John Groos NIST engineer admits fire dont melt steel...

Jet fuel can burn at 980C/1796F and when you add the combustible materials inside the building, the temps would cause more than 50 percent reduction in strength, not to mention the expansion and contraction that would cause the concrete around the steel to crack. You also have to factor in the impact damage.

www.popularmechanics.com...

"Steel loses about 50 percent of its strength at 1100°F," notes senior engineer Farid Alfawak-hiri of the American Institute of Steel Construction. "And at 1800° it is probably at less than 10 percent." NIST also believes that a great deal of the spray-on fireproofing insulation was likely knocked off the steel beams that were in the path of the crashing jets, leaving the metal more vulnerable to the heat.

But jet fuel wasn't the only thing burning, notes Forman Williams, a professor of engineering at the University of California, San Diego, and one of seven structural engineers and fire experts that PM consulted. He says that while the jet fuel was the catalyst for the WTC fires, the resulting inferno was intensified by the combustible material inside the buildings, including rugs, curtains, furniture and paper. NIST reports that pockets of fire hit 1832°F."



[edit on 2-3-2007 by BlueRaja]

Jet fuel can only sustain those temperatures in a controlled burn, IE being fed the right amount of oxygen.

There is also the brief phenomena known as flash over, like when the planes first crashed and the huge fireballs went flying out the side.

During flash over, the jet fuel is a mist that effectively mixes with air and can burn hotter. Flash-over only last a few seconds at most.

Open air puddles of jet fuel in uncontrolled burns, like almost all combustibles, burns at around 550C.

All of the carpeting, walls, furniture, etc HAD to meet strict building fire codes. They were flame retardant.

A 200:1 safety ratio structure loosing 50% of its strength still has 100:1 safety factor, only loaded to 1% of its max capacity.

If you have sources otherwise, by all means...

NIST reports that pockets of fire hit 1832°F

Based upon their controlled burn super sprayers that generated 3.5MW of power. The NIST's own report states that the core columns did not see temperatures above 250C.

[edit on 3/2/2007 by sp00n1]

Originally posted by CameronFox
I suggest YOU do some research as well. NIST never claimed that steel was melted. NIST actually stated that the collapse was initiated for 3 reasons.
1- Severe damage to a building due to an airliner flying into it
2- Fires
3- The removal of fire proofing material casued my plane impact

Removing any one of the three could possibly result in the building not collapsing. ie: fire alone ..fireproofing surviving impact. etc.

Ok, lets remove 1, and 3, and then ask why the hell WTC 7 collapsed.

Originally posted by sp00n1
The computer models also modeled estimated damage, as well as a number of very mysterious variables which NIST refuses to disclose, even though it is critical to their 'animation'.

That alone is enough for a new investigation. At BEST, that is horrible, horrible sloppiness for any professional. That's at best. I think it would take more than that for someone to run an intricate simulation, and then not publish the full parameters. That's too stupid to have been unintentional. It invalidates everything they did with that simulation. They might as well not even have mentioned it in their report, and it would have made them look better (the simulations didn't produce failures anyway).

[edit on 2-3-2007 by bsbray11]

Originally posted by CameronFox
I suggest YOU do some research as well. NIST never claimed that steel was melted. NIST actually stated that the collapse was initiated for 3 reasons.
1- Severe damage to a building due to an airliner flying into it
2- Fires
3- The removal of fire proofing material casued my plane impact

Removing any one of the three could possibly result in the building not collapsing. ie: fire alone ..fireproofing surviving impact. etc.

Actually, somewhere in the NIST report is a statement saying that if not for the fireproofing being knocked off (which they never logically established, LOL), the team doubted the buildings would have collapsed, because the plane impacts caused only relatively minor damage to the global structures because of their robustness, and if you've actually read even portions of the NIST report, then the reason fire shouldn't have *otherwise* caused collapses is obvious: they proved in their labs what the Cardington tests established years ago, and that's that fires does not cause run-away collapses in steel structures.

So it all falls back on the assumption that the fireproofing was all knocked off, AND that unfireproofed steel can initiate a run-away collapse when sufficiently heated. NIST disproved their own second assumption as noted above, but the fireproofing test was conducting by shooting a shotgun at a column with spray-on fireproofing. I couldn't make this stuff up.

by the way...


...it doesn't matter how hot the fire gets, it matters how hot and concentrated the heat of the fire gets on the steel. Steel conducts heat, and spreads it around. Just like a heat sink on a computer processor, the heat will spread across the metal surface's of the heat sink, and allow the processor to stay more cool. The WTC buildings were like giant heat sinks. Even if you heated up one spot of a steel beam, that heat would want to spread throughout the entire building. The more surface area for air to contact the steel, the more cool the steel will stay. So the building is constantly cooling down, faster than it is heating up.

So even if you purposely tried to heat a part of the steel to a certain temp, it would take quite a while because the heat would want to transfer to the rest of the building first. So to get a piece of steel to 1800, to loose its strength like it "did" on 911, you would need a concentrated fire about twice that temperature.


Also, fire proofing getting knocked off do to an impact is a complete lie. I was at a new steel building construction site the other day and I saw some of the same fire proofing they used in WTC, and you know what? There was no way a brute force impact could knock that stuff off. You have to really scrape that stuff.


[edit on 2-3-2007 by Connected]

Fact of the matter is that there is something called a theory of resistance which would have made the collapse of 1 & 2 much slower if indeed "Fire" was the only energy force used that day.

Come on people this is pretty much common sense!! Look at the pictures and or video of the collapses. Fire does not have the energy to throw giant steel beams outward and pulverize concrete!!! Look at the video and ask yourself can fire really do this??

I have a Steel grate in my fireplace and buring a very hot fire on it almost every night for hours on end, and it doesn't melt. Buildings should not be able to fall at Free Fall Speed from fire alone!! Remember there was plenty of floors below the impact that were untouched by fire, that would cause a serious amount of resistance even if the top began to fall, which would slow down the collapse considerably

Originally posted by thematrix
Even if that were so, only where there was fire the steel would have been weakend to the point of loosing loadbearing capability, it doesn't explain at all how the building collapsed as if there was no steel or even concrete in the building at all.

It came down way to fast for that and the entire structure disintegrated and came down in a time period and at a speed CD specialists would be jealous about.

No, the building came down at the speed that all buildings come down, nearly free fall.

When you lose structural integrity, it usually happens at the bottom because that's where the load is the greatest, because it's holding up the most weight. Once that goes, the whole building starts accelerating downward at -g with little to stop it.

Here is what happens. Plane hits WTC. Fires burn in the middle, weaking steel there. When structrual members there get hot enough and fail, then the building above the hole slams into the building below the hole.

This transmits a huge dynamic, transient force (the weight of the upper stories falling down striking the rest of the building, ow!) down the structural members below the hole at the speed of sound in concrete & steel, which is very high.

This massive overforce blows out the structural integrity all along the bottom of the building below the hole, especially near the bottom where it is heaviest.
(this is what you see in the films of the 'outgoing' spiffs of debris right before the main collapse, it is the wave of overload destroying the intermediary members.)

Now, there is nothing holding up the structure anywhere, and like a waterfall of concrete, it falls down nearly as a whole (like controlled demolition).

The problem is that too many people think of "movie physics" when they see blowing up buildings (e.g. Die Hard and the rest), with violent outward explosions. Movies are made to look dramatic.

That's not what happens in real life. The salient physics of buildings are that they are very very heavy, and they want to go straight down. Buildings collapse down, that's it.

Controlled demolition and uncontrolled demolition look fairly similar if you blow out the structural elements, because the physics is the same.

Tests years ago at Cardington in the UK have clearly show that it takes 7-8 hours to cause steel with aviation fuel CONTINUOUSLY SPRAYED ON IT to loose its structural integrity.

Originally posted by CameronFox
I suggest YOU do some research as well. NIST never claimed that steel was melted. NIST actually stated that the collapse was initiated for 3 reasons.
1- Severe damage to a building due to an airliner flying into it
2- Fires
3- The removal of fire proofing material casued my plane impact

Removing any one of the three could possibly result in the building not collapsing. ie: fire alone ..fireproofing surviving impact. etc.

Thing is the NIST and FEMA reports stated the planes impacts had no effect on the building, it would have stood all day. Thier had to other things effecting the building.

When you lose structural integrity, it usually happens at the bottom because that's where the load is the greatest, because it's holding up the most weight. Once that goes, the whole building starts accelerating downward at -g with little to stop it.

Tssk tssk. Once again, a very weak statement made in an attempt to justify murder.

If the 'base' had weakened first and then surrendered due to the load then the buildings would have toppled instead of collapsed. Plus, they would have started to collapse at the bottom instead of from the top downward. Plus, what was at the bottom to weaken the base? No fires. Nothing. The fires were 800 plus feet above.

I am not trying to go on the attack here. I just don't like it when someone comes up with an argument that, with some logical thought processes put into, holds no water.

Is it really that hard to think the Gov't lied about 9/11. They lied about the reasons going into Iraq.

One has to assume if they lie about taking a country to war its not a large leap to think they would lie about attacking their own citizens.

History has shown us that many countries have used "false flag" operations to achieve something, why do people think this current Gov't wouldn't stoop to the same level?

Originally posted by Reap
I think you'll find that steel loses 2 thirds of its tensile strength at about 500 c more that enough to cause collape also when steel RSJ's heat up they expand pushing out walls and supports

The problem is how did the heat from a few fires, on just a few floors, heat ALL the steel up to 500c?

It's not as simple as you seem to think. The columns would have acted like heat syncs, taking the heat from the part being heated and spreading it along the whole length of the columns, thus cooling it.
Also the temps the fires reached would not be enough to heat the steel to 500c in less than an hour anyway, even if the whole building was engulfed.

To heat steel to the point of weakening it needs a very hot direct heat.
Go do some forging, and you'll see how silly the idea is that office fires weakened 47 massive steel columns.

Simple physics.

video.google.co.uk...

Go to like 24 seconds into that video, when the camera moves to the left and then
up to record the "collapse" you can clearly see there is a lot of smoke at the base
of the WTC there.
Also at 2min19s.

Just to emphesize a bit that something happened there which caused a lot of
smoke to emerge from the base. And, take my word for it, it wasnt a plane

Anyway, go watch him "explain" the towers collapse again and again and again,
eventually you will notice all he brags about is "collapse initiation" and
"unstoppable mass" plus no further calculations needed.
The question is not if the "collapse" initiated, its obvious the building "collapsed",
the question is HOW and WHY did it initiate... He just goes on that after "collapse
initating" it was unstoppable and no further calulations were needed.

LOL?

And also, the blueprints of the exact building design and stuff are not for public viewing...
Why? : Because that would beyond any doubt prove the buildings should not have "collapsed".

[edit] oh and that be blatantly DENIES molten metal/steel exists, what a f* joke LOL

[edit on 3-3-2007 by zren]

If the blueprints were public we would also be able to determine how extreem they "tweaked the parameters" in their computer simulations, to get it to initiate collapse.

Its admitted that neither their real world test or computer simulations gave any results near what happend (heck, they didn't even get it to budge that way), so they "tweaked" the parameters in the simulation software untill they did get a collapse initiation.

And as discussed before in the thread, they don't publish any data further then that.
Even those tweaked parameters probably didn't have the building actualy collapse like it did.

[edit on 3/3/07 by thematrix]

In their tweaked models, they really have some amazing results. They barely got their model 'on the verge of collapse' then stopped the simulation. Their 'collapse' looked nothing like what we saw on 911. It was not rapid, symmetrical, or complete.

They refuse to show their collapse simulation.. i wonder why;

An article in the journal New Civil Engineering (NCE) lends support to concerns about
the NIST analysis of the WTC collapses. It states:

World Trade Center disaster investigators [at NIST] are refusing to show
computer visualizations of the collapse of the Twin Towers despite calls from
leading structural and fire engineers, NCE has learned. Visualisations of collapse
mechanisms are routinely used to validate the type of finite element analysis model
used by the [NIST] investigators. The collapse mechanism and the role played by the
hat truss at the top of the tower has been the focus of debate since the US National
Institute of Standards & Technology (NIST) published its findings….
University of Manchester [U.K.] professor of structural engineering Colin Bailey said
there was a lot to be gained from visualising the structural response. “NIST should
really show the visualisations; otherwise the opportunity to correlate them back to
the video evidence and identify any errors in the modeling will be lost,” he said….
A leading US structural engineer said NIST had obviously devoted enormous
resources to the development of the impact and fire models. “By comparison the global
structural model is not as sophisticated,” he said. “The software used [by NIST] has
been pushed to new limits, and there have been a lot of simplifications,
extrapolations and judgment calls.” (Parker, 2005; emphasis added.)

The Investigation Team then defined three cases for each building by combining the middle,
less severe, and more severe values of the influential variables. Upon a preliminary examination
of the middle cases, it became clear that the towers would likely remain standing. The less
severe cases were discarded after the aircraft impact results were compared to observed events.
The middle cases (which became Case A for WTC 1 and Case C for WTC 2) were discarded after
the structural response analysis of major subsystems were compared to observed events. (NIST,
2005, p. 142; emphasis added.)

The more severe case (which became Case B for WTC 1 and Case D for WTC 2) was
used for the global analysis of each tower. Complete sets of simulations were then
performed for Cases B and D. To the extent that the simulations deviated from the
photographic evidence or eyewitness reports [e.g., complete collapse occurred], the
investigators adjusted the input, but only within the range of physical reality. Thus,
for instance,…the pulling forces on the perimeter columns by the sagging floors
were adjusted... (NIST, 2005, p. 142; emphasis added.)
The primary role of the floors in the collapse of the towers was to provide inward
pull forces that induced inward bowing of perimeter columns. (NIST, 2005, p. 180;
emphasis added.)

NIST contracted with Underwriters Laboratories, Inc. to conduct tests to obtain
information on the fire endurance of trusses like those in the WTC towers…. All
four test specimens sustained the maximum design load for approximately 2 hours
without collapsing… The Investigation Team was cautious about using these results
directly in the formulation of collapse hypotheses. In addition to the scaling issues raised
by the test results, the fires in the towers on September 11, and the resulting exposure of
the floor systems, were substantially different from the conditions in the test furnaces.
Nonetheless, the [empirical test] results established that this type of assembly was
capable of sustaining a large gravity load, without collapsing, for a substantial
period of time relative to the duration of the fires in any given location on
September 11. (NIST, 2005, p. 141; emphasis added.)

So how does the NIST team justify the WTC collapses, when actual models fail to collapse and
there are zero examples of fire-caused high-rise collapses? Easy, NIST concocted computergenerated
hypotheticals for very “severe” cases, called cases B and D (NIST, 2005, pp. 124-
138). Of course, the details are rather hidden to us. And they omit consideration of the
complete, rapid and symmetrical nature of the collapses.
Indeed, NIST makes the startling admission in a footnote on page 80 of their

Final Report:
The focus of the Investigation was on the sequence of events from the instant of aircraft
impact to the initiation of collapse for each tower. For brevity in this report, this sequence
is referred to as the "probable collapse sequence," although it does not actually include
the structural behavior of the tower after the conditions for collapse initiation were
reached... (NIST, 2005, p. 80, fn. 12; emphasis added.)
Again, on page 142, NIST admits that their computer simulation only proceeds until the building
is “poised for collapse”, thus ignoring any data from that time on.
The results were a simulation of the structural deterioration of each tower from the time of
aircraft impact to the time at which the building became unstable, i.e., was poised for
collapse. ...(NIST, 2005, p. 142; emphasis added.)
What about the subsequent complete, rapid and symmetrical collapse of the buildings? What
about the observed squibs? What
about the molten metal observed in the basement areas in large pools in both Towers and WTC 7
as well? Never mind all that: NIST did not discuss at all any data after the buildings were
“poised for collapse.” Well, some of us want to look at ALL the data, without "black-box"
computer simulations that are “adjusted,” perhaps to make them fit the desired outcome. An
hypothesis which is non-refutable is non-scientific.

[edit on 3/3/2007 by sp00n1]

Fisrt ill im not saying it was anything other then the planes that brought these buildings down so on to the other building that collapased .
Fact 1 no plane hits the building Fact 2 no jet fule is in the building to burn .
So the fire that started in the building was because of fire jumping .
(fire jumping is when eather the heat is intense enough or embers from a fire jump a fire brake. ( in this case the street ) and start a scendary fire .
come on ppl every one keeps trying to debunk the towers why is it no one even attempts to address the other building???
Im realy not into conspierses and just enjoy reading this stuff but realy .
SO HERES my CHALLANGE to all debunkers please explane how (with out a plan hitting without jet fule burning in it the other building copplased as well .
Bet no one even trys .

john gross looks nervous, fidgety and off balance. he is evasive and defensive and guarded in his responses.
in short, he's acting GUILTY! guilty, guilty, guilty. i hope he hasn't slept in three yrs., although i understand these type of people are smug in their sense of superiority.

the nist report contradicts itself. you can not lie well with science. they TRIED to pull a 'blinded me with science' approach, but there are too many people educated who still care for that to work.

what DOES work, though, is the 'one foot in front of the other' pace of our modern system. information flows at light speed, now, but people's motivation and sense of direction is like molasses in outer space.

gotta go do something virtual... bye for now.

Originally posted by sp00n1
NO, the steel did not get hot enough to loose loadbearing capacity!

Do some research instead assuming you know everything or regurgitating the same debunker statements that are debunked again and again...

The WTC has a safety ratio somewhere in the ballpark of 200:1. Even if it lost half its strength, it still has a 100:1 safety ratio BEFORE the steel is actually loaded to its max capacity.

The WTC had sooooo many redundancies that even it half of the columns and beams were severed it wouldnt matter!

Wow how do you know soo much on the subject?

Did you put temp probes in the the WTC when it was burning?

the fire works well cause it was working like a chimney bringing in a draft
so in turn becomes hotter
and concrete becomes so dry it crumbles after its baked for some time.

so it is possible to make temeratures hotter than "1800oF" which i think is quoted some where for the temperature of parafin burns at *kerosene*

Dont get me wrong I dont belive that that is the case In part cause no one knows.
It however seems incredibly suspicious that as it happens the millitary was doing excercises on this particular day an there was only 4 millitary jets keeping america safe.
Hah if only other countrys knew that america could be easy to bomb lol.

What people don't care about so much such as myself *being British*
Big deal you got "possibly attacked" by possible "terrorists"
We've had the IRA that have been payed for by america for 30 years.
So luckily were used to the "war on terror" lmao hence the SAS.

Originally posted by BlueRaja
The steel doesn't have to melt to lose its structural load bearing integrity. The fire was hot enough to weaken the steel, even if it wasn't enough to cause it to become molten.

This is just another myth that replaced the old myth.

If you want to align yourself with the "official" reports like a good little submissive, then it was the trusses that expanded from being heated (not columns losing strength!) that caused buckling, etc., until everything just falling straight down. There wasn't enough heat to sufficiently heat that many columns to a high enough temperature.