How about the network news anchor who reported James Brady dead after the Reagan shooting in 1981? Brady STILL hasn't died.

How about the reports on 9/11 that the State Department had been bombed? Do you think someone was SUPPOSED to bomb it, but forgot?

 

[aggle-rithm]

Does anyone have a photo of the supposed 10 story gash in WTC 7, or is the only evidence eyewitness testimony?

I have photos of the walkway going over the street to WTC 7 that has no large WTC 1 debris on it at all (in the album mentioned a few posts ago). I also have a photo of the southwest corner (taken from the northwest so you can only see the west facade) that does not show a gash.

This leaves only a small space along the south face, on the west side, for the gash to occur. I am not seeing any signs of large debris making it over the street along the south facade of WTC 7.

[C3PO]

Funny, the damage doesn't look that bad from here...

[/C3PO]

 

[Pardalis]

Why is it so hard for some people to wait for the final report?

 

[Sabrina]

Possibly because NIST keeps promising it and keeps pushing the release date back.

I know I'm impatient for it and getting more and more irritated the longer it takes. But that's me personally.

 

[NobbyNobbs]

I used a bottom-up collapse.

I can't say I know much detail about this topic, but doesn't using a bottom-up collapse model presuppose the conclusion you are reaching? That is, by saying the collapse is bottom-up, aren't you already setting the conditions for a controlled demolition?

Then again, maybe my head is bottom-up. Please correct me if I'm wrong.

 

[DGM]

So if the entire inside of the building fell down inside. What potential energy was left to drive out the air?

Do we see a jet of smoke and dust ejecting out of the top of the building where the penthouses were?

If the whole building did collapse like that the air would stay where it is and the exterior walls would fall past it.

This is exactly what I'm referring too. I believe that with out pressurizing the air or having to move large volumes of air at great velocities the energy required would be quite low. Your calculations appear to be worst case (or best depending on how you look at it).

Now I admit I don't know exactly how to do the calculations to support my case but I do understand the principles and I believe my logic is sound. I do however encourage (and quite frankly hope) any of the resident engineers to point me in the correct direction if my thinking is in error.

 

[GregoryUrich]

I can't say I know much detail about this topic, but doesn't using a bottom-up collapse model presuppose the conclusion you are reaching? That is, by saying the collapse is bottom-up, aren't you already setting the conditions for a controlled demolition?

Then again, maybe my head is bottom-up. Please correct me if I'm wrong.

I use bottom-up because that's what is looks like. We know it wasn't top down. Anyway bottom up dissipates the least amount of energy and has the most energy available early in the collapse. If I was suggesting bottom-up for WTC1, you would have a valid point.

 

[Pardalis]

Possibly because NIST keeps promising it and keeps pushing the release date back.

I know I'm impatient for it and getting more and more irritated the longer it takes. But that's me personally.

I blame that on the internet generation.

Nobody waits anymore. The concept of "in due time" seems to be disappearing.

 

[GregoryUrich]

If the whole building did collapse like that the air would stay where it is and the exterior walls would fall past it.

This is exactly what I'm referring too. I believe that with out pressurizing the air or having to move large volumes of air at great velocities the energy required would be quite low. Your calculations appear to be worst case (or best depending on how you look at it).

Now I admit I don't know exactly how to do the calculations to support my case but I do understand the principles and I believe my logic is sound. I do however encourage (and quite frankly hope) any of the resident engineers to point me in the correct direction if my thinking is in error.

I'm pretty sure you can see the roof in one of the collapse videos so at least some air would be forced out of the holes where the penthouses were. My point is and has been that it is not realistic to assume that there was significant collapse inside the building until the roof moved.

Also large volumes of air were moved as indicated by the the huge dust clouds spreading out from the bottom of the building.

 

[GregoryUrich]

I'm voting huge design flaw...although it was really a systemic problem. Building codes had become too lax in New York, from what I've heard of more qualified people.

It did. One of the tallest buildings in the world FELL ON IT. Not the entire mass, of course, but still...the fact that it didn't immediately collapse is testament to its significant resistance.

Significant resistance during the collapse. The building could and did hold itself up for quite a while after being damaged.