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WTC Bldg #7
12

WTC Bldg #7

WTC Bldg #7

(OP)
I was somewhat taken aback by watching this video posted on another forum.  What is the general opinion of structural engineers on the theory of a "controlled demolition" of this building?
 

BA

RE: WTC Bldg #7

Yes, it certainly resembles controlled demolition.  I've seen and filmed a similar size demolition.

I'm not ready to believe a conspiracy theory, however.  There are several probable explanations for this (not counting the conspiracy theories)...who knows what really happened.

 

RE: WTC Bldg #7

You need to do a litle reading and further investigation BA on your own.  There's a lot out there.

There are a lot of unanswered questions here.  There are a lot of crazy ideas that you will see, but there are very good scientifically based reasons for doubt of the government explanation, and not only for Building 7.  Just use your common sense as a structural engineer.    

Mike McCann
MMC Engineering

 

RE: WTC Bldg #7

I'm not buying any of these WTC conspiracy stories, although it's odd that the Verizon Building and the Post Office survived. Of course "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."

Now on the other hand, I'm still not convinced Oswald was a lone gunman. I used to think Gerald Ford was going to make a statement about this before he died, being that he was the last surviving member of the Warren Commission.

RE: WTC Bldg #7

2

Quote:

There are a lot of crazy ideas that you will see, but there are very good scientifically based reasons for doubt of the government explanation, and not only for Building 7.  Just use your common sense as a structural engineer.


I have yet to see a single good scientifically based reason for doubt.  The conspiracy theorists claims invariably take any evidence that appears to support their claim as being absolutely correct and indisputable, and simply ignore any evidence that does not support their claims, even when it comes from someone who they have just said can be believed without question.

If WTC7 collapsed through the mechanism given in the official investigation, why wouldn't it look like a controlled demolition?  

Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
 

RE: WTC Bldg #7

I do understand what your are saying.  

However, I guess my main question, of many, is "how do you get what looks like a controlled demolition failure from what appears to be an unsymmetrically placed fire/demolition event causing the failure?"  It just does not add up to me.  

So, I still have a lot of questions...

Mike McCann
MMC Engineering

 

RE: WTC Bldg #7

Something to think about: Why would the government want to bring WTC7 down? The towers collapsed about 8 hours earlier.AND, as much as I criticize the Federal government I don't believe they were responsible for 911.  

RE: WTC Bldg #7

2
In addition to providing the connection design for the new WTC 7, our firm had access to the Ground Zero site  very soon after the search and rescue efforts ended.  Historically WTC 7 represents the only steel highrise structure to collapse due to fire.   With the other crises and urgency of the tower evacuations, WTC 7 was evacuated and left predominantly to nature's course.  There is not conspiracy here, all attention and personal were focused on the evacuation of the towers.   

http://www.FerrellEngineering.com

RE: WTC Bldg #7

Look at a program about the real controlled demo of a building. There are weeks of preparation, drywall must be removed to allow drilling, wires must be run to the control point, The charges are not placed until the last moment. All this must have gone on in two buildings where work was going on 24 hours a day because the world trading floors don't stop work, without anyone noticing it.

The kicker for me is that in controlled demo, they don't fire all the charges at once, they fire the inner ones first to make sure that the debris falls inward.

Michael.
Timing has a lot to do with the outcome of a rain dance.

RE: WTC Bldg #7

Paddingtongreen:

I have wrestled with the same concerns.  However, not knowing all the facts to come to an irrefutable conclusion, which we never really will as Ron mentioned, the possibility still remains that it could be done.  I'm not saying that it was, only that with the proper control and set of circumstances, it could have been done.  

And I do concur with your final sentence in that it was obvious to me from the video that the interior columns failed first in Building 7.  Coincidence or planned?  Who knows.  It's just a  suspicious occurrence.

It might be possible for one building to fail, looking like a controlled demo.  The problem I have is all three falling in their respective footprints.  What is the likelihood of that?

Just some thoughts to ponder.  I will be quiet now.

Mike McCann
MMC Engineering

 

RE: WTC Bldg #7

Giving the main reason for collapse of the two towers, burning jet fuel, exterior columns destroyed, load path rearranged, I expect the towers to fall just as they did, as if each floor collapsed on the one below it and so on.  As each floor failed and became part of the dynamic mass impacting the floor below it, any outside forces whatsoever couldn't not deter the failure path, which was straight down.

Regards,
Qshake
pipe
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
 

RE: WTC Bldg #7

I'm a licensed SE.  

I do NOT think this was controlled demolition.

None of the shots are showing the other face of the building, the face that sustained most of the damage.  There were confirmed reports of blazing fire on the lower floors by the firefighters who didn't have enough water pressure to fight.  You can see the fires in one or two of the clips.  If you look carefully at the top penthouse, you can see the damaged portion of the building going first.  

This building lost its core at the base from out of control fires that burned for hours.

RE: WTC Bldg #7

The video starts off by claiming that there were explosions consistent with demolition, yet, less than 5 minutes later, starts talking about thermite.  If thermite, the no explosions.  If explosions, then no thermite.  Can't and don't need or want both.  

And, what's the point of taking down WTC7?  If the government was involved in taking down WTC1 and WTC2 and was good enough to make that happen on schedule with the plane impacts, then why the ineptitude in taking down WTC7?

Conspiracy theorists are great at claiming nefarious and extraordinary secrecy and expertise on the one hand, yet, these same perpetrators are so inept at leaving so much evidence  to the contrary.  Again, either they're good, or they're not.  If they're that good, then there should be no evidence to the contrary; there should be no smoking thermite guns.  

The video claims that signs of thermitic reactions were eseentially EVERYWHERE their witnesses looked.  Why?  It takse very little in the way of exposives to do a controlled demo.  Likewise, the amount of thermite required to do the same should be equally small, and being buried in the bottom of the rubble, there should be very little evidence of thermite.  If there's such massive signs of thermite, then the conspirators were both inept, stupid, and incompetent.  Yet, they managed to get away with it?

As with the moon conspiracy theorists, they postulate a massive conspiracy required to pull it off, yet, they likewise postulate sophomoric "errors" that reveal to the theorists that it was a plot.

TTFN

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RE: WTC Bldg #7

Let me say this, its not a secret if more than one person knows about it. For it to be a controlled demo, more than one person had to be in on it.  

RE: WTC Bldg #7

The interesting thing for me is the psychology of the believers: any evidence that tends to disprove the theory is taken to be evidence that the plot was even more devious than originally thought.

Michael.
Timing has a lot to do with the outcome of a rain dance.

RE: WTC Bldg #7

Well, you would be surprised to read at some website (as I read once) that even the 2 WTC towers had built-in demolition charges at construction time; I think to remember it was second hand testimony as told to the writer of such item by someone that purportedly was himself in such works.

It is the duty of citizens to watch on their governments, democratic or not, for if of course the general intent of governments may be overally sounder for the many, it can be exterminating for some, ane everyone can be one of such "some".

The pressure to know the truth of the matters that affect the general public must be always be kept ongoing, and it is extremely unfortunate that most of the more enabled to so provide remain too silent at critical times.

RE: WTC Bldg #7

There is no way jet fuel will burn hot enough to take down a building like that. It had to be the government.

Then again the planes had just taken off and they were still loaded with the con-trail mind control chemicals. and who knows how hot that stuff burns!

RE: WTC Bldg #7

That's a good one Ishvaaag-

How would the conversation go:
Let's see- we are over budget during construction, what can we cut? Perhaps the explosive charges on the columns? No, we better keep that one in case we need to blow up the building in 25 years.   


I had some conspiracy theories of my own from other events in the past. My brother-in-law set me straight when he pointed out that for these conspiracy theories to work, we had to assume that the government was competent and could keep a secret. After realizing the ludicracy of that- I gave up on conspiracy theories.
 

RE: WTC Bldg #7

It just has to be hot enough to change the properties of the steel, reducing the yield point and modulus of elasticity.

Regards,
Qshake
pipe
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
 

RE: WTC Bldg #7

"There is no way jet fuel will burn hot enough to take down a building like that."

What I heard was that the impact of the planes knocked the fire protection off enough of the structural steel for the fire to weaken that section of the building.

As for conspiracy theories, I think the government/media ability to spin the information, about something this big that others did, for their own benefit is the most they could do.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

RE: WTC Bldg #7

hawkaz, considering the things humans have made in the past, just dismiss that preinstalled demolition charges might not have been placed there, and in many more buildings in the world, is to think of humans as far less innocent than they are.

Of course proof is another thing, and nor it is my task nor my intent to assert anything beyond my means of proof, but considering the options may help in finding the truth when one is searching for it.  

RE: WTC Bldg #7

2
Regarding the collapse of the towers...
Most of the jet fuel was burned in the large fire ball explosions that occured shortly after impact.  The remaining fuel (thousands of gallons) was released into the core of the building and substructure through the elevator and stair shafts.  The investigation found that the impact of the large 747 airplanes, knocked off much of the fire proofing.  This greatly reduced the fire rating.  At the time of design, Mr Robertson had considered the impact of a Boeing 707, the largest aircraft in production.  This additional consideration was made after a small aircraft hit the Empire State Building.  However, this consideration had little impact on the design due to the high wind forces already considered on New York highrises.  The actual impact speed was nearly 1.5x greater than the estimates of the 707.  There was also no specification for the adhesion of fireproofing to the structural steel.  The primary consideration was to provided adequate thickness for the necessary fire rating.  In addition to the highrise structures there is nearly 7 stories of underground structure.  Built before significant use of rebar, many of these concrete walls are more than 7 feet thick.  This made these levels a furnace.  During a visit in October 2001, they were still removing red hot sections of steel structure from these sublevels.  

Building 7 did not suffer a direct impact, but was simply allowed to burn.  

WTC 7 was rebuilt relatively quickly after the collapse.  The new structure has studs on all surfaces of the structural columns to provide additional surface area for the fire proofing.  The structure is also designed for significant impact forces and progressive collapse.  After the collapses it was determined that redistribution of forces in other damaged buildings exceeded the performance expectations.  However, nearly every girder to column connection in WTC 7 is designed for potential of lost columns and significant load redistribution.      

My point is...  We work with the data available at the time.  There is no conspiracy in these collapses.  We waste resources looking for improbable solutions.  Although not the intent of the designers, the designs performed amazingly in their failure.  The additional devastation would have grown exponentially had any of these structures fallen laterally, in the direction of other structures or survivors.  Sometimes these things require a little luck or devine intervention.  But searching for a conspiracy is simply a waste.  This energy would be better spent improving our designs and understanding how to better control our structures in a disaster.       

http://www.FerrellEngineering.com

RE: WTC Bldg #7

the great thing about conspiracy theories is that you can't prove (or disprove) them

RE: WTC Bldg #7

"we had to assume that the government was competent and could keep a secret"

How true.

Having Ed Asner as the narrator should have been the first sign that this is bogus.

RE: WTC Bldg #7

You must believe MainMan10 for he is a licensed SE :)

RE: WTC Bldg #7

"Having Ed Asner as the narrator should have been the first sign that this is bogus"

Let's not forget the involvement of Pierre Salinger in the TWA Flight 800 conspiracy theory.  Ed Asner only played a reporter.  Salinger was an actual reporter, and someone steeped in government operation.

Interestingly, the video never compares WTC1's and 2's collapses, which, to me, seemed eerily like intentional demos as well.

TTFN

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RE: WTC Bldg #7

"Well, you would be surprised to read at some website (as I read once) that even the 2 WTC towers had built-in demolition charges at construction time; I think to remember it was second hand testimony as told to the writer of such item by someone that purportedly was himself in such works."

@ishvaaag, This also would have been highly visible to the many construction workers.

Michael.
Timing has a lot to do with the outcome of a rain dance.

RE: WTC Bldg #7


IRStuff - it sounds like you're changing your position?

There was an analysis of the collapse of WTC 1 and 2 performed by a prominent SE firm for the leaseholder (Silverstein). They filed a lawsuit against their insurer. The insurer said the collapse was one incident whereas Silverstein said it was two discrete incidents, hence twice the settlement. Silverstein won the case based upon the analysis.

Silverstein's engineers had to demonstrate how the impact of the planes resulted in collapse. If it were CD it would have been discovered in court.  

RE: WTC Bldg #7

Wizard's First Rule: "People are stupid and believe what they want to believe".  No amount of proof and rational argument can sway the true-believer.

RE: WTC Bldg #7

Right, and Apollo never made it to the moon winky smile  Merely pointing out that looks can be deceiving.  

As for explosives built-in?  Right, 30-yr old explosives working to spec?  And wired up to explode for 30 years?  Who in their right, or wrong, mind would even contemplate leaving live explosives in a building?  No worries about accidential detonations?  No worries about even finding the detonator after 30 yrs?  Umptydump people keeping the secret for 30 yrs?

TTFN

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Chinese prisoner wins Nobel Peace Prize

RE: WTC Bldg #7

I wonder why some folks think an intentional and unintentional demolition should differ.  Gravity is the same in each, and the direction is always downward.  The steel lost strength due to burning fuel load, most of which was already in the building.  The fact that the second building to be hit collapsed first because it was struck lower down just confirms that the loss of strength in the vertical support system made them fall.  One correction to connectegr's excellent post...the planes were 767's, not 747's, but still much heavier than a 707.   

RE: WTC Bldg #7

BA..good post...lots of interesting discussion.  Thanks.  Proves that most of us (engineers) are logical thinkers and don't subscribe to illogical crap that gets thrown at the world by the technically unwashed.

RE: WTC Bldg #7

It also indicates the tremendous complexities which arise when a high rise building is partially constructed, then the top part changes significantly.  Having been involved in a couple of those, I cringe at the thought.

RE: WTC Bldg #7

Its too bad the crazy architects that lead us down those silly paths at times do not read this and at least try to understand the complexities.  I just finished a project where I had to move columns around desks.  That was the first time in my career, and I don't know when I may get over that.

Brad

RE: WTC Bldg #7

(OP)
Thanks for the input, guys.  I think you have put the issue in perspective.

BA

RE: WTC Bldg #7

Quote:

Its too bad the crazy architects that lead us down those silly paths at times do not read this and at least try to understand the complexities.  I just finished a project where I had to move columns around desks.

I'm always ready to pile on the blame on the artists, but in this case wouldn't the bolded part suggest it was the interior designers whose 'vision' was supreme and unalterable?

Someone get the smelling salts for Brad805, quick...



Lesson Learned: Engineers, know your place!
 

RE: WTC Bldg #7

As I said, I don't subscribe to any particular conspiracy theory about 9/11 but you can swear that there are lots of things that can make any rational mind to raise a brow, if only to arrange the facts for consideration. But of course there are as well many that don't want to look at all at such things. I understand that certainly our particular abilities are better employed in things we are more proficient than perusing funny writings about things, but I have never felt comfy on just being a tool for someone getting his purpose. I mean, happy new world á la Huxley is not for me the correct proposition for the place of people in the world, and I think education should enable all us to look well beyond our core practical activities. The ongoing crisis has many people far-off the core of reason saying appalling truths, this reminds me the joke of the fool seated at the wall of the insane asylum saying to someone (after giving sound advice to him): Well, we those here are tha mad, not the stupids!  

RE: WTC Bldg #7

Quote:

Well, you would be surprised to read at some website (as I read once) that even the 2 WTC towers had built-in demolition charges at construction time; I think to remember it was second hand testimony as told to the writer of such item by someone that purportedly was himself in such works.

Pshaw...get with the times daddio!

Mini-nukes in the basement is where it's at. Or, as in another theory, conventional explosives were used to supplement the destruction, because you know those darn mini-nukes just didn't have enough oomph on their own.

Sometimes if you didn't laugh you'd cry.

RE: WTC Bldg #7

As I said, I don't believe the story -I am not a "believer", understand it as you are willing to- just brought it to discussion. You may laugh whathever you want, so anyone can.

There are many unknowns and unbelievable things en 9/11 matters -and not only in the conspiracy side- at least from the public viewpoint, and there are lots of people not wanting such things well established and known.

I have no particular interest in such established truths whatever their final clarity and stance, I have clear what of political activities can be expected as pertaining to truth, since interest overrides it every time they deem necessary so.

But to make gullible of those that are not, even within their imperfect knowledge, does not seem to me precisely a convenient proposition from a rational viewpoint.

RE: WTC Bldg #7

I found it interesting that the metallurgical "experts" interviewed in the clip fixated on the existence of microscopic spheres of iron as proof of the thermite conspiracy. As a real metallurgist, I have seen many cases of microscopic iron spheres showing up as extraneous debris due to torch cutting of large samples to get them down to lab workable size. So, it shouldn't surprise any one that iron particle debris was found, given that lots of torch cutting (and probably the use of Thermite cutting rods)undoubtedly went on during the recovery of survivors and the later body retrieval on Towers 1 and 2.

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