NIST Officially Admits Freefall Speed re:WTC 7!!, page 9
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reply posted on 17-12-2008 @ 08:38 PM by VitriolAndAngst
Originally posted by ahnggk
Originally posted by mbkennel
Only if all of the mass building was moving at free fall. In reality, you see some of it (the upper parts) doing so, but that doesn't mean that all of it did, and for all time from initial to final configuration.

Collapsing buildings fall at 'g', whether from internal collapse or induced collapse.

This is not indication of any conspiracy at all


I'm an engineer and I agree with this. When the upper floors collapsed, the huge mass falling down, there's no artificial structure on earth absorbing such force. If you try to even absorb energy of the falling mass' for a couple seconds to a full stop, that would amount to dozens of G's(G-forces so to speak).

I don't know how heavy the upper floors that fell, probably, thousands of tons or more, multiply by the dozens and you have an enormous unstoppable force.

ALTHOUGH it is still plausible they used explosives to maybe contain the collapse and minimize damage to surrounding buildings. But with explosive or not, the speed of collapse would not have significantly be affected.


Of course the lower floors have adequate resistance. At least 4 to 5 times the weight of the entire building. An Engineer would know that most structures are built to withstand 2 times the weight of the structure. WTC was designed to hold even more.

In a collapsing building, not all of the weight would bear down immediately. At "free fall speed" you are saying there is NO resistance -- which makes NO sense. I'd read some engineer calculations that a Pancake Collapse of the WTC would take at least 60 seconds if not up to 90 seconds.

I thin that the angle-cut steel beams that we can see in the aftermath photos, are even more evidence of shaped charges or actual cuts in the supports. Steal doesn't "snap" or break at an angle -- you would get bending at the stress points first.


reply posted on 22-12-2008 @ 05:04 AM by Anonymous ATS
reply to post by ashamedamerican



The Citycorp building!

"Changes during construction led to a finished product that was structurally unsound. In 1978, prompted by a question from a student, LeMessurier discovered a potentially fatal flaw in the building's construction: the skyscraper's bolted joints were too weak to withstand 70-mile-per-hour (113 km/h) wind gusts at specific angles.

"While LeMessurier's original design and load calculations for the special, uniquely-designed 'chevron' load braces used to support the building were based on welded joints, a labor and cost-saving change altered the joints to bolted construction after the building's plans were approved.

"For the next three months, a construction crew welded two-inch-thick steel plates over each of the skyscraper's 200 bolted joints during the night, after each work day, almost unknown to the general public."


reply posted on 11-3-2009 @ 05:22 PM by bloodWolf762
reply to post by Anonymous ATS



The most important thing besides Giuliani's emergency command center, the CIA and FBI field offices, among other private and other government offices in WTC 7 was the Securities and Exchange Commission (SEC) offices.
SEC is an independent agency of the United States government which holds primary responsibility for enforcing the federal securities laws and regulating the securities industry, the nation's stock and options exchanges, and other electronic securities markets. Think WorldCom and Enron. Numerous hard copies of investigations and evidence into corporate crime were in Building 7 when it went down.


reply posted on 16-3-2009 @ 08:38 AM by Achorwrath
Just an FYI to to demo a 32 Story building requires (depending on the support structure) Upwards of 4,000 charges and over 30,000 feet of detcord. Each charge has to be timed and calculated they have to be carefully placed to damge the proper portions of the beams.

WTC 7 had a unique support structure, its supporting colums did not extend to the full extent of the building.

WTC7 was originally designed to be smaller, when they enlarged the build during construction they extended support out from the central colums instead of widening the colum base.

Unfortunately when you do this you do create a weak structure.

In a controlled demolition of a building you want to time the destruction of supporting colums from the bottom up.
Meaning you start with the bottom floors and move upward, you want to remove each floor in succession. so they drop down on each other.

What happened with WTC 1,2, and 7 was a weakening of the buildings due to impact damage (WTC 1 and 2 lost strucural integreity across 8-10 floors with the impact) WTC 1 and 2 were built with external curtain support (to help control lateral sway) and a central core. The planes not only took out the curtain support but the at least 2 floor slabs. the central cores were damaged (as cooborated by people that made it out). This puts the building in a "non-pristine" state.

Even the original designer admit they expected an airplane to have a "pencil though a scree" effect and not the drastic damage that actually happened.

But once the damaged, weakened and exposed steel was heated to at least 600f (JP5 burns at 495.5F in open air with no accelerants yet there were plenty of accelerants which is why some aircraft fires can reach 3000F)

collapse was inevitable, with upwards of 54,000 tons (floors 93 to 110) dropping down on top of it the reast of the building could not hold up.

WTC7 did recieve imapct damage and was known to be on fire, fire and impact damage considerations for WTC were NOT as high as for WTC 1 and 2. There was not consideration for impace damage to the top or side of the building.

due to a poor design the support structure for the whole building could be comprmised by the loss of one support column. Again the desgin was not made to account for impact to the sides, or top.

Fire only assited in WTC7s demise.

Edited for typographical errors.

[edit on 16-3-2009 by Achorwrath]


reply posted on 16-3-2009 @ 10:08 AM by Griff
Originally posted by Achorwrath
Just an FYI to to demo a 32 Story building requires (depending on the support structure) Upwards of 4,000 charges and over 30,000 feet of detcord. Each charge has to be timed and calculated they have to be carefully placed to damge the proper portions of the beams.


And can you explain why exactly this is necessary?

I can:

To make sure the building doesn't topple. But, yet, a 47 story building just falls into itself due to fire?

WTC 7 had a unique support structure, its supporting colums did not extend to the full extent of the building.

WTC7 was originally designed to be smaller, when they enlarged the build during construction they extended support out from the central colums instead of widening the colum base.


So, it's the architects and engineers fault that this building fell due to fire? What happened to proper design? What happened to fire codes?

Oh, that's right, when your name is Silverstein and Rockefeller, [sarcasm]you don't need no stinking codes.[/sarcasm]

Unfortunately when you do this you do create a weak structure.


According to Silverstein, this structure was so robust that it could "have portions of entire floors" removed and still stand.

BEFORE it moves into a new office tower in downtown Manhattan, Salomon Brothers, the brokerage firm, intends to spend nearly two years and more than $200 million cutting out floors, adding elevators, reinforcing steel girders, upgrading power supplies and making other improvements in its million square feet of space.

''We built in enough redundancy to allow entire portions of floors to be removed without affecting the building's structural integrity, on the assumption that someone might need double-height floors,'' said Larry Silverstein, president of the company. ''Sure enough, Salomon had that need.


query.nytimes.com...

But once the damaged, weakened and exposed steel was heated to at least 600f (JP5 burns at 495.5F in open air with no accelerants yet there were plenty of accelerants which is why some aircraft fires can reach 3000F)


First, the magic number is 600C not 600F. Big difference.

Second, can you site evidence that the steel reached this temperature?

collapse was inevitable, with upwards of 54,000 tons (floors 93 to 110) dropping down on top of it the reast of the building could not hold up.


I just love the argument that "collapse was inevitable". It makes me chuckle every time I hear it.

due to a poor design the support structure for the whole building could be comprmised by the loss of one support column. Again the desgin was not made to account for impact to the sides, or top.


NIST states that the impact had very little to do with the collapse. Try again.

Fire only assited in WTC7s demise.


Not according to NIST.

NIST WTC 7 Investigation Finds Building Fires Caused Collapse


www.nist.gov...


reply posted on 16-3-2009 @ 11:04 AM by PplVSNWO
reply to post by Achorwrath


Now that is some doublethink there. We are to believe that it would have taken 4,000 charges to demo WTC7, yet according to NIST the whole building came down the way it did with the failure of a single column. Then you claim that WTC7 received impact damage, but NIST's report says neither the generator fuel nor impact damage were a factor in the collapse. The graphical evidence debunks the impact damage anyway, the photos only show some facade damage, not structural.


reply posted on 16-3-2009 @ 11:26 AM by Achorwrath
Steel weakens

According to this article and others on the rigidity of steel steel begins to weaken at 230C now 600F is 315.5C well above the needed 230C

But lets consider that the open air burning temperature of JP5 is 549.5F ( made a typo earlier my mistake

However, since very few comercial airliners use JP5 lets take a look at the less refinded J-A1 this has an Open Air burning temperature of 287.5c (549.5F) even at this temperature it is well above the weakening point of steel.

You confuse melting with weakening.

and as with many others you do not take into account the MASSIVE damage done to the building (WTC 1 and 2).

Removing floor beams is not the same as removing a support colum.

I love how you guys like t use the NIST paper to support you own arguments and then call it trash to disprove the "official story".

I never said the NIST report claimed damage.

I said there was damage to the top and side of the structure that is from reading the many accounts and documents (other than the NIST one).

I am not quoting the NIST report in any of my posts nor referencing it in any (other than here).

here is my link to the reasons behind the use of that many charges and that much detcord.

This is directly from the work log of a company that demos buildings.

note over 4,000 charges and 36,000 feet of detcord used.
this is due the the issue of having the charges linked to explode in a very controlled series and this is for a 32 story building.

Yes WTC had a flaw that was overlooked, like many of the recalls that happen every day because someone in a position authority during the construction thought it would not be a concern.

Things like this happen all the time in construction and in contract building.

[edited for clarity and to add addtional source information]

[edit on 16-3-2009 by Achorwrath]


reply posted on 16-3-2009 @ 01:47 PM by Griff
Originally posted by Achorwrath
Steel weakens

According to this article and others on the rigidity of steel steel begins to weaken at 230C now 600F is 315.5C well above the needed 230C

But lets consider that the open air burning temperature of JP5 is 549.5F ( made a typo earlier my mistake

However, since very few comercial airliners use JP5 lets take a look at the less refinded J-A1 this has an Open Air burning temperature of 287.5c (549.5F) even at this temperature it is well above the weakening point of steel.


Steel weakens to 50% at around 600-650C. It does not "severly weaken" at 230C like that link would have us believe.

Since buildings have a greater factor of safety than 2.5, then how do you explain this massive loss of structural integrity all at once?

Especially when we learn that NO steel was recorded to have a temperature greater than 250C (unless you want to site the pieces that went to 650C....but these pieces reached that temperature in the debris piles.

Maybe you should start reading NIST if you are going to bash them? Because a lot of their information is correct. Just the way they put it all together is incorrect IMO.

You confuse melting with weakening.


Sorry, but no I am not.

and as with many others you do not take into account the MASSIVE damage done to the building (WTC 1 and 2).


You mean the massive damage that affected less than 15% of the columns?

[edit on 3/16/2009 by Griff]



reply posted on 16-3-2009 @ 02:24 PM by Achorwrath
Originally posted by Griff
Originally posted by Achorwrath
Steel weakens

According to this article and others on the rigidity of steel steel begins to weaken at 230C now 600F is 315.5C well above the needed 230C

But lets consider that the open air burning temperature of JP5 is 549.5F ( made a typo earlier my mistake

However, since very few comercial airliners use JP5 lets take a look at the less refinded J-A1 this has an Open Air burning temperature of 287.5c (549.5F) even at this temperature it is well above the weakening point of steel.


Steel weakens to 50% at around 600-650C. It does not "severly weaken" at 230C like that link would have us believe.

Since buildings have a greater factor of safety than 2.5, then how do you explain this massive loss of structural integrity all at once?

Especially when we learn that NO steel was recorded to have a temperature greater than 250C (unless you want to site the pieces that went to 650C....but these pieces reached that temperature in the debris piles.

Maybe you should start reading NIST if you are going to bash them? Because a lot of their information is correct. Just the way they put it all together is incorrect IMO.

You confuse melting with weakening.


Sorry, but no I am not.

and as with many others you do not take into account the MASSIVE damage done to the building (WTC 1 and 2).


You mean the massive damage that affected less than 15% of the columns?

[edit on 3/16/2009 by Griff]


15% based on what?
Where did you get this information can you show me? The tower lost 8 floors ( 93 to 101) worth of integrity on one side the side that feel first. from the curtain wall to at least the core steel beams.

Now you have stated that you are a structural engineer (or at least working on being one) what does this type of support loss mean to you?

You should know that the loss of that much of the support system (remember the outer curtain wall (later sway control) is supported by the floor beams conncting from the outer wall to the inner core supports.

Now you have up to 8 floors that are compromised along a single axis of support.

You are making an assumption about the type of steel used, typically steel used in construction has only 2.1% carbon meaning that its solidus point is 1130. Steal looses 50% strength at 1/2 its solidus point; this case 565C

But can loose as much as 30% stregnth with as little at 350C.

Please remember that airplane fires have been logged at temperatures of up to 3000F due to the burning of accelerants and the metal of the aircraft.

How were the temperatures of the metal tested can you link that? I have not read any type of thermographic testing of the steel in the building
prior to collapse.

I think the biggest thing that is overlooked is the damage to the building, it is not a typical building it was built with a central core and an outer colum support for sway they then tied the floor beams into the outer colums to add support to them. Once that support was damaged it weakened the whole building.
.


reply posted on 16-3-2009 @ 02:53 PM by WonderwomanUSA
reply to post by Achorwrath



The NIST report was put out too fast with not engouh time to properly cover the issue.


Yes, it was, seven years to fast

The people involved did not check their facts and ther conclusions.


You are right about that! They where to busy covering up the truth, and falsifying the evidence.

There was too much left out that people saw and heard
.

I disagree, NIST left out the truth, on everything they where paid to “avoid” doing the real study on demolition which is what brought all three WTC down. When will Americas WAKE UP! And pull their heads out of the sand.

This is proof, of NIST just ball face lying or, they are just to incompetent to do the study

9/11 Nano-thermite composite Demolition Evidence

www.youtube.com...

Prosecute the NIST for Obstruction of Justice


existentialistcowboy.blogspot.com...
Nothing but proof of what liars NIST are, and how they sold out to political pressure, from the Bush administration.





[edit on 16-3-2009 by WonderwomanUSA]


reply posted on 16-3-2009 @ 03:40 PM by Griff
Originally posted by Achorwrath
15% based on what?


Actual observation.

Where did you get this information can you show me?


NIST

The tower lost 8 floors ( 93 to 101) worth of integrity on one side the side that feel first. from the curtain wall to at least the core steel beams.


First, you question where I get an observable fact, then you go on and tell me something non-observable?

Second, they did not start failing on the sides that were hit. Look at the tilt of tower 2. It is tilting AWAY from the side that was hit.

Now you have stated that you are a structural engineer (or at least working on being one) what does this type of support loss mean to you?


It means the towers would stand. As they did.

You should know that the loss of that much of the support system (remember the outer curtain wall (later sway control) is supported by the floor beams conncting from the outer wall to the inner core supports.


Can you show how 8 floors worth of support loss to less than 8% of the building causes "massive" damage and collapse?

Now you have up to 8 floors that are compromised along a single axis of support.


Was it the weak or strong axis?

You are making an assumption about the type of steel used,


No, I'm not. It was A-36 construction steel for the columns.

typically steel used in construction has only 2.1% carbon meaning that its solidus point is 1130. Steal looses 50% strength at 1/2 its solidus point; this case 565C


Well, now that your site has been called out as incorrectly saying that a major loss of integrity happens at 300C, you move the goal posts.

Just remember that for the official story to be true, the steel would have to reach over 600C not the fire temperature.

Can you point to the evidence that this happened?

But can loose as much as 30% stregnth with as little at 350C.


Can you site this information? And is 30% strength loss significant with a FOS greater than 2.5?

Please remember that airplane fires have been logged at temperatures of up to 3000F due to the burning of accelerants and the metal of the aircraft.


Temperature of fire and temperature of steel in a fire are 2 totally different things.

How were the temperatures of the metal tested can you link that?


NIST.

I think the biggest thing that is overlooked is the damage to the building, it is not a typical building it was built with a central core and an outer colum support for sway they then tied the floor beams into the outer colums to add support to them. Once that support was damaged it weakened the whole building.


And what happened to the lateral support within the core itself?

[edit on 3/16/2009 by Griff]
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