QUOTE (Malmoesoldier+Jun 2 2007, 05:14 PM)
I was talking about this when i said "And dont hide from this, the third time im writing it now."
there where people in WTC 7 that heard big explosions below floor 8. And there where Fire fighters that felt explosions and got banged around time after time. And there was fire fighters that saw flashes, i guess they to had an hallucination like the ones that saw molten steel, So many hallucinations that day.
So?
The building was hit by pieces of WTC 1.
Sufficient to knock an elevator out of its shaft.
WTC was on fire all day long.
There would have been failures along the way.
There would have made big bangs and flashes.
So what is your BEST evidence of ANYTHING sinister?
Arthur
QUOTE
And you are saying that they could melt the steel, PRICELESS!!.
I did and do say that I believe the fires could've melted steel, for the reasons I cited. Fires are nonlinear (chaotic) processes, and you can't assume that a linear model will be able to predict a chaotic system's behavior.
Which does, indeed, put me at-odds with the NIST report.
So how does that imply that I'm brainwashed into believing "The Official Story"? I'm saying they made a mistake.
I also showed you how to prove that explosives caused the towers' collapse. Measure the angle between the upper and lower floors and plot those angles versus time. Calculate what the angle-rates are, they'll show you the integrity of the structure. If the angle-rate is zero, then the structure is stable. If the angle-rate plot has a sudden jump from zero to some higher value, that's when the explosives went off. Now just correlate that time with the photos, and you should be able to detect the blast associated with that detonation.
Of course, if the angle-rates are never zero after the impact, and the angle-rates keep increasing up to the point where the collapse becomes obvious, then that just shows that no explosion caused the collapse of the towers. So you may not want to do this simple measurement, it can prove that you're the one who's been brainwashed.
QUOTE (reasonwhy+Jun 2 2007, 10:11 PM)
Now explain how an area surrounded by walls made up of mostly vents can build up pressure (to infinity as the paper suggests).
I already did explain this. Air has inertia. Its density at one atmosphere is roughly one kg/m^3. To expell it, you must put it into motion. This requires a force, and thus a pressure gradient.
The air pressure tends towards infinity because so does the exit velocity. And the exit velocity tends towards infinity because the ratio dv/da, where v(t) is the volume of the enclosure and a(t) is the vent area, tends towards infinity as h(t) approaches zero. This is rather intuitive. The air molecule that is an average distance (a_d) from the perimeter has to travel a_d to get out. The last remaining infinitesimal layer of air that must be expelled is composed of molecules that still are located an average distance a_d from the perimeter. But they have to move there in an infinitesimally short time and thus with infinite speed. (A more realistic model allows for leaks or for the survival of a thin cushion, as the authors note.)
This is an inconsequential singularity that gets shaved off from the continuum model.
I already did explain this. Air has inertia. Its density at one atmosphere is roughly one kg/m^3. To expell it, you must put it into motion. This requires a force, and thus a pressure gradient.
The air pressure tends towards infinity because so does the exit velocity. And the exit velocity tends towards infinity because the ratio dv/da, where v(t) is the volume of the enclosure and a(t) is the vent area, tends towards infinity as h(t) approaches zero. This is rather intuitive. The air molecule that is an average distance (a_d) from the perimeter has to travel a_d to get out. The last remaining infinitesimal layer of air that must be expelled is composed of molecules that still are located an average distance a_d from the perimeter. But they have to move there in an infinitesimally short time and thus with infinite speed. (A more realistic model allows for leaks or for the survival of a thin cushion, as the authors note.)
This is an inconsequential singularity that gets shaved off from the continuum model.
QUOTE (David B. Benson+Jun 2 2007, 10:15 PM)
The fire progression scenarios are graphed in NCSTAR1-5F, I think.
I'd appreciate your checking the worst case scenarios. (It seems NIST limited these to 750 F for the core columns, which is, if I didn't make a mistake, (434+273) K.) Hmm. Maybe it is truss temperatures?
Of course! I certainly never questioned that! I am quite certain many steel elements got quite hot! I do not have an issue with the fire and structural response models.
Your paper claims that "By annealing studies of column pieces collected after the
collapse, NIST documents that steel temperatures reached at least 600C."
That is something else entirely. The CD theorists will jump at your throats over this and just ignore the rest of the paper. This is an innocent error that migrated here from Bazant and Verdure, I think.
I'd appreciate your checking the worst case scenarios. (It seems NIST limited these to 750 F for the core columns, which is, if I didn't make a mistake, (434+273) K.) Hmm. Maybe it is truss temperatures?
Of course! I certainly never questioned that! I am quite certain many steel elements got quite hot! I do not have an issue with the fire and structural response models.
Your paper claims that "By annealing studies of column pieces collected after the
collapse, NIST documents that steel temperatures reached at least 600C."
That is something else entirely. The CD theorists will jump at your throats over this and just ignore the rest of the paper. This is an innocent error that migrated here from Bazant and Verdure, I think.
The bottom of page 4 and to the top of page 5 is a run on sentence. It makes for a hard read. It also reads "...for the lower part of tower" should be "...for the lower part of the tower"
Which brings me to my question, what of the freestanding core section? I know it would wreck havoc with the differential equation, but is it safe to assume it was not a major part of the progressive collapse?
Which brings me to my question, what of the freestanding core section? I know it would wreck havoc with the differential equation, but is it safe to assume it was not a major part of the progressive collapse?
QUOTE (Pierre-Normand+Jun 2 2007, 11:00 PM)
Your paper claims that "By annealing studies of column pieces collected after the collapse, NIST documents that steel temperatures reached at least 600C."
This is an innocent error that migrated here from Bazant and Verdure, I think.
NIST does not document this? The only part I recall in the steel sample studies was that no yield points could be developed on several samples. And there was something about paint, as well.
But it is all fairly meaningless since there is no way to tell building fires from Ground Zero fires. Or so I thought...
This is an innocent error that migrated here from Bazant and Verdure, I think.
NIST does not document this? The only part I recall in the steel sample studies was that no yield points could be developed on several samples. And there was something about paint, as well.
But it is all fairly meaningless since there is no way to tell building fires from Ground Zero fires. Or so I thought...
QUOTE (3bodyproblem+Jun 2 2007, 11:15 PM)
The bottom of page 4 and to the top of page 5 is a run on sentence. It makes for a hard read. It also reads "...for the lower part of tower" should be "...for the lower part of the tower"
Which brings me to my question, what of the freestanding core section? I know it would wreck havoc with the differential equation, but is it safe to assume it was not a major part of the progressive collapse?
(1) Could you send me an e-mail of the first paragraph? Thanks.
(2) For WTC 1 it was so small that it can be ignored. The paper gives a crush-down time of 12.8 seconds and I am very content with this figure, since it gives good agreement with the Heath video.
For WTC 2 it looks more and more that additional work will have to be done. The paper says something about needing a three dimensional model, but I opine that the one dimensional one can be tweaked enough. For the free-standing core section, the main problem is to determine its mass versus height. Then this much mass can be assumed not the exist, for the reasons that shagster gave yesterday.
Which brings me to my question, what of the freestanding core section? I know it would wreck havoc with the differential equation, but is it safe to assume it was not a major part of the progressive collapse?
(1) Could you send me an e-mail of the first paragraph? Thanks.
(2) For WTC 1 it was so small that it can be ignored. The paper gives a crush-down time of 12.8 seconds and I am very content with this figure, since it gives good agreement with the Heath video.
For WTC 2 it looks more and more that additional work will have to be done. The paper says something about needing a three dimensional model, but I opine that the one dimensional one can be tweaked enough. For the free-standing core section, the main problem is to determine its mass versus height. Then this much mass can be assumed not the exist, for the reasons that shagster gave yesterday.
[removed]
QUOTE (David B. Benson+Jun 2 2007, 06:21 PM)
NIST does not document this? The only part I recall in the steel sample studies was that no yield points could be developed on several samples. And there was something about paint, as well.
But it is all fairly meaningless since there is no way to tell building fires from Ground Zero fires. Or so I thought...
David,
See NIST NCSTAR 1-3C Sec 7.4 Fire Exposure and Temps reached by Steel
The annealing studies that support this are in 1-3E.
Arthur
QUOTE (Malmoesoldier+Jun 2 2007, 06:34 PM)
And other skyscrapers has burned for 4-18 hours without the steel collapsing. Fire proofing only last for 2 hours i HOPE you KNOW that, SO WHY DID THE OTHER SKYSCRAPERS DONT COLLAPSE? please tell me, was the WTC steel much weaker then theirs? 
Did the other skyscrapers have 767s fly into them?
NO?
So guess you REALLY can't compare them now can you?
Arthur
Did the other skyscrapers have 767s fly into them?
NO?
So guess you REALLY can't compare them now can you?
Arthur
QUOTE (adoucette+Jun 2 2007, 11:40 PM)
Did the other skyscrapers have 767s fly into them?
NO?
So guess you REALLY can't compare them now can you?
Arthur
adoucette i really have you in a corner now. NIST says in their report that the plane crash dident do any seriously damage, that the building would STILL BE STANDING!!! if it wasnt for the fire proofing that got destroyed. I think you need to read the NIST report
The 110-story towers of the World Trade Center were designed to withstand as a whole the forces caused by a horizontal impact of a large commercial aircraft. So why did a total collapse occur? (Bazant and Zhou, 2002, p. 2.)
“because the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure” (Eagar and Musso, 2001).
So WHY did the wtc collapse adoucette??
NO?
So guess you REALLY can't compare them now can you?
Arthur
adoucette i really have you in a corner now. NIST says in their report that the plane crash dident do any seriously damage, that the building would STILL BE STANDING!!! if it wasnt for the fire proofing that got destroyed. I think you need to read the NIST report
The 110-story towers of the World Trade Center were designed to withstand as a whole the forces caused by a horizontal impact of a large commercial aircraft. So why did a total collapse occur? (Bazant and Zhou, 2002, p. 2.)
“because the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure” (Eagar and Musso, 2001).
So WHY did the wtc collapse adoucette??
QUOTE (Malmoesoldier+Jun 2 2007, 11:34 PM)
James Curran - "We started filing out and following the line of the building. i got just to underneath the north walkway. a guy started screaming to run. When i got underneath the north bridge i looked back and you heard it, i heard like every floor went chu-chu-chu. Looked back and from the pressure everything was getting blown out of the floors before it actually collapsed."
BEFORE IT COLLAPSED?. demolition my friend.
I don't think you understand this quote. Why do you think they were running?
QUOTE (3bodyproblem+Jun 2 2007, 11:53 PM)
I don't think you understand this quote. Why do you think they were running?
Because he was told to run and they heard big explosions and knew it was coming down.
"everything was getting blown out of the floors before it actually collapsed."
BEFORE it collapsed. Did you read that part?.
Hes talking about the "puffs" i guess, and thats something you can explain right?. NIST havnt done it.
Because he was told to run and they heard big explosions and knew it was coming down.
"everything was getting blown out of the floors before it actually collapsed."
BEFORE it collapsed. Did you read that part?.
Hes talking about the "puffs" i guess, and thats something you can explain right?. NIST havnt done it.
QUOTE (Pierre-Normand+Jun 2 2007, 02:50 PM)
I already did explain this. Air has inertia. Its density at one atmosphere is roughly one kg/m^3. To expell it, you must put it into motion. This requires a force, and thus a pressure gradient.
The air pressure tends towards infinity because so does the exit velocity. And the exit velocity tends towards infinity because the ratio dv/da, where v(t) is the volume of the enclosure and a(t) is the vent area, tends towards infinity as h(t) approaches zero. This is rather intuitive. The air molecule that is an average distance (a_d) from the perimeter has to travel a_d to get out. The last remaining infinitesimal layer of air that must be expelled is composed of molecules that still are located an average distance a_d from the perimeter. But they have to move there in an infinitesimally short time and thus with infinite speed. (A more realistic model allows for leaks or for the survival of a thin cushion, as the authors note.)
This is an inconsequential singularity that gets shaved off from the continuum model.
I looked at the formula and problem closer.
They pretend the WTC did not have a core 1/3 the floor area in the center of the building that does not collapse (if you believe the pancake theory) so that the air would not need to be expelled from the center at great velocity. In fact the core to open floor interface would be another venting area almost as large as the vent to the outside. They then use the velocity from the bottom of the tower as an average to get the Mach speed for sonic booms.
The formula does not apply to the architecture of the WTC unless you think the entire floor fell as one unit (video evidence of the core standing proves this is not true).
The air pressure tends towards infinity because so does the exit velocity. And the exit velocity tends towards infinity because the ratio dv/da, where v(t) is the volume of the enclosure and a(t) is the vent area, tends towards infinity as h(t) approaches zero. This is rather intuitive. The air molecule that is an average distance (a_d) from the perimeter has to travel a_d to get out. The last remaining infinitesimal layer of air that must be expelled is composed of molecules that still are located an average distance a_d from the perimeter. But they have to move there in an infinitesimally short time and thus with infinite speed. (A more realistic model allows for leaks or for the survival of a thin cushion, as the authors note.)
This is an inconsequential singularity that gets shaved off from the continuum model.
I looked at the formula and problem closer.
They pretend the WTC did not have a core 1/3 the floor area in the center of the building that does not collapse (if you believe the pancake theory) so that the air would not need to be expelled from the center at great velocity. In fact the core to open floor interface would be another venting area almost as large as the vent to the outside. They then use the velocity from the bottom of the tower as an average to get the Mach speed for sonic booms.
The formula does not apply to the architecture of the WTC unless you think the entire floor fell as one unit (video evidence of the core standing proves this is not true).
QUOTE (Malmoesoldier+Jun 2 2007, 06:49 PM)
adoucette i really have you in a corner now. NIST says in their report that the plane crash dident do any seriously damage, that the building would STILL BE STANDING!!! if it wasnt for the fire proofing that got destroyed. I think you need to read the NIST report
The 110-story towers of the World Trade Center were designed to withstand as a whole the forces caused by a horizontal impact of a large commercial aircraft. So why did a total collapse occur? (Bazant and Zhou, 2002, p. 2.)
“because the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure” (Eagar and Musso, 2001).
So WHY did the wtc collapse adoucette??
In a corner?
You have YET to bring up a new argument.
You're a JOKE, just posting what you find on other sites, thinking you've found something.
But so far not a single new idea.
For this last post.
YOU said other skyscrapers burned for a long time but didn't collapse so why did the WTC collapse?
But those didn't have a plane crash into them.
But you say, the WTC should have handled a plane crashing into them.
And they did.
They took the hit and yet still stood, but they tilted to one side (worse on WTC 2 which was a more energetic impact and created more asymetric damage).
But as you say, the fire proofing was knocked off much of the steel structure.
And that was the ultimate problem.
The gaps in the fireproofing allowed the steel to get to fairly high temps in even short periods of time, so even though the fires did move and burn out in fairly short times in most areas, the OPEN FLOOR PLANS of the WTC towers allowed the heat from the fires to REMAIN at high levels well past the time the fires had moved on.
These nearly floor wide high temps caused core steel temps to rise which caused the core columns to creep under the higher loads they were handling from both the tilt and the redistributed loads from the severed columns.
This creep (shortening) of the core columns increased the loads on the perimeter columns that the buildings were leaning towards from the impact damage
The multifloor fires also caused the long 60 ft trusses to sag and apply pull in forces to these heated perimeter columns causing them to bow in over multiple floors (see pictures in NIST of them bowing in over 4 ft over 3+ floors, something that CT'ers always ignore)
As the perimeter columns bowed in they redristibuted loads via the hat truss back to the heated core columns which caused them to shorten even more.
This load transfer see-saw between the core and the perimeter continued until the perimeter columns buckled and global collapse ensued.
See NIST NCSTAR 1-6
Arthur
The 110-story towers of the World Trade Center were designed to withstand as a whole the forces caused by a horizontal impact of a large commercial aircraft. So why did a total collapse occur? (Bazant and Zhou, 2002, p. 2.)
“because the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure” (Eagar and Musso, 2001).
So WHY did the wtc collapse adoucette??
In a corner?
You have YET to bring up a new argument.
You're a JOKE, just posting what you find on other sites, thinking you've found something.
But so far not a single new idea.
For this last post.
YOU said other skyscrapers burned for a long time but didn't collapse so why did the WTC collapse?
But those didn't have a plane crash into them.
But you say, the WTC should have handled a plane crashing into them.
And they did.
They took the hit and yet still stood, but they tilted to one side (worse on WTC 2 which was a more energetic impact and created more asymetric damage).
But as you say, the fire proofing was knocked off much of the steel structure.
And that was the ultimate problem.
The gaps in the fireproofing allowed the steel to get to fairly high temps in even short periods of time, so even though the fires did move and burn out in fairly short times in most areas, the OPEN FLOOR PLANS of the WTC towers allowed the heat from the fires to REMAIN at high levels well past the time the fires had moved on.
These nearly floor wide high temps caused core steel temps to rise which caused the core columns to creep under the higher loads they were handling from both the tilt and the redistributed loads from the severed columns.
This creep (shortening) of the core columns increased the loads on the perimeter columns that the buildings were leaning towards from the impact damage
The multifloor fires also caused the long 60 ft trusses to sag and apply pull in forces to these heated perimeter columns causing them to bow in over multiple floors (see pictures in NIST of them bowing in over 4 ft over 3+ floors, something that CT'ers always ignore)
As the perimeter columns bowed in they redristibuted loads via the hat truss back to the heated core columns which caused them to shorten even more.
This load transfer see-saw between the core and the perimeter continued until the perimeter columns buckled and global collapse ensued.
See NIST NCSTAR 1-6
Arthur
reasonwhy
Clap your hands together hard. The clap is so loud because the last bit of air between your palms reaches high velocity(I'm not sure that it is supersonic), crack a whip, the crack is of the tip going supersonic. Now imagine two bagel shaped flat surfaces that measure almost an acre and hitting each other at 451 mph. The last bit of air from between them would easily go supersonic even if all the windows AND the core are wide open. The momentary pulse of pressure could easily reach extremely high pressures.
Grumpy
Clap your hands together hard. The clap is so loud because the last bit of air between your palms reaches high velocity(I'm not sure that it is supersonic), crack a whip, the crack is of the tip going supersonic. Now imagine two bagel shaped flat surfaces that measure almost an acre and hitting each other at 451 mph. The last bit of air from between them would easily go supersonic even if all the windows AND the core are wide open. The momentary pulse of pressure could easily reach extremely high pressures.
Grumpy
QUOTE (reasonwhy+Jun 3 2007, 12:06 AM)
They pretend the WTC did not have a core 1/3 the floor area in the center of the building that does not collapse (if you believe the pancake theory) ...
In fact the core to open floor interface would be another venting area almost as large as the vent to the outside.
They then use the velocity from the bottom of the tower as an average to get the Mach speed for sonic booms.
The core certainly (mostly) collapsed. Inspection of steel samples shows that the pieces connecting the trusses to the core failed vertically (mostly) below the top block. So the core failed just right after the trusses.
Yes, 7% of the total floor area was voids in the core. However, it appears that only about 7% or less of the air escaped that way, for otherwise the video would show many, many more the 'puffs of dirty air' well below the main collapse front. Given the uncertainty in the vent ratio and the fact that the paper is right up to the page limit, this aspect had to go unstated.
Not as an average for the entire collapse. Just near the bottom.
In fact the core to open floor interface would be another venting area almost as large as the vent to the outside.
They then use the velocity from the bottom of the tower as an average to get the Mach speed for sonic booms.
The core certainly (mostly) collapsed. Inspection of steel samples shows that the pieces connecting the trusses to the core failed vertically (mostly) below the top block. So the core failed just right after the trusses.
Yes, 7% of the total floor area was voids in the core. However, it appears that only about 7% or less of the air escaped that way, for otherwise the video would show many, many more the 'puffs of dirty air' well below the main collapse front. Given the uncertainty in the vent ratio and the fact that the paper is right up to the page limit, this aspect had to go unstated.
Not as an average for the entire collapse. Just near the bottom.
QUOTE
And no there would not have been big bangs all day long. Especially not bangs that made the fire fighters fall to the ground and fly up in the AIR and did so they got banged around time after time, it was BIG explosions.
A CD with random explosions all day long...
QUOTE (->
| QUOTE |
| And no there would not have been big bangs all day long. Especially not bangs that made the fire fighters fall to the ground and fly up in the AIR and did so they got banged around time after time, it was BIG explosions. |
A CD with random explosions all day long...
800C cant weaken the steel!!!
You really are having problems with this concept aren't you? Steel doesn't melt like ice does, at one specific temperature, it gets more and more plastic (taffy-like) as it gets hotter.
http://www.engineeringtoolbox.com/young-modulus-d_773.html
http://www.nist.gov/public_affairs/Gayle-P...CST%20Final.pdf
QUOTE (Malmoesoldier+Jun 3 2007, 12:01 AM)
Because he was told to run and they heard big explosions and knew it was coming down.
"everything was getting blown out of the floors before it actually collapsed."
BEFORE it collapsed. Did you read that part?.
Hes talking about the "puffs" i guess, and thats something you can explain right?. NIST havnt done it.
They were running because the building "was" collapsing. That's why he used the qualifier
"actually" later in the statement.
Mr. Benson has done a fine job of explaining the "puffs" in his paper, I would encourage you to read it.
"everything was getting blown out of the floors before it actually collapsed."
BEFORE it collapsed. Did you read that part?.
Hes talking about the "puffs" i guess, and thats something you can explain right?. NIST havnt done it.
They were running because the building "was" collapsing. That's why he used the qualifier
"actually" later in the statement.
Mr. Benson has done a fine job of explaining the "puffs" in his paper, I would encourage you to read it.
QUOTE
But as you say, the fire proofing was knocked off much of the steel structure. And that was the ultimate problem.
NIST says that the building would still be STANDING if the fire proofing wasnt destroyed and if the fires weren so hott (NIST shows in a shotgun test that all the fire proofing like they say couldnt have been destroyed, and yet they say that it was) But if there was fire proofing or not doesnt matter, other skyscrapers has survived without collapsing MANY hours without fire proofing. And the temperatures was not hot at all in WTC. IF the temp reached 1000C it was ONLY for some minutes, NIST test shows this, that it went from the 33 min mark from 1100C to 400C at the 41 min mark. And 600-800 C in 45 min CANT weaken the steel and make the steel collapse.
UL's comments on testing WTC steel
September 2001
Loring Knoblauch, UL's CEO, told staff that UL had certified the steel used in the WTC
November 2003
I asked Knoblauch in writing about UL's involvement, and he responded in December confirming details.
"We tested the steel with all the required fireproofing on, and it did beautifully."
"As we did not do follow-up service on this kind of product, we can given an opinion only on the test sample which was indeed properly coated."
"We test the code requirements, and the steel clearly met [the NYC code] requirements and exceeded them."
That test Knoblauch was talking about was 1093C in 3 hours.
Me asking a question about the work station tests nist did to James A. Milke i talked to from: *www.fpe.umd.edu
Thanks for the awnser. One more question. The fire tests conducted by nist
was over 3 work stations right?. If at the 33 min mark the temperature was
1100C and at the 41 mark it was at around 400C. Lets say they did the test
over more work stations then 3, would the fires in those other work stations
affect the temperature of the others? would that change the result nist got
in their 3 work stations, that the temp went from 1100C at the 33 min mark
to 400C at the 41 min mark?.
His awnser.
I know they've done workstation tests, but am not familiar with the details of
them. In general, more work stations does not necessarily increase the average
temperature in the space. Keep in mind that the temperature in the upper
portion of the space is affected by more than the amount of fuel, depending on
the burning rate which is affected by the amount of ventilation available,
among other factors. You can explore this by applying a simple zone model or
even by some of the 'simple' algebraic equations found in the SFPE Handbook,
among other books.
Also keep in mind that there's an upper limit on the maximum temperature that
can be achieved. Temperatures in the upper part of the room can't be greater
than the temperature of the flames.
J Milke
So Grumpy can DROP!! his BS about that they only did it over 3 work stations, it doesnt matter if it was 3 or 10.
QUOTE (Malmoesoldier+Jun 2 2007, 07:36 PM)
IF the temp reached 1000C it was ONLY for some minutes, NIST test shows this, that it went from the 33 min mark from 1100C to 400C at the 41 min mark. And 600-800 C in 45 min CANT weaken the steel and make the steel collapse.
UL's comments on testing WTC steel
September 2001
Loring Knoblauch, UL's CEO, told staff that UL had certified the steel used in the WTC
November 2003
I asked Knoblauch in writing about UL's involvement, and he responded in December confirming details.
"We tested the steel with all the required fireproofing on, and it did beautifully."
"As we did not do follow-up service on this kind of product, we can given an opinion only on the test sample which was indeed properly coated."
"We test the code requirements, and the steel clearly met [the NYC code] requirements and exceeded them."
That test Knoblauch was talking about was 1093C in 3 hours.
Me asking a question about the work station tests nist did to James A. Milke i talked to from: *www.fpe.umd.edu
Thanks for the awnser. One more question. The fire tests conducted by nist
was over 3 work stations right?. If at the 33 min mark the temperature was
1100C and at the 41 mark it was at around 400C. Lets say they did the test
over more work stations then 3, would the fires in those other work stations
affect the temperature of the others? would that change the result nist got
in their 3 work stations, that the temp went from 1100C at the 33 min mark
to 400C at the 41 min mark?.
His awnser.
I know they've done workstation tests, but am not familiar with the details of
them. In general, more work stations does not necessarily increase the average
temperature in the space. Keep in mind that the temperature in the upper
portion of the space is affected by more than the amount of fuel, depending on
the burning rate which is affected by the amount of ventilation available,
among other factors. You can explore this by applying a simple zone model or
even by some of the 'simple' algebraic equations found in the SFPE Handbook,
among other books.
Also keep in mind that there's an upper limit on the maximum temperature that
can be achieved. Temperatures in the upper part of the room can't be greater
than the temperature of the flames.
J Milke
So Grumpy can DROP!! his BS about that they only did it over 3 work stations, it doesnt matter if it was 3 or 10.
As I said, incompetent people can't tell they are incompetent.
QUOTE (moe+)
And the temperatures was not hot at all in WTC.
What a loon.
While the ultimate TEMP would not vary that much based on number of workstations the amount of HEAT released would most definately vary based on number of work stations and it is primarily the amount of heat released over time that will determine how hot the columns get.
More workstations, hotter columns (particularly with damaged insulation)
Arthur
What a loon.
While the ultimate TEMP would not vary that much based on number of workstations the amount of HEAT released would most definately vary based on number of work stations and it is primarily the amount of heat released over time that will determine how hot the columns get.
More workstations, hotter columns (particularly with damaged insulation)
Arthur
Malmoesoldier
And it doesn't matter if the steel is at a high temp for 40 minutes or 40 seconds, when the steel got as hot as the fire(even if it was 600 C or 850C), it collapsed when it reached a temp that meant it was no longer strong enough to hold the load. That weakening occurs instantly as the steel heats.
Grumpy
And it doesn't matter if the steel is at a high temp for 40 minutes or 40 seconds, when the steel got as hot as the fire(even if it was 600 C or 850C), it collapsed when it reached a temp that meant it was no longer strong enough to hold the load. That weakening occurs instantly as the steel heats.
Grumpy
QUOTE
other skyscrapers has survived without collapsing MANY hours without fire proofing.
Name one.
QUOTE (Grumpy+Jun 3 2007, 12:44 AM)
Malmoesoldier
And it doesn't matter if the steel is at a high temp for 40 minutes or 40 seconds, when the steel got as hot as the fire(even if it was 600 C or 850C), it collapsed when it reached a temp that meant it was no longer strong enough to hold the load. That weakening occurs instantly as the steel heats.
Grumpy
LOL you guys are joking to much. SO WHY DIDNT ALL THE OTHER SKYSCRAPERS THAT BURNED LONGER THEN 40 SEC AND 40 MIN COLLAPSE THEN?
Damn, use your brain!!!.
NIST floor test was almost 4 hours long and that was with WTC STEEL and it was put under 700C. DID IT EVEN COME CLOSE TO COLLAPSE? NO...
And it doesn't matter if the steel is at a high temp for 40 minutes or 40 seconds, when the steel got as hot as the fire(even if it was 600 C or 850C), it collapsed when it reached a temp that meant it was no longer strong enough to hold the load. That weakening occurs instantly as the steel heats.
Grumpy
LOL you guys are joking to much. SO WHY DIDNT ALL THE OTHER SKYSCRAPERS THAT BURNED LONGER THEN 40 SEC AND 40 MIN COLLAPSE THEN?
Damn, use your brain!!!.
NIST floor test was almost 4 hours long and that was with WTC STEEL and it was put under 700C. DID IT EVEN COME CLOSE TO COLLAPSE? NO...
QUOTE (wcelliott+Jun 3 2007, 12:48 AM)
Name one.
The One Meridian Plaza fire
The First Interstate Bank fire
The 1 New York Plaza Fire
Caracas Tower Fire
WTC 1975 burned for 3 hours to
Malmoesoldier
Concrete reinforced cores and steel crossbraced frames. Entirely different structures than the towers. Not being hit by 125 ton aircraft traveling at~500 mph and full of fuel. Each case is different due to differences in construction and materials
But just like the overpass in California, fire CAN cause steel structures to collapse, all by itself.
Grumpy
QUOTE
SO WHY DIDNT ALL THE OTHER SKYSCRAPERS THAT BURNED LONGER THEN 40 SEC AND 40 MIN COLLAPSE THEN?
Concrete reinforced cores and steel crossbraced frames. Entirely different structures than the towers. Not being hit by 125 ton aircraft traveling at~500 mph and full of fuel. Each case is different due to differences in construction and materials
But just like the overpass in California, fire CAN cause steel structures to collapse, all by itself.
Grumpy
QUOTE
The One Meridian Plaza fire
The First Interstate Bank fire
The 1 New York Plaza Fire
Caracas Tower Fire
The First Interstate Bank fire
The 1 New York Plaza Fire
Caracas Tower Fire
None of those had fire-proofing?
Did they all have exposed steel structures?
Grumpy
it was ~400 mph. And the plane still did NO DAMAGE!!!!. NIST says that it only destroyed the fireproofing (They show in a shotgun test that the fireproofing couldnt have been destroyed like the say, and yet they say it) But it doesnt matter it there was fire proofing or not!!!!. The fires wasnt HOT enough!!!!. And stop with the BS about the plane crash IT DIDENT DO ANY DAMAGE!!!!!!
You are stupid as ***. THE STEEL IN THE OTHER SKYSCRAPERS DIDNT COLLAPSE, THE STEEL!!!!! You said 600-800 in 40 sec will make the steel collapse LOL. And NO they where not better built then WTC. You are 1. An disinformation guy like mark roberts, or 2. A real stupid person?
it was ~400 mph. And the plane still did NO DAMAGE!!!!. NIST says that it only destroyed the fireproofing (They show in a shotgun test that the fireproofing couldnt have been destroyed like the say, and yet they say it) But it doesnt matter it there was fire proofing or not!!!!. The fires wasnt HOT enough!!!!. And stop with the BS about the plane crash IT DIDENT DO ANY DAMAGE!!!!!!
You are stupid as ***. THE STEEL IN THE OTHER SKYSCRAPERS DIDNT COLLAPSE, THE STEEL!!!!! You said 600-800 in 40 sec will make the steel collapse LOL. And NO they where not better built then WTC. You are 1. An disinformation guy like mark roberts, or 2. A real stupid person?
QUOTE
And the plane still did NO DAMAGE!!!!.
How stupid are you? Did "NO DAMAGE"?!?
Aside from tearing huge gaping holes in the sides, destroying entire floors, and setting the buildings on-fire.
I'd say that was considerable damage.
The NIST thing you seem to keep quoting and misunderstanding says that the damage, while extensive, did not cause the buildings to collapse on their own. It was the combination of the fire effects and the structural damage that caused the collapse.
I only wish you had the decency to get embarrassed when you make stupid remarks like this, but clearly you don't. You're living in denial. You're persuading no one and you're not learning anything.
Go away.
QUOTE (wcelliott+Jun 3 2007, 01:10 AM)
None of those had fire-proofing?
Did they all have exposed steel structures?
Yes None of those had fire-proofing.
And yes they all had exposed steel structures.
About the The One Meridian Plaza Fire that raged 18 hours, gutting eight floors FEMA said this "although beams and girders sagged and twisted. under servere fire exposures. the columns continued to support their loads without obvious damage"
And what do you think i mean with "NO DAMAGE"?!? READ what i said more???. The plane crash wasnt the reason for the collapse. NIST says the plane crash HAS NOTING TO DO WITH IT, it was the fires that was hot they say and the fireproofing that was destroyed they said, it was the plane crash that destroyed the fire proofing they say but the OTHER damge the plane did was SMALL and not the reason for the collapse, it wes the FIRES they say. 1. the fire proofing wasnt destroyed like they say. 2. it doesnt matter if it was or not. 3. the fires wasnt hot thats an LIE.
QUOTE (David B. Benson+Jun 2 2007, 04:20 PM)
The core certainly (mostly) collapsed. Inspection of steel samples shows that the pieces connecting the trusses to the core failed vertically (mostly) below the top block. So the core failed just right after the trusses.
Yes, 7% of the total floor area was voids in the core. However, it appears that only about 7% or less of the air escaped that way, for otherwise the video would show many, many more the 'puffs of dirty air' well below the main collapse front. Given the uncertainty in the vent ratio and the fact that the paper is right up to the page limit, this aspect had to go unstated.
Not as an average for the entire collapse. Just near the bottom.
Your formula is based on the distance the air has to travel to vent. You use the entire 63 meters of the building. In reality it would be the distance of one of the long floor spans, approximately 22 meters. Put that into your calculation and instead of 461 mph you would have 160 MPH. With a .5 venting ratio you would only have 300 MPH at the bottom of the tower instead of 761 with a .66 ratio.
Are you honestly trying to claim the core collapsed at the same time as the open floors (did you state this in your paper, I have only had time to read part of it)?
BTW, Glad to here you and NF are not paid shills .
Yes, 7% of the total floor area was voids in the core. However, it appears that only about 7% or less of the air escaped that way, for otherwise the video would show many, many more the 'puffs of dirty air' well below the main collapse front. Given the uncertainty in the vent ratio and the fact that the paper is right up to the page limit, this aspect had to go unstated.
Not as an average for the entire collapse. Just near the bottom.
Your formula is based on the distance the air has to travel to vent. You use the entire 63 meters of the building. In reality it would be the distance of one of the long floor spans, approximately 22 meters. Put that into your calculation and instead of 461 mph you would have 160 MPH. With a .5 venting ratio you would only have 300 MPH at the bottom of the tower instead of 761 with a .66 ratio.
Are you honestly trying to claim the core collapsed at the same time as the open floors (did you state this in your paper, I have only had time to read part of it)?
BTW, Glad to here you and NF are not paid shills .
QUOTE (Malmoesoldier+Jun 3 2007, 01:26 AM)
None of those had fire-proofing.
Nonsense. Building codes required at least two hours worth of insulation on steel.
Further more, most older building construction uses a combination of concrete and steel, both structure load-bearing.
Nonsense. Building codes required at least two hours worth of insulation on steel.
Further more, most older building construction uses a combination of concrete and steel, both structure load-bearing.
QUOTE (David B. Benson+Jun 3 2007, 01:31 AM)
Nonsense. Building codes required at least two hours worth of insulation on steel.
Further more, most older building construction uses a combination of concrete and steel, both structure load-bearing.
What i mean is that they burned for 4-18 hours, the fire proofing is GONE after 2 hours. So they burned MANY MANY hours without fire proofing. And WTC was MUCH better built thats why they took them down with explosives
Further more, most older building construction uses a combination of concrete and steel, both structure load-bearing.
What i mean is that they burned for 4-18 hours, the fire proofing is GONE after 2 hours. So they burned MANY MANY hours without fire proofing. And WTC was MUCH better built thats why they took them down with explosives
Malmoesoldier
It was closer(in both cases) to 500 than to 400 The next sentence gets my vote for the stupidest, most ignorant, brainless things ever said on this forum.
It was closer(in both cases) to 500 than to 400 The next sentence gets my vote for the stupidest, most ignorant, brainless things ever said on this forum.
And stop with the BS about the plane crash IT DIDENT DO ANY DAMAGE!!!!!!
Or maybe this one.
The columns in that case were made of steel reinforced concrete, the towers were not, the Plaza was not hit by an Aircraft, both towers were, and the steel all sagged and twisted, just like in the towers, and the towers had no steel reinforced concrete columns to hold up that twisted and sagging steel so it fell down.
Grumpy
Mine too.
I think Malmo should leave.
He isn't learning anything, and he isn't contributing anything of merit to the discussion.
Malmo, go away.
Please stop the BS "continued to support their loads without obvious damage"
The fires didnt do ANY DAMAGE TO THE STEEL!!! "without obvious damage"
And The The First Interstate Bank bulding
The building has a structural steel frame, protected by a sprayed-on protective coating, with steel floor pans and lightweight concrete The exterior curtain walls are glass and aluminum.
THE *** STEEL DIDNT COLLAPSE!!.
And 700C in almost 4 HOURS STILL didnt make the NIST tests of WTC STEEL COLLAPSE. VERY STRANGE SINCE IT ONLY NEEDS 40 SEC FOR IT TO COLLAPSE DONT YOU THINK?
David -
I mentioned earlier that the best way to measure the descent-rate leading up to the collapse would be to measure the tilt-angle-rate as a function of time.
It's my contention that the definition of when the collapse(s) began was/is a question of definition, as even if the rate of descent were measured at 1mm/minute, it still indicates that the structure is in a state failure. It would be my guess that the WTC towers had non-zero angle rates from the moment of impact until the final collapse. If I'm correct in this and the angle-rates are continuous, then that in itself would completely rule out any CD.
While photographic/video footage is of insufficient resolution to measure descent-rates directly, it should be possible to measure the angle-from-vertical of the tops of both towers to sufficient accuracy to determine angle-rates, unless I'm mistaken.
I don't have access to good quality photos or video footage, but it occurred to me that this might make a nice appendix to your paper, and it shouldn't take too much additional hard work, especially compared to what you've already put into this very-well-written/well-thought-out paper.
Your views?
QUOTE
Grumpy
it was ~400 mph. And the plane still did NO DAMAGE!!!!.
it was ~400 mph. And the plane still did NO DAMAGE!!!!.
It was closer(in both cases) to 500 than to 400 The next sentence gets my vote for the stupidest, most ignorant, brainless things ever said on this forum.
QUOTE (->
| QUOTE |
| Grumpy it was ~400 mph. And the plane still did NO DAMAGE!!!!. |
It was closer(in both cases) to 500 than to 400 The next sentence gets my vote for the stupidest, most ignorant, brainless things ever said on this forum.
And stop with the BS about the plane crash IT DIDENT DO ANY DAMAGE!!!!!!
Or maybe this one.
QUOTE
About the The One Meridian Plaza Fire that raged 18 hours, gutting eight floors FEMA said this "although beams and girders sagged and twisted. under servere fire exposures. the columns continued to support their loads without obvious damage"
The columns in that case were made of steel reinforced concrete, the towers were not, the Plaza was not hit by an Aircraft, both towers were, and the steel all sagged and twisted, just like in the towers, and the towers had no steel reinforced concrete columns to hold up that twisted and sagging steel so it fell down.
Grumpy
QUOTE (reasonwhy+Jun 3 2007, 01:31 AM)
Your formula is based on the distance the air has to travel to vent. ...
Are you honestly trying to claim the core collapsed at the same time as the open floors (did you state this in your paper)?
(1) We'll see what the reviewers say. As I stated earlier, the evidence points to no more than 7% of the air escaping through the voids in the core.
(2) Yes, most of it. The paper does not explicitly state this, only that it is implicit in the B & V crush-down equation. Actually, it doesn't matter if the core is crushed a bit later than the floors, but given the way the channels and the interior truss seats failed, it seems clear to me that the core failed just after the trusses were ripped off. Remember, everything happens faster and faster. For WTC 1, by 1.8 seconds everything is dropping at about 11.7 m/s. That'll wreck the core pretty good.
Are you honestly trying to claim the core collapsed at the same time as the open floors (did you state this in your paper)?
(1) We'll see what the reviewers say. As I stated earlier, the evidence points to no more than 7% of the air escaping through the voids in the core.
(2) Yes, most of it. The paper does not explicitly state this, only that it is implicit in the B & V crush-down equation. Actually, it doesn't matter if the core is crushed a bit later than the floors, but given the way the channels and the interior truss seats failed, it seems clear to me that the core failed just after the trusses were ripped off. Remember, everything happens faster and faster. For WTC 1, by 1.8 seconds everything is dropping at about 11.7 m/s. That'll wreck the core pretty good.
QUOTE
The next sentence gets my vote for the stupidest, most ignorant, brainless things ever said on this forum.
Mine too.
I think Malmo should leave.
He isn't learning anything, and he isn't contributing anything of merit to the discussion.
Malmo, go away.
QUOTE
The columns in that case were made of steel reinforced concrete, the towers were not, the Plaza was not hit by an Aircraft, both towers were, and the steel all sagged and twisted, just like in the towers, and the towers had no steel reinforced concrete columns to hold up that twisted and sagging steel so it fell down.
Please stop the BS "continued to support their loads without obvious damage"
The fires didnt do ANY DAMAGE TO THE STEEL!!! "without obvious damage"
And The The First Interstate Bank bulding
The building has a structural steel frame, protected by a sprayed-on protective coating, with steel floor pans and lightweight concrete The exterior curtain walls are glass and aluminum.
THE *** STEEL DIDNT COLLAPSE!!.
And 700C in almost 4 HOURS STILL didnt make the NIST tests of WTC STEEL COLLAPSE. VERY STRANGE SINCE IT ONLY NEEDS 40 SEC FOR IT TO COLLAPSE DONT YOU THINK?
The Windsor Building fire demonstrates that a huge building-consuming fire, after burning for many hours can produce the collapse of parts of the building with weak steel supports lacking fire protection. It also shows that the collapse events that do occur are gradual and partial.
Time Collapse Situation
1:29 East face of the 21st floor collapsed
1:37 South middle section of several floors above the 21st floor gradually collapsed
1:50 Parts of floor slab with curtain walls collapsed
2:02 Parts of floor slab with curtain walls collapsed
2:11 Parts of floor slab with curtain walls collapsed
2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor
2:17 Parts of floor slab with curtain walls collapsed
2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed
2:51 Southeast corner of about 18th ~ 20th floors collapsed
3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor
3:48 Fire flame spurted out below the Upper Technical Floor
4:17 Debris on the Upper Technical Floor fell down
http*://911research.wtc7.net/wtc/analysis/compare/windsor.html
Time Collapse Situation
1:29 East face of the 21st floor collapsed
1:37 South middle section of several floors above the 21st floor gradually collapsed
1:50 Parts of floor slab with curtain walls collapsed
2:02 Parts of floor slab with curtain walls collapsed
2:11 Parts of floor slab with curtain walls collapsed
2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor
2:17 Parts of floor slab with curtain walls collapsed
2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed
2:51 Southeast corner of about 18th ~ 20th floors collapsed
3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor
3:48 Fire flame spurted out below the Upper Technical Floor
4:17 Debris on the Upper Technical Floor fell down
http*://911research.wtc7.net/wtc/analysis/compare/windsor.html
QUOTE
That'll wreck the core pretty good.
David -
I mentioned earlier that the best way to measure the descent-rate leading up to the collapse would be to measure the tilt-angle-rate as a function of time.
It's my contention that the definition of when the collapse(s) began was/is a question of definition, as even if the rate of descent were measured at 1mm/minute, it still indicates that the structure is in a state failure. It would be my guess that the WTC towers had non-zero angle rates from the moment of impact until the final collapse. If I'm correct in this and the angle-rates are continuous, then that in itself would completely rule out any CD.
While photographic/video footage is of insufficient resolution to measure descent-rates directly, it should be possible to measure the angle-from-vertical of the tops of both towers to sufficient accuracy to determine angle-rates, unless I'm mistaken.
I don't have access to good quality photos or video footage, but it occurred to me that this might make a nice appendix to your paper, and it shouldn't take too much additional hard work, especially compared to what you've already put into this very-well-written/well-thought-out paper.
Your views?
Steel is a good conductor and concrete is a poor conductor of heat. Thus in a fire, a steel frame will conduct heat away from the hotspots into the larger structure. As long as the fire does not consume the larger structure, this heat conductivity will keep the temperatures of the frame well below the fire temperatures. The same is not true of steel-reinforced-concrete structures, since concrete is not a good thermal conductor, and the thermal conductivity of the rebar inside the concrete is limited by its small mass and the embedding matrix of concrete.
Fires can cause spalling of concrete, but not of steel. This is because concrete has a small percentage of latent moisture, which is converted to steam by heat. Thus, a large fire can gradually erode a concrete structure to the point of collapse, whereas a fire can only threaten a steel-framed structure if it elevates steel temperatures to such an extent that it causes failures.
Fires can cause spalling of concrete, but not of steel. This is because concrete has a small percentage of latent moisture, which is converted to steam by heat. Thus, a large fire can gradually erode a concrete structure to the point of collapse, whereas a fire can only threaten a steel-framed structure if it elevates steel temperatures to such an extent that it causes failures.
Malmoesoldier
Two contradictory statements in the same post
The fires didnt do ANY DAMAGE TO THE STEEL!!! "without obvious damage"
I would call twisted, sagging steel "Damaged", in the towers we call it "Collapsed"
Yes, the steel reinforced concrete COLUMNS, DA.
If you are going to continue to rant, post PRATTs and refuse to present evidence and not proclamations then you are a troll, a particularly...intellectually challenged troll at that.
We don't feed trolls, but you can eat my shorts.
Grumpy
Not really, it's about 1/5th as conductive as aluminum and 1/8th as conductive as copper.
Since you're venturing into material properties, have you taken a look at the strength of steel versus temperature, yet? (Or are you going to keep making the same ludicrous assertions about how 800C steel is just as strong as it is at room temperature?)
http://www.engineeringtoolbox.com/young-modulus-d_773.html
While you're learning something at that site, go ahead and look up the coefficient of thermal expansion of steel, and calculate how much the steel trusses expanded when they reached the elevated temperatures of the fire.
Here's a link:
http://www.engineeringtoolbox.com/thermal-...tals-d_859.html
Now, combine those two concepts and what do you get? You get a soft taffy-like material that's stretchy and expanding from the heat, so it sags, right?
Then the fire cools off and the steel gets stiff again, and it starts to shrink...
But it's attached to the curtain walls and the central core...
Hmmm. Would you suppose that this might cause some structural problems? Like maybe yanking brackets out of the walls or something?
I guess that wasn't thermate, but a melted-down reactor core.
I guess that wasn't thermate, but a melted-down reactor core.
look, it could have been the reverse vampires in cohoots with the martian mindsuckers.
what it is is not as important as what isn't.
these people are dying of cancer, and your, or dr. jones', or judy woods', or gordon ross' or greenings' or NIST's best theories would do more justice to the world at large if you, and they, dropped the egos, and tried to get the theory to fit the data, instead of the common tactic around here(911 truth/antitruth) of getting the data to fit the conclusion.
(EDIT: i felt bad, because ross and woods ARE trying to fit the theory to the data)
remember 'ground zero', a term used for two things before nine one one, being ....a new beginning, ....or, ....a nuclear bomb's point of detonation.
coincidence?
maybe.
blood cancers are not respiratory diseases.
why not take the better debunker tack of claiming it was the exit signs and flourescent lights, or some other 'scientifically' molly coddled crap?
maybe it was directed energy from outerspace, and the cancers are the result of nano particles of toxins.
handwaving will not uncover the bigger truth of 911.
I just saw the handwriting on the wall and decided to beat the troothers to the punch.
Blood cancers are commonly caused by exposure to nasty chemicals.
Like what you get from burning plastic, for instance.
Let's see, I wonder if there were any computer monitors in the WTC...
I wonder if there was any vinyl upholstery...
I wonder if the carpets were made of any synthetic materials...
This illustrates my misgivings about the whole "model the event to the n-th degree" approach to explaining what happened at the WTC. Every model must necessarily be a simplified approximation to the real circumstances of the event. And every simplification, however reasonable, is an open invitation to the troothers to cite that as evidence that the models were generated in bad-faith, attempts at covering up The Truth about what happened that day.
That's why their basic tactic is to cite a factoid, then wait for us to explain the most-obvious explanation, then pounce on the whatever simplifying assumption we made.
The real situation is that the WTC were HUGE buildings with LOTS of deviations from expected-values/expected states, and squirrelly things happen in real life that don't get considered in models of any sort. That's not to say that the modeling process is dishonest, that's just to say that reality is more complex than any model can approach.
At some point we need to accept that idealized models are not going to answer every question or explain every factoid, and use some common sense.
No evidence of explosives were found. The assumptions that led troothers to expect the collapses to look different from what they actually looked like are all based in their ignorance of basic physics and basic engineering, plus the obviously overwhelming desire to make this into something else to blame the US government for. Osama bin Laden acknowledged planning the attacks, the hijackers' "martyr tapes" were released along with footage of Osama embracing them. Common sense says that it's easier to get 16 terrorists to hijack four airplanes than it would be to get 16 terrorists to hijack four airplanes AND plant tons of explosives all over the WTC without getting caught. No explosives were found, none were required.
Impact-damaged buildings fall after a big fire.
NIST made this one error when calculating the fires' intensity, making simplifying linear assumptions about fire, which is fundamentally chaotic, and that underestimated the temperatures achieved in the fires. This is the same mistake that you see all the time in analyzing stocks - they'll show the actual trading prices, which is clearly a chaotic/fractal curve, and plot a straight line over the top of the fractal and use the straight-line for their analyses.
In this instance, where steel's plasticity is a strong function of it's temperature (Malmo - read carefully: it's INSTANTANEOUS temperature), then the peaks in temperature are more significant than the average values.
Overall, though, NIST's analysis is probably 99% right, even if it were only 50% accurate. They got the big points correct, IMO, other than the fires' peak temperatures (which probably was capable of melting steel in some places under non-nominal conditions) and that would easily explain factoids about steel droplets being found and could even explain that faked shot of "molten thermate" pouring out the WTC. (Which none of the troothers bothered explaining how the "thermate" made it all the way to the perimeter of the structure in ton-quantities, still glowing red-hot, without spreading out over the floor and cooling into a puddle, but troothers' long-suit is dark innuendo, not explanations, so I'm not holding my breath on that one, either.)
And Newton, I'm not going to take much more BS from somebody who figures Osama bin Laden's word is worth more than the scientists' at NIST.
Didn't you know? Nobody dies of natural causes, that's just how the CIA/MiB make people disappear.
Two contradictory statements in the same post
QUOTE
"although beams and girders sagged and twisted
QUOTE (->
| QUOTE |
| "although beams and girders sagged and twisted |
The fires didnt do ANY DAMAGE TO THE STEEL!!! "without obvious damage"
I would call twisted, sagging steel "Damaged", in the towers we call it "Collapsed"
QUOTE
"continued to support their loads without obvious damage"
Yes, the steel reinforced concrete COLUMNS, DA.
If you are going to continue to rant, post PRATTs and refuse to present evidence and not proclamations then you are a troll, a particularly...intellectually challenged troll at that.
We don't feed trolls, but you can eat my shorts.
Grumpy
QUOTE (reasonwhy+Jun 3 2007, 12:06 AM)
They then use the velocity from the bottom of the tower as an average to get the Mach speed for sonic booms.
I see that David B. Benson responded already. But let me clarify further.
Equation (8) is a function of dz/dt, which is the vertical speed of the collapse front. So this a a function of height. The averaging spoken of at the end of the section is an averaging around the perimeter, not along the vertical dimension. Sonic booms significantly further above the collapsed pile (if there are any) at the end of the crush-down phase are entirely due to localized fluctuations.
I see that David B. Benson responded already. But let me clarify further.
Equation (8) is a function of dz/dt, which is the vertical speed of the collapse front. So this a a function of height. The averaging spoken of at the end of the section is an averaging around the perimeter, not along the vertical dimension. Sonic booms significantly further above the collapsed pile (if there are any) at the end of the crush-down phase are entirely due to localized fluctuations.
Grumpy. Read my posts again. The STEEL (Not talking about concrete) didnt collapse in any of the buldings i said. The steel didnt collapse when it was under 700C in the NIST tests in almost 4 hours, you said it only takes 40 sec. Strange then that it didnt collapse in the nist test. And look at the Time Collapse Situation om the madrid fire
Steel is a good conductor and concrete is a poor conductor of heat. Thus in a fire, a steel frame will conduct heat away from the hotspots into the larger structure. As long as the fire does not consume the larger structure, this heat conductivity will keep the temperatures of the frame well below the fire temperatures. The same is not true of steel-reinforced-concrete structures, since concrete is not a good thermal conductor, and the thermal conductivity of the rebar inside the concrete is limited by its small mass and the embedding matrix of concrete.
Fires can cause spalling of concrete, but not of steel. This is because concrete has a small percentage of latent moisture, which is converted to steam by heat. Thus, a large fire can gradually erode a concrete structure to the point of collapse, whereas a fire can only threaten a steel-framed structure if it elevates steel temperatures to such an extent that it causes failures.
Steel is a good conductor and concrete is a poor conductor of heat. Thus in a fire, a steel frame will conduct heat away from the hotspots into the larger structure. As long as the fire does not consume the larger structure, this heat conductivity will keep the temperatures of the frame well below the fire temperatures. The same is not true of steel-reinforced-concrete structures, since concrete is not a good thermal conductor, and the thermal conductivity of the rebar inside the concrete is limited by its small mass and the embedding matrix of concrete.
Fires can cause spalling of concrete, but not of steel. This is because concrete has a small percentage of latent moisture, which is converted to steam by heat. Thus, a large fire can gradually erode a concrete structure to the point of collapse, whereas a fire can only threaten a steel-framed structure if it elevates steel temperatures to such an extent that it causes failures.
QUOTE (Pierre-Normand+Jun 2 2007, 06:22 PM)
I see that David B. Benson responded already. But let me clarify further.
Equation (8) is a function of dz/dt, which is the vertical speed of the collapse front. So this a a function of height. The averaging spoken of at the end of the section is an averaging around the perimeter, not along the vertical dimension. Sonic booms significantly further above the collapsed pile (if there are any) at the end of the crush-down phase are entirely due to localized fluctuations.
Do you agree with DBB that the core floors and office floors collapsed at the same time ( even with the video evidence of the core standing momentarily) ?
Appears DBB doesn't care if it's accurate as long as it gets past the reviewers!
Equation (8) is a function of dz/dt, which is the vertical speed of the collapse front. So this a a function of height. The averaging spoken of at the end of the section is an averaging around the perimeter, not along the vertical dimension. Sonic booms significantly further above the collapsed pile (if there are any) at the end of the crush-down phase are entirely due to localized fluctuations.
Do you agree with DBB that the core floors and office floors collapsed at the same time ( even with the video evidence of the core standing momentarily) ?
Appears DBB doesn't care if it's accurate as long as it gets past the reviewers!
QUOTE
Steel is a good conductor and concrete is a poor conductor of heat.
Not really, it's about 1/5th as conductive as aluminum and 1/8th as conductive as copper.
Since you're venturing into material properties, have you taken a look at the strength of steel versus temperature, yet? (Or are you going to keep making the same ludicrous assertions about how 800C steel is just as strong as it is at room temperature?)
http://www.engineeringtoolbox.com/young-modulus-d_773.html
While you're learning something at that site, go ahead and look up the coefficient of thermal expansion of steel, and calculate how much the steel trusses expanded when they reached the elevated temperatures of the fire.
Here's a link:
http://www.engineeringtoolbox.com/thermal-...tals-d_859.html
Now, combine those two concepts and what do you get? You get a soft taffy-like material that's stretchy and expanding from the heat, so it sags, right?
Then the fire cools off and the steel gets stiff again, and it starts to shrink...
But it's attached to the curtain walls and the central core...
Hmmm. Would you suppose that this might cause some structural problems? Like maybe yanking brackets out of the walls or something?
QUOTE (Malmoesoldier+Jun 2 2007, 08:36 PM)
What i mean is that they burned for 4-18 hours, the fire proofing is GONE after 2 hours. So they burned MANY MANY hours without fire proofing.
NOPE,
As you pointed out, the fire burns up the fuel in an area and moves on, so while the building might have burnt for 4-18 hours that DOES NOT mean that the fires heated any one part of the structure for that long.
Of course in those other cases you are also dealing with INTACT fireproofing and/or Concrete and Steel.
Of course in those other cases the structure was fully INTACT and the loads were NORMAL on all the columns.
Of course in those other cases the buildings fire suppression systems were in use and/or the fires were fought by fire fighters.
So once again you are wrong.
Arthur
NOPE,
As you pointed out, the fire burns up the fuel in an area and moves on, so while the building might have burnt for 4-18 hours that DOES NOT mean that the fires heated any one part of the structure for that long.
Of course in those other cases you are also dealing with INTACT fireproofing and/or Concrete and Steel.
Of course in those other cases the structure was fully INTACT and the loads were NORMAL on all the columns.
Of course in those other cases the buildings fire suppression systems were in use and/or the fires were fought by fire fighters.
So once again you are wrong.
Arthur
QUOTE (reasonwhy+Jun 2 2007, 09:34 PM)
Do you agree with DBB that the core floors and office floors collapsed at the same time ( even with the video evidence of the core standing momentarily) ?
While there are some fairly grainy/smoky videos that show some core columns standing, there is little to no evidence of core flooring in them.
So I'd say its questionable.
I think if the core flooring was still intact then parts of the core might have remained standing.
The fact that it didn't and the speed at which it eventually collapsed argues for the remains to mainly be the vertical columns and not the floors.
Arthur
While there are some fairly grainy/smoky videos that show some core columns standing, there is little to no evidence of core flooring in them.
So I'd say its questionable.
I think if the core flooring was still intact then parts of the core might have remained standing.
The fact that it didn't and the speed at which it eventually collapsed argues for the remains to mainly be the vertical columns and not the floors.
Arthur
adoucette
I too think the floor collapse and the crush down were probably two interacting but distinct phenomenon with the floor collapse preceding by several stories the top blocks.
And I still think a Bell curve concrete size distribution centered on the average density for the energy involved would more acurately predict dust generation(surely not over 50%, more like 10% I think).
Grumpy
I too think the floor collapse and the crush down were probably two interacting but distinct phenomenon with the floor collapse preceding by several stories the top blocks.
And I still think a Bell curve concrete size distribution centered on the average density for the energy involved would more acurately predict dust generation(surely not over 50%, more like 10% I think).
Grumpy
QUOTE (Grumpy+Jun 3 2007, 03:33 AM)
adoucette
I too think the floor collapse and the crush down were probably two interacting but distinct phenomenon with the floor collapse preceding by several stories the top blocks.
Grumpy
I would also agree with this. After looking at numerous videos it appears the floor collapse precedes the upper section by 3 stories, at least in the first few seconds. There is no reason to believe this did not continue for the entire crush down. The upper sections decent seems to have been only impeded by the core (It is my opinion that the exterior columns did little to impede the upper section during the collapse.
I too think the floor collapse and the crush down were probably two interacting but distinct phenomenon with the floor collapse preceding by several stories the top blocks.
Grumpy
I would also agree with this. After looking at numerous videos it appears the floor collapse precedes the upper section by 3 stories, at least in the first few seconds. There is no reason to believe this did not continue for the entire crush down. The upper sections decent seems to have been only impeded by the core (It is my opinion that the exterior columns did little to impede the upper section during the collapse.
QUOTE
blood cancer in 911 rescue workers
sounds like radiation effects.
sounds like radiation effects.
I guess that wasn't thermate, but a melted-down reactor core.
QUOTE (wcelliott+Jun 3 2007, 07:50 AM)
I guess that wasn't thermate, but a melted-down reactor core.
look, it could have been the reverse vampires in cohoots with the martian mindsuckers.
what it is is not as important as what isn't.
these people are dying of cancer, and your, or dr. jones', or judy woods', or gordon ross' or greenings' or NIST's best theories would do more justice to the world at large if you, and they, dropped the egos, and tried to get the theory to fit the data, instead of the common tactic around here(911 truth/antitruth) of getting the data to fit the conclusion.
(EDIT: i felt bad, because ross and woods ARE trying to fit the theory to the data)
remember 'ground zero', a term used for two things before nine one one, being ....a new beginning, ....or, ....a nuclear bomb's point of detonation.
coincidence?
maybe.
blood cancers are not respiratory diseases.
why not take the better debunker tack of claiming it was the exit signs and flourescent lights, or some other 'scientifically' molly coddled crap?
maybe it was directed energy from outerspace, and the cancers are the result of nano particles of toxins.
handwaving will not uncover the bigger truth of 911.
QUOTE (3bodyproblem+Jun 3 2007, 04:50 AM)
I would also agree with this. After looking at numerous videos it appears the floor collapse precedes the upper section by 3 stories, at least in the first few seconds. There is no reason to believe this did not continue for the entire crush down. The upper sections decent seems to have been only impeded by the core (It is my opinion that the exterior columns did little to impede the upper section during the collapse.
3bodyproblem,
I posted an objection to this hypothesis yesterday. What do you think?
http://forum.physorg.com/index.php?showtop...ndpost&p=219774
3bodyproblem,
I posted an objection to this hypothesis yesterday. What do you think?
http://forum.physorg.com/index.php?showtop...ndpost&p=219774
QUOTE (newton+Jun 3 2007, 07:03 AM)
blood cancer in 911 rescue workers
sounds like radiation effects.
35,000 cases of leukemia diagnosed annually in the US. I had no idea that nuclear detonations were so common in this country.
sounds like radiation effects.
35,000 cases of leukemia diagnosed annually in the US. I had no idea that nuclear detonations were so common in this country.
QUOTE
blood cancers are not respiratory diseases.
I just saw the handwriting on the wall and decided to beat the troothers to the punch.
Blood cancers are commonly caused by exposure to nasty chemicals.
Like what you get from burning plastic, for instance.
Let's see, I wonder if there were any computer monitors in the WTC...
I wonder if there was any vinyl upholstery...
I wonder if the carpets were made of any synthetic materials...
This illustrates my misgivings about the whole "model the event to the n-th degree" approach to explaining what happened at the WTC. Every model must necessarily be a simplified approximation to the real circumstances of the event. And every simplification, however reasonable, is an open invitation to the troothers to cite that as evidence that the models were generated in bad-faith, attempts at covering up The Truth about what happened that day.
That's why their basic tactic is to cite a factoid, then wait for us to explain the most-obvious explanation, then pounce on the whatever simplifying assumption we made.
The real situation is that the WTC were HUGE buildings with LOTS of deviations from expected-values/expected states, and squirrelly things happen in real life that don't get considered in models of any sort. That's not to say that the modeling process is dishonest, that's just to say that reality is more complex than any model can approach.
At some point we need to accept that idealized models are not going to answer every question or explain every factoid, and use some common sense.
No evidence of explosives were found. The assumptions that led troothers to expect the collapses to look different from what they actually looked like are all based in their ignorance of basic physics and basic engineering, plus the obviously overwhelming desire to make this into something else to blame the US government for. Osama bin Laden acknowledged planning the attacks, the hijackers' "martyr tapes" were released along with footage of Osama embracing them. Common sense says that it's easier to get 16 terrorists to hijack four airplanes than it would be to get 16 terrorists to hijack four airplanes AND plant tons of explosives all over the WTC without getting caught. No explosives were found, none were required.
Impact-damaged buildings fall after a big fire.
NIST made this one error when calculating the fires' intensity, making simplifying linear assumptions about fire, which is fundamentally chaotic, and that underestimated the temperatures achieved in the fires. This is the same mistake that you see all the time in analyzing stocks - they'll show the actual trading prices, which is clearly a chaotic/fractal curve, and plot a straight line over the top of the fractal and use the straight-line for their analyses.
In this instance, where steel's plasticity is a strong function of it's temperature (Malmo - read carefully: it's INSTANTANEOUS temperature), then the peaks in temperature are more significant than the average values.
Overall, though, NIST's analysis is probably 99% right, even if it were only 50% accurate. They got the big points correct, IMO, other than the fires' peak temperatures (which probably was capable of melting steel in some places under non-nominal conditions) and that would easily explain factoids about steel droplets being found and could even explain that faked shot of "molten thermate" pouring out the WTC. (Which none of the troothers bothered explaining how the "thermate" made it all the way to the perimeter of the structure in ton-quantities, still glowing red-hot, without spreading out over the floor and cooling into a puddle, but troothers' long-suit is dark innuendo, not explanations, so I'm not holding my breath on that one, either.)
And Newton, I'm not going to take much more BS from somebody who figures Osama bin Laden's word is worth more than the scientists' at NIST.
QUOTE
35,000 cases of leukemia diagnosed annually in the US. I had no idea that nuclear detonations were so common in this country.
Didn't you know? Nobody dies of natural causes, that's just how the CIA/MiB make people disappear.
adoucette
The first interstate bank building only had lightweight concrete, it was a structural steel frame building.
The first interstate bank building only had lightweight concrete, it was a structural steel frame building.
Of course in those other cases the buildings fire suppression systems were in use and/or the fires were fought by fire fighters.
No the fires burned MANY hours without being fought, check the facts before talking. So again the steel dit NOT collapse, and it burned for many more hours then WTC.
Grumpy
I still wonder why the floor tests of WTC steel NIST did didnt fail. You said it only takes 40 sec for 600C. Sorry it took almost 4 hours in 700C AND DIDNT COME CLOSE TO COLLAPSE
wcelliott i think you should go away. you are just talking BS all day long
QUOTE
Of course in those other cases you are also dealing with INTACT fireproofing and/or Concrete and Steel.
The first interstate bank building only had lightweight concrete, it was a structural steel frame building.
QUOTE (->
| QUOTE |
| Of course in those other cases you are also dealing with INTACT fireproofing and/or Concrete and Steel. |
The first interstate bank building only had lightweight concrete, it was a structural steel frame building.
Of course in those other cases the buildings fire suppression systems were in use and/or the fires were fought by fire fighters.
No the fires burned MANY hours without being fought, check the facts before talking. So again the steel dit NOT collapse, and it burned for many more hours then WTC.
Grumpy
I still wonder why the floor tests of WTC steel NIST did didnt fail. You said it only takes 40 sec for 600C. Sorry it took almost 4 hours in 700C AND DIDNT COME CLOSE TO COLLAPSE
wcelliott i think you should go away. you are just talking BS all day long
WCELLIOTT:
I have looked at the tipping of the upper section of the towers in some detail. (See papers by Greening on 911Myths.com) Here is part of what I wrote on the tipping of WTC 2:
"WTC 2 started its rapid, “near free fall”, collapse about 56 minutes after it was struck by an aircraft, and during this post-impact, pre-collapse period the intense fires within the building gradually weakened the structure and induced a slow but irrevocable buckling of columns near the impact zone. Thus we could say that WTC 2 actually started to tip over as soon as it was hit by an aircraft, but the tipping was not noticeable because the average angular velocity was only about 1° per hour or 0.0003° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1. However, even this rate of tipping was too small to be noticeable. Nonetheless, the necessary conditions for the total collapse of WTC 2 were now being established through the continuous build up of strain energy in the columns on the south and east sides of the Tower. 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 30 floors above the impact zone pivoted en masse about the northeast corner, causing this section of the Tower to fall obliquely on to the floor below.
Because this failure occurred when the floors in the southeast corner of the 80th floor of WTC 2 were already lowered by up to 1 meter from the initial 3.7 m floor spacing, the upper block would have pivoted a maximum distance of 2.7 m before impacting the floor below. Application of the formula d = w sin q, (where q is the tilt angle), shows that such a failure mechanism would increase the initial 0.9° tilt angle of the upper section of WTC 2 by a further 2.4° giving a tilt angle at the moment of impact of the upper block of floors with the floor below of 3.3°. Thus for tilt angles between 0.9° and 3.3° the tipping of the upper section was occurring under the action of gravity and the conditions for the application of our mathematical description of the rotational motion were fully satisfied.
Bazant and Zhou, (B & Z), in their paper: “Why did the World Trade Center Collapse?” show that the horizontal shear force at the base of the tilting upper section of WTC 2 is equal to 3/8Mg sin 2q and estimate that the plastic shear resistance of WTC 2 columns near the impact zone was about 1/10.3 of the maximum horizontal shear. From this estimate B & Z conclude that the horizontal shear force equaled the plastic limit of the affected columns when sin 2q = 1/10.3 or when q = 2.8°. Thus B & Z predict that the upper section of WTC 2 should become unstable at a tilt angle of about 3°, in good agreement with our mathematical model......"
I have looked at the tipping of the upper section of the towers in some detail. (See papers by Greening on 911Myths.com) Here is part of what I wrote on the tipping of WTC 2:
"WTC 2 started its rapid, “near free fall”, collapse about 56 minutes after it was struck by an aircraft, and during this post-impact, pre-collapse period the intense fires within the building gradually weakened the structure and induced a slow but irrevocable buckling of columns near the impact zone. Thus we could say that WTC 2 actually started to tip over as soon as it was hit by an aircraft, but the tipping was not noticeable because the average angular velocity was only about 1° per hour or 0.0003° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1. However, even this rate of tipping was too small to be noticeable. Nonetheless, the necessary conditions for the total collapse of WTC 2 were now being established through the continuous build up of strain energy in the columns on the south and east sides of the Tower. 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 30 floors above the impact zone pivoted en masse about the northeast corner, causing this section of the Tower to fall obliquely on to the floor below.
Because this failure occurred when the floors in the southeast corner of the 80th floor of WTC 2 were already lowered by up to 1 meter from the initial 3.7 m floor spacing, the upper block would have pivoted a maximum distance of 2.7 m before impacting the floor below. Application of the formula d = w sin q, (where q is the tilt angle), shows that such a failure mechanism would increase the initial 0.9° tilt angle of the upper section of WTC 2 by a further 2.4° giving a tilt angle at the moment of impact of the upper block of floors with the floor below of 3.3°. Thus for tilt angles between 0.9° and 3.3° the tipping of the upper section was occurring under the action of gravity and the conditions for the application of our mathematical description of the rotational motion were fully satisfied.
Bazant and Zhou, (B & Z), in their paper: “Why did the World Trade Center Collapse?” show that the horizontal shear force at the base of the tilting upper section of WTC 2 is equal to 3/8Mg sin 2q and estimate that the plastic shear resistance of WTC 2 columns near the impact zone was about 1/10.3 of the maximum horizontal shear. From this estimate B & Z conclude that the horizontal shear force equaled the plastic limit of the affected columns when sin 2q = 1/10.3 or when q = 2.8°. Thus B & Z predict that the upper section of WTC 2 should become unstable at a tilt angle of about 3°, in good agreement with our mathematical model......"
Who would design these buildings for aircraft impacts but no jet fuel fires? ... Well, the answer is not the World Trade Center's design engineer
"our analysis indicated the biggest problem would be the fact that all the fuel would dump into the building. [But] the building structure would still be there." John Skilling
The steel used in the perimeter columns was super-strong steel: much of it rated to 1,000,000 PSI.
Loring Knoblauch, UL's CEO, told staff that UL had certified the steel used in the WTC "We tested the steel with all the required fireproofing on, and it did beautifully". This test was 3 hours long at 1093C.
And then they did the floor tests of WTC STEEL to and it didnt fail, I WONDER WHY
"our analysis indicated the biggest problem would be the fact that all the fuel would dump into the building. [But] the building structure would still be there." John Skilling
The steel used in the perimeter columns was super-strong steel: much of it rated to 1,000,000 PSI.
Loring Knoblauch, UL's CEO, told staff that UL had certified the steel used in the WTC "We tested the steel with all the required fireproofing on, and it did beautifully". This test was 3 hours long at 1093C.
And then they did the floor tests of WTC STEEL to and it didnt fail, I WONDER WHY
1. How many columns were severed?
NIST admits that only a small percentage of columns were severed: 14% in WTC 1 and 15% WTC 2. This is nowhere near the the number of columns that the designers claimed could have been removed without causing a problem.
2. How much were loads redistributed?
NIST admits that the web of steel formed by interlocking perimeter columns and spandrel plates were efficient at redistributing loads around the impact punctures. It estimates that loads on some columns increased by up to 35% while loads on other columns decreased by 20%. The increased loads are nowhere near those the designers claimed the columns could handle: increases of 2000% above the design live loads.
3. Fireproofing widely dislodged?
The idea that fireproofing was removed from most of the structural steel surfaces of the impact zones is essential to NIST's theory. NIST sought to "prove" that the plane crashes could do this by shooting shotguns at surfaces coated with spray-on foam insulation. Contrary to the popular notion that the jolts of the plane crashes could knocked off large amounts of spray-on insulation from steel not directly in the line of fire, the tests showed that it took being sprayed with shotgun pellets to remove the insulation. In addition to the fact that there is no evidence that a crashing Boeing 757 could have been transformed into the equivalent of the thousands of shotgun blasts it would take to blast the 6,000 square meters of surface area of structural steel in the fire areas, Ryan makes another argument based on the available energy.
NIST says 2500 MJ of kinetic energy from plane that hit WTC1
Calculations show that all this energy was consumed in crushing aircraft and breaking columns and floors
Shotgun tests found that 1 MJ per sq meter was needed to dislodge fireproofing
For the areas in question, intact floors and columns had 6000 sq meters of surface area
Calculations by Tomasz Wierzbicki of MIT
NIST admits that only a small percentage of columns were severed: 14% in WTC 1 and 15% WTC 2. This is nowhere near the the number of columns that the designers claimed could have been removed without causing a problem.
2. How much were loads redistributed?
NIST admits that the web of steel formed by interlocking perimeter columns and spandrel plates were efficient at redistributing loads around the impact punctures. It estimates that loads on some columns increased by up to 35% while loads on other columns decreased by 20%. The increased loads are nowhere near those the designers claimed the columns could handle: increases of 2000% above the design live loads.
3. Fireproofing widely dislodged?
The idea that fireproofing was removed from most of the structural steel surfaces of the impact zones is essential to NIST's theory. NIST sought to "prove" that the plane crashes could do this by shooting shotguns at surfaces coated with spray-on foam insulation. Contrary to the popular notion that the jolts of the plane crashes could knocked off large amounts of spray-on insulation from steel not directly in the line of fire, the tests showed that it took being sprayed with shotgun pellets to remove the insulation. In addition to the fact that there is no evidence that a crashing Boeing 757 could have been transformed into the equivalent of the thousands of shotgun blasts it would take to blast the 6,000 square meters of surface area of structural steel in the fire areas, Ryan makes another argument based on the available energy.
NIST says 2500 MJ of kinetic energy from plane that hit WTC1
Calculations show that all this energy was consumed in crushing aircraft and breaking columns and floors
Shotgun tests found that 1 MJ per sq meter was needed to dislodge fireproofing
For the areas in question, intact floors and columns had 6000 sq meters of surface area
Calculations by Tomasz Wierzbicki of MIT
QUOTE (Pierre-Normand+Jun 3 2007, 09:16 AM)
3bodyproblem,
I posted an objection to this hypothesis yesterday. What do you think?
http://forum.physorg.com/index.php?showtop...ndpost&p=
Pierre: I see what you are saying and yes when dealing with such a large masses, momentum transfer is key factor. I think however that the "pancaking" (i hate using that term for fear of confusing people) was limited to 3 stories below the upper section at least at the point where the upper section begins to move noticeably. I postulated that there was no reason this did not continue for the entire crush down. Perhaps I was wrong.
What I have referred to is as a "critical mass" would be Zone B in Mr. Bensons et al. model. If Zone B was immediately behind the floor wave by 3 stories (I'm holding to 3 stories because of the exterior columns design) the upper section is now exerting a lateral force on the top of the column as the last exterior truss connection is severed. At this point the connection to the next lowest column is subjected to a torque and the bolts are sheared. When the bolts are sheared and the exterior column begins to fall away from the perimeter, Zone B discharges mass proportional to the thickness of the exterior column plate steel. During this discharge the pressure in Zone B is reduced, and perhaps it is reduced enough to allow it to catch up to the floor wave? I'm not sure if it is possible to work out an answer to this postulate or not. In effect the mass in Zone B would oscillating very fast every 3 floors in the decent. This becomes more reasonable later in the collapse when much of the mass has been converted to small particles and is easily discharged.
I posted an objection to this hypothesis yesterday. What do you think?
http://forum.physorg.com/index.php?showtop...ndpost&p=
Pierre: I see what you are saying and yes when dealing with such a large masses, momentum transfer is key factor. I think however that the "pancaking" (i hate using that term for fear of confusing people) was limited to 3 stories below the upper section at least at the point where the upper section begins to move noticeably. I postulated that there was no reason this did not continue for the entire crush down. Perhaps I was wrong.
What I have referred to is as a "critical mass" would be Zone B in Mr. Bensons et al. model. If Zone B was immediately behind the floor wave by 3 stories (I'm holding to 3 stories because of the exterior columns design) the upper section is now exerting a lateral force on the top of the column as the last exterior truss connection is severed. At this point the connection to the next lowest column is subjected to a torque and the bolts are sheared. When the bolts are sheared and the exterior column begins to fall away from the perimeter, Zone B discharges mass proportional to the thickness of the exterior column plate steel. During this discharge the pressure in Zone B is reduced, and perhaps it is reduced enough to allow it to catch up to the floor wave? I'm not sure if it is possible to work out an answer to this postulate or not. In effect the mass in Zone B would oscillating very fast every 3 floors in the decent. This becomes more reasonable later in the collapse when much of the mass has been converted to small particles and is easily discharged.
NEU-FONZE said:
So your story is that the most of the motion of the top 30 floors happened just before the collapse began and all that mass that was now free to move in repsonse to gravity somehow recovered its original position and came straight down into the footprint of the building?
Could we please have your technical credentials?
QUOTE
I have looked at the tipping of the upper section of the towers in some detail. (See papers by Greening on 911Myths.com) Here is part of what I wrote on the tipping of WTC 2:
"WTC 2 started its rapid, “near free fall”, collapse about 56 minutes after it was struck by an aircraft, and during this post-impact, pre-collapse period the intense fires within the building gradually weakened the structure and induced a slow but irrevocable buckling of columns near the impact zone. Thus we could say that WTC 2 actually started to tip over as soon as it was hit by an aircraft, but the tipping was not noticeable because the average angular velocity was only about 1° per hour or 0.0003° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1. However, even this rate of tipping was too small to be noticeable. Nonetheless, the necessary conditions for the total collapse of WTC 2 were now being established through the continuous build up of strain energy in the columns on the south and east sides of the Tower. 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 30 floors above the impact zone pivoted en masse about the northeast corner, causing this section of the Tower to fall obliquely on to the floor below.
"WTC 2 started its rapid, “near free fall”, collapse about 56 minutes after it was struck by an aircraft, and during this post-impact, pre-collapse period the intense fires within the building gradually weakened the structure and induced a slow but irrevocable buckling of columns near the impact zone. Thus we could say that WTC 2 actually started to tip over as soon as it was hit by an aircraft, but the tipping was not noticeable because the average angular velocity was only about 1° per hour or 0.0003° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1. However, even this rate of tipping was too small to be noticeable. Nonetheless, the necessary conditions for the total collapse of WTC 2 were now being established through the continuous build up of strain energy in the columns on the south and east sides of the Tower. 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 30 floors above the impact zone pivoted en masse about the northeast corner, causing this section of the Tower to fall obliquely on to the floor below.
So your story is that the most of the motion of the top 30 floors happened just before the collapse began and all that mass that was now free to move in repsonse to gravity somehow recovered its original position and came straight down into the footprint of the building?
Could we please have your technical credentials?
QUOTE (ChE_n_PhysicsGuy+Jun 3 2007, 02:18 PM)
NEU-FONZE said:
So your story is that the most of the motion of the top 30 floors happened just before the collapse began and all that mass that was now free to move in repsonse to gravity somehow recovered its original position and came straight down into the footprint of the building?
Could we please have your technical credentials?
Take a close look at the video and you can see when the upper section actually makes contact with the exterior wall and corrects itself, there is a noticeable ejection of debris when this happens. And the response to the upper section breaking free to move in response to gravity is to move until towards the center of the larger attracting mass Here on earth that would be straight down into the footprint, although you are kinda wrong there as well. It didn't really fall into its own footprint now did it?
I have tons of street cred
So your story is that the most of the motion of the top 30 floors happened just before the collapse began and all that mass that was now free to move in repsonse to gravity somehow recovered its original position and came straight down into the footprint of the building?
Could we please have your technical credentials?
Take a close look at the video and you can see when the upper section actually makes contact with the exterior wall and corrects itself, there is a noticeable ejection of debris when this happens. And the response to the upper section breaking free to move in response to gravity is to move until towards the center of the larger attracting mass Here on earth that would be straight down into the footprint, although you are kinda wrong there as well. It didn't really fall into its own footprint now did it?
I have tons of street cred
Will someone please calculate the energy contained in the "Blisk" or Blade disk from the front of one of the engines on a 757. This disk is made mostly of Titanium blades over four feet long, spining at top speedX2 engines. When they hit the outer frame of the tower they probably flew into little, high speed projectiles in all directions EXCEPT straight back, something like an eight foot Claymore mine.
Bye bye fireproofing!!!
It is small details of the collapse that are the most interesting("bageling", FAE,etc.), the main concensus seems to be...
Plane hit building, building fall down, go boom.
Grumpy
Bye bye fireproofing!!!
It is small details of the collapse that are the most interesting("bageling", FAE,etc.), the main concensus seems to be...
Plane hit building, building fall down, go boom.
Grumpy
QUOTE (Malmoesoldier+Jun 3 2007, 08:59 AM)
1. How many columns were severed?
NIST admits that only a small percentage of columns were severed: 14% in WTC 1 and 15% WTC 2. This is nowhere near the the number of columns that the designers claimed could have been removed without causing a problem.
% of columns isn't the issue, its mainly Core columns that were the issue and they aren't the same.
The REAL issue is that the loss of core columns caused the top to tilt.
The designers didn't make that claim, but even so, the quote was only about increases in LIVE loads and it pertained only to the perimeter columns and had to do with dealing with WIND loads, which of course were NOT the issue on 9/11.
The designers didn't make that claim, but even so, the quote was only about increases in LIVE loads and it pertained only to the perimeter columns and had to do with dealing with WIND loads, which of course were NOT the issue on 9/11.
3. Fireproofing widely dislodged?
Yes, and we dealt with this idocy from Ryan and Wierzbicki just recently in this thread. Do a search. Learn something.
Arthur
no, really.
no, really.
Radiation Exposure
Exposure to radioactivity has been suggested as a risk factor but accounts for a very small number of cases.
all of a sudden, ground zero workers are all getting the same 'relatively uncommon cancer', and it's onset is rapid.
the difference between radiation , and toxic dust/fumes, is radiation's effects are far faster.
the difference between radiation , and toxic dust/fumes, is radiation's effects are far faster.
Types of Cancer Associated With Ionizing Radiation
Leukemia was at one time thought to be the major cancer to arise from high-dose radiation exposure, based on the experience with people exposed to the atomic blasts in Japan. It is now known that other cancers can result from radiation exposure, although they may take longer to develop (usually at least 10 to 15 years). Leukemias, by contrast, begin appearing as early as 2 years after acute radiation exposure.
Studies of the survivors of the atomic blasts have demonstrated that high-dose radiation (at least 100cGy) increases the risk of developing several types of cancer.
* For these survivors, the risk of developing leukemia is five and a half times greater than in the general public. Children appear to be twice as sensitive as adults to the leukemia-causing effects of radiation, and unborn children exposed to radiation in the uterus are even more sensitive.
* The risk for developing any type of cancer in those highly exposed to an atomic blast is about 50% higher than the risk in those not exposed.
* Female breast cancer risk is more than twice as high as normal, and women who are exposed when under the age of 20 are found to be at higher risk than older women.
* The risk of developing lung cancer is 50% higher, and the risk for multiple myeloma is more than twice as high as in the general population.
Didn't you know? Nobody dies of natural causes, that's just how the CIA/MiB make people disappear.
actually, heart attacks are much easier, and immediate.
I'm loving the dark innuendo, but I just wish you'd actually *say* what you keep implying.
You think they, excuse me, They, **nuked** the WTC, don't you?
C'mon, say it. Spit it out.
It isn't like you could lose any more credibility than you already have (trusting Osama bin Laden's word while accusing NIST scientists of being dishonest).
Or, maybe the concrete dust got inhaled.
http://greenwood.cr.usgs.gov/energy/factsh.../FS-163-97.html
" Fly ash is commonly used as an additive to concrete building products, but the radioactivity of typical fly ash is not significantly different from that of more conventional concrete additives or other building materials such as granite or red brick. One extreme calculation that assumed high proportions of fly-ash-rich concrete in a residence suggested a dose enhancement, compared to normal concrete, of 3 percent of the natural environmental radiation.
Another consideration is that low-density, fly-ash-rich concrete products may be a source of radon gas. Direct measurement of this contribution to indoor radon is complicated by the much larger contribution from underlying soil and rock (see fig. 4). The emanation of radon gas from fly ash is less than from natural soil of similar uranium content. Present calculations indicate that concrete building products of all types contribute less than 10 percent of the total indoor radon. "
Then again, concrete as a slab in the basement is a slightly different situation than concrete dust in the lungs.
Thank you, NF, for this.
If this data were plotted versus time for each of the two towers, I think this plot alone would serve to sink any and all CD theories.
I, too, expected that the angle-rate started at-impact and proceeded to grow monotonically until the collapse event itself. If the plot were sufficiently fine-grained (instead of a point here at one value and a point there at another and a straight line interpolated in between) it could be seen that the lack of a discontinuity in the angle-rate plot means that no CD-explosion occurred. A CD explosion would necessarily result in an abrupt change in the angle-rate, so if the angle-rate curve is continuous, then there were no discrete events contributing to the buildings' collapse.
I appreciate the fact that this additional proof should be unnecessary, but we're clearly dealing with people who aren't open to the explanations provided to-date, and this argument can be made simple enough that perhaps even Malmo could follow the logic.
Where are the PROOF that the core was damage????
And no i dont need to do a search. NIST proves in the shotgun test that the fireproofing couldnt have been destroyed like they say. And fire proofing or not under 45 min doesnt matter!!! the fires wasnt hot enough to make the steel collapse so stop the BS. 700C in 4 hours CANT WEAKEN THE STEEL AND MAKE IT COLLAPSE. Do you understand?????
http://www.engineeringtoolbox.com/young-modulus-d_773.html
Read that and tell us all how strong steel is at 700C.
Here's a hint: the table doesn't even go up to 700C, because it's already beyond steel's critical temperature, where force applied just makes the steel undergo plastic deformation.
"Yield strength
Yield strength, or the yield point, is defined in engineering as the amount of strain that a material can undergo before moving from elastic deformation into plastic deformation."
http://www.engineeringtoolbox.com/young-modulus-d_417.html
This is the temperature that blacksmiths heat up their steel to when they want to bend/form it to shape.
Idiot.
I have an alternative explanation that works even better.
The MiB, using alien technology from the Roswell crash, discovered a way to make Godzilla invisible.
I have an alternative explanation that works even better.
The MiB, using alien technology from the Roswell crash, discovered a way to make Godzilla invisible.
i'll look in to this.
anything's possible.
I've seen actual photographs of the sprayed-on insulation on the steel trusses of at the WTC taken during routine building inspections, and the insulation coverage was spotty, at best. The spray-on fireproofing had a natural tendency to *fall off* on its own.
Even if none had been blown off from the impact (which is ludicrous), the parts of the trusses not covered would've heated up quickly in any fire, and that's where plastic deformation would've concentrated.
If you apply a torch to a long steel chain, it isn't the average temperature of the chain that determines the strength of the chain.
So too, if one part of a truss gets heated to its critical temperature (about 650C), it starts stretching immediately. The average temperature of the truss is irrelevant.
Thermal conductivity of steel isn't even as good as cast iron, BTW, and I recall my grandmother frying chicken in a cast iron skillet and she'd grab the handle barehanded and not get burned. So the steel doesn't "act like a heat sink" as you've previously asserted without justification.
Here is a link to a table of common materials' thermal conductivity:
http://www.engineeringtoolbox.com/thermal-...vity-d_429.html
It isn't the averages that concern me, as I've explained before, it's the extremes that dominate the phenomenology.
On-average, the spray-on insulation used on the Columbia worked precisely as the tests/manufacturer's specs indicated that it would.
On-average, less than 0.08% of the O-ring seals on the Shuttle's boosters have failed, to-date.
Further evidence supporting the Invisible Godzilla theory.
wcelliott you are a JOKE. NIST did tests that was almost 4 hours long in 700C with double the weight known to have been on the actual floors. And they did not come close to collapse!!!. How many times do you want me to say it?. [removed] And since when did 700C fires make structural steel collapse?
And one more thing they was using less fireproofing on the assemblies than was known to be on the steel in the Twin Towers, and despite that they where loading the floors with double the weight known to have been on the actual floors, it could not get an assembly to collapse
adoucette
wcelliott you are a JOKE. NIST did tests that was almost 4 hours long in 700C with double the weight known to have been on the actual floors. And they did not come close to collapse!!!. How many times do you want me to say it?. [removed] And since when did 700C fires make structural steel collapse?
And one more thing they was using less fireproofing on the assemblies than was known to be on the steel in the Twin Towers, and despite that they where loading the floors with double the weight known to have been on the actual floors, it could not get an assembly to collapse
adoucette
Besides the several simulations of the damage, there is the fact that NO ONE survived from ABOVE the impact floors on WTC 1.
They have NO PROOF that the fires did any damage to the CORE columns.
And heating of core columns would be especially difficult given the apparently poor ventilation of the core regions, being further from any air supply.
And since when did 700C fires make structural steel collapse?
When the buildings were first impacted by a high speed jet.
You want to compare run of the mill building fires with the WTC towers by assuming the planes did no damage.
But that is obviously not true.
I suggest you take a look at the recent Purdue visualization of the impact.
Maybe then you will start to realize what you are leaving out of your simplistic analysis.
Like your continual point about the oven tests.
The tests were of INSULATED trusses, and they DID SAG, which is the SAME as what NIST showed in their models. The trusses SAGGED, they didn't fail. So pointing out they didn't fail doesn't mean SQUAT.
Arthur
Pinhead - You can say it a million times, but you're still wrong.
You seem to think that NIST ran the first and only test of the strength of steel in the history of mankind.
WRONG.
Look closely at that link I provided (three times, so far, and you apparently haven't looked at it once).
It starts out "engineeringtoolbox.com". Engineers rely on this sort of data, produced by and for engineers.
The curves and data show that steel loses over half its strength at 650C. Beyond that, the steel gets PLASTIC, which means that it changes shape irreversibly.
That's why blacksmiths heat up steel before they work it, if they didn't get it hot, they could hammer on it all day long without changing its shape.
The trusses got this hot (maybe hotter) and they CHANGED SHAPE!!! At that point, all assumptions that the design was based on go out the window.
Just look at the site and STFU.
NIST admits that only a small percentage of columns were severed: 14% in WTC 1 and 15% WTC 2. This is nowhere near the the number of columns that the designers claimed could have been removed without causing a problem.
% of columns isn't the issue, its mainly Core columns that were the issue and they aren't the same.
The REAL issue is that the loss of core columns caused the top to tilt.
QUOTE
2. How much were loads redistributed?
NIST admits that the web of steel formed by interlocking perimeter columns and spandrel plates were efficient at redistributing loads around the impact punctures. It estimates that loads on some columns increased by up to 35% while loads on other columns decreased by 20%. The increased loads are nowhere near those the designers claimed the columns could handle: increases of 2000% above the design live loads.
NIST admits that the web of steel formed by interlocking perimeter columns and spandrel plates were efficient at redistributing loads around the impact punctures. It estimates that loads on some columns increased by up to 35% while loads on other columns decreased by 20%. The increased loads are nowhere near those the designers claimed the columns could handle: increases of 2000% above the design live loads.
The designers didn't make that claim, but even so, the quote was only about increases in LIVE loads and it pertained only to the perimeter columns and had to do with dealing with WIND loads, which of course were NOT the issue on 9/11.
QUOTE (->
| QUOTE |
| 2. How much were loads redistributed? NIST admits that the web of steel formed by interlocking perimeter columns and spandrel plates were efficient at redistributing loads around the impact punctures. It estimates that loads on some columns increased by up to 35% while loads on other columns decreased by 20%. The increased loads are nowhere near those the designers claimed the columns could handle: increases of 2000% above the design live loads. |
The designers didn't make that claim, but even so, the quote was only about increases in LIVE loads and it pertained only to the perimeter columns and had to do with dealing with WIND loads, which of course were NOT the issue on 9/11.
3. Fireproofing widely dislodged?
Yes, and we dealt with this idocy from Ryan and Wierzbicki just recently in this thread. Do a search. Learn something.
Arthur
QUOTE (newton+Jun 3 2007, 02:03 AM)
QUOTE
Myeloma is a relatively uncommon cancer. The American Cancer Society estimates that about 19,900 new cases of multiple myeloma (10,960 in men and 8,940 in women) will be diagnosed during 2007.
About 10,790 Americans (5,550 men and 5,240 women) are expected to die of multiple myeloma in 2007.
The 5-year relative survival rate for multiple myeloma is around 33%. Survival is higher in younger people and lower in the elderly. Of course, 5-year survival rates are based on patients diagnosed and initially treated more than 5 years ago. The recent improvements in treatment may result in a more favorable outlook for recently diagnosed patients.
The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Five-year survival rates are used to produce a standard way of discussing prognosis. Of course, many people live much longer than 5 years. Five-year relative survival rates exclude patients dying of other diseases. This means that anyone who died of another cause, such as heart disease, is not counted.
About 10,790 Americans (5,550 men and 5,240 women) are expected to die of multiple myeloma in 2007.
The 5-year relative survival rate for multiple myeloma is around 33%. Survival is higher in younger people and lower in the elderly. Of course, 5-year survival rates are based on patients diagnosed and initially treated more than 5 years ago. The recent improvements in treatment may result in a more favorable outlook for recently diagnosed patients.
The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Five-year survival rates are used to produce a standard way of discussing prognosis. Of course, many people live much longer than 5 years. Five-year relative survival rates exclude patients dying of other diseases. This means that anyone who died of another cause, such as heart disease, is not counted.
no, really.
QUOTE (->
| QUOTE |
| Myeloma is a relatively uncommon cancer. The American Cancer Society estimates that about 19,900 new cases of multiple myeloma (10,960 in men and 8,940 in women) will be diagnosed during 2007. About 10,790 Americans (5,550 men and 5,240 women) are expected to die of multiple myeloma in 2007. The 5-year relative survival rate for multiple myeloma is around 33%. Survival is higher in younger people and lower in the elderly. Of course, 5-year survival rates are based on patients diagnosed and initially treated more than 5 years ago. The recent improvements in treatment may result in a more favorable outlook for recently diagnosed patients. The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Five-year survival rates are used to produce a standard way of discussing prognosis. Of course, many people live much longer than 5 years. Five-year relative survival rates exclude patients dying of other diseases. This means that anyone who died of another cause, such as heart disease, is not counted. |
no, really.
Radiation Exposure
Exposure to radioactivity has been suggested as a risk factor but accounts for a very small number of cases.
all of a sudden, ground zero workers are all getting the same 'relatively uncommon cancer', and it's onset is rapid.
QUOTE
Occupational Exposure
Some studies have suggested that workers in certain petroleum-related industries may be at a higher risk.
Some studies have suggested that workers in certain petroleum-related industries may be at a higher risk.
the difference between radiation , and toxic dust/fumes, is radiation's effects are far faster.
QUOTE (->
| QUOTE |
| Occupational Exposure Some studies have suggested that workers in certain petroleum-related industries may be at a higher risk. |
the difference between radiation , and toxic dust/fumes, is radiation's effects are far faster.
Types of Cancer Associated With Ionizing Radiation
Leukemia was at one time thought to be the major cancer to arise from high-dose radiation exposure, based on the experience with people exposed to the atomic blasts in Japan. It is now known that other cancers can result from radiation exposure, although they may take longer to develop (usually at least 10 to 15 years). Leukemias, by contrast, begin appearing as early as 2 years after acute radiation exposure.
Studies of the survivors of the atomic blasts have demonstrated that high-dose radiation (at least 100cGy) increases the risk of developing several types of cancer.
* For these survivors, the risk of developing leukemia is five and a half times greater than in the general public. Children appear to be twice as sensitive as adults to the leukemia-causing effects of radiation, and unborn children exposed to radiation in the uterus are even more sensitive.
* The risk for developing any type of cancer in those highly exposed to an atomic blast is about 50% higher than the risk in those not exposed.
* Female breast cancer risk is more than twice as high as normal, and women who are exposed when under the age of 20 are found to be at higher risk than older women.
* The risk of developing lung cancer is 50% higher, and the risk for multiple myeloma is more than twice as high as in the general population.
QUOTE (wcelliott+Jun 3 2007, 10:33 AM)
Didn't you know? Nobody dies of natural causes, that's just how the CIA/MiB make people disappear.
actually, heart attacks are much easier, and immediate.
QUOTE
the difference between radiation , and toxic dust/fumes, is radiation's effects are far faster.
I'm loving the dark innuendo, but I just wish you'd actually *say* what you keep implying.
You think they, excuse me, They, **nuked** the WTC, don't you?
C'mon, say it. Spit it out.
It isn't like you could lose any more credibility than you already have (trusting Osama bin Laden's word while accusing NIST scientists of being dishonest).
Or, maybe the concrete dust got inhaled.
http://greenwood.cr.usgs.gov/energy/factsh.../FS-163-97.html
" Fly ash is commonly used as an additive to concrete building products, but the radioactivity of typical fly ash is not significantly different from that of more conventional concrete additives or other building materials such as granite or red brick. One extreme calculation that assumed high proportions of fly-ash-rich concrete in a residence suggested a dose enhancement, compared to normal concrete, of 3 percent of the natural environmental radiation.
Another consideration is that low-density, fly-ash-rich concrete products may be a source of radon gas. Direct measurement of this contribution to indoor radon is complicated by the much larger contribution from underlying soil and rock (see fig. 4). The emanation of radon gas from fly ash is less than from natural soil of similar uranium content. Present calculations indicate that concrete building products of all types contribute less than 10 percent of the total indoor radon. "
Then again, concrete as a slab in the basement is a slightly different situation than concrete dust in the lungs.
QUOTE
Thus we could say that WTC 2 actually started to tip over as soon as it was hit by an aircraft, but the tipping was not noticeable because the average angular velocity was only about 1° per hour or 0.0003° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1.
At one minute before collapse the angular velocity of the upper section of WTC 2 would have increased to about 0.03° s-1.
Thank you, NF, for this.
If this data were plotted versus time for each of the two towers, I think this plot alone would serve to sink any and all CD theories.
I, too, expected that the angle-rate started at-impact and proceeded to grow monotonically until the collapse event itself. If the plot were sufficiently fine-grained (instead of a point here at one value and a point there at another and a straight line interpolated in between) it could be seen that the lack of a discontinuity in the angle-rate plot means that no CD-explosion occurred. A CD explosion would necessarily result in an abrupt change in the angle-rate, so if the angle-rate curve is continuous, then there were no discrete events contributing to the buildings' collapse.
I appreciate the fact that this additional proof should be unnecessary, but we're clearly dealing with people who aren't open to the explanations provided to-date, and this argument can be made simple enough that perhaps even Malmo could follow the logic.
bombed out buildings...
QUOTE
% of columns isn't the issue, its mainly Core columns that were the issue and they aren't the same.
'Where are the PROOF that the core was damage????
And no i dont need to do a search. NIST proves in the shotgun test that the fireproofing couldnt have been destroyed like they say. And fire proofing or not under 45 min doesnt matter!!! the fires wasnt hot enough to make the steel collapse so stop the BS. 700C in 4 hours CANT WEAKEN THE STEEL AND MAKE IT COLLAPSE. Do you understand?????
collapses...
Under the title "Writings of a Finnish Military Expert on 9/11" some very interesting theories about the WTC collapse have become a common place on the internet
www.saunalahti.fi/wtc2001/military.htm
By 2006-06-13 another Finn, Mr. Antti Partanen, bothered to debunk the H-bomb theory and made his point.
www.kolumbus.fi/totuus/doc/wtcatom.html
Most interesting even, the anonymous Finnish expert bothered to reply and went deeper into the subject with more arguments which everyone should seriously take into account. So, please do read this:
www.saunalahti.fi/wtc2001/H-device.htm
www.saunalahti.fi/wtc2001/military.htm
By 2006-06-13 another Finn, Mr. Antti Partanen, bothered to debunk the H-bomb theory and made his point.
www.kolumbus.fi/totuus/doc/wtcatom.html
Most interesting even, the anonymous Finnish expert bothered to reply and went deeper into the subject with more arguments which everyone should seriously take into account. So, please do read this:
www.saunalahti.fi/wtc2001/H-device.htm
tipped buildings.....
QUOTE (Malmoesoldier+Jun 3 2007, 11:47 AM)
'
Where are the PROOF that the core was damage????
Besides the several simulations of the damage, there is the fact that NO ONE survived from ABOVE the impact floors on WTC 1.
Arthur
Where are the PROOF that the core was damage????
Besides the several simulations of the damage, there is the fact that NO ONE survived from ABOVE the impact floors on WTC 1.
Arthur
QUOTE
so stop the BS. 700C in 4 hours CANT WEAKEN THE STEEL AND MAKE IT COLLAPSE. Do you understand?????
http://www.engineeringtoolbox.com/young-modulus-d_773.html
Read that and tell us all how strong steel is at 700C.
Here's a hint: the table doesn't even go up to 700C, because it's already beyond steel's critical temperature, where force applied just makes the steel undergo plastic deformation.
"Yield strength
Yield strength, or the yield point, is defined in engineering as the amount of strain that a material can undergo before moving from elastic deformation into plastic deformation."
http://www.engineeringtoolbox.com/young-modulus-d_417.html
This is the temperature that blacksmiths heat up their steel to when they want to bend/form it to shape.
Idiot.
Newton, the WTC doesn't look like those buildings because those buildings weren't built like the WTC, nor did they collapse under the same conditions.
I could as easily post shots of the buildings that Godzilla kicked-over, they wouldn't have any more relevance to the discussion than your pictures do.
Please address the issue that I've raised a couple of times already. Why is it that you believe Osama bin Laden when he claimed he wasn't responsible for the attacks, while you feel that the scientists at NIST are lying?
I could as easily post shots of the buildings that Godzilla kicked-over, they wouldn't have any more relevance to the discussion than your pictures do.
Please address the issue that I've raised a couple of times already. Why is it that you believe Osama bin Laden when he claimed he wasn't responsible for the attacks, while you feel that the scientists at NIST are lying?
right.
i don't "believe" osama. i don't even know him.
i do know that the famous video of him confessing is not him, and so, the fact that someone faked it, and the media ran with it, indicates a cover-up, and also indicates that there is no actual osama confession. so, why do you believe he did it?
the fact that the FBI has no evidence connecting osama to 911 might be another clue.
i don't believe NIST, because they didn't do the job they set out to do, and because their own empirical evidence(vs. sims) refute their own conclusion.
the steel measured was not that hot. only four pieces tested out of 170, or something, showed ANY signs of exposure to heat. the steel that was tested held up.
the perimeters are cooler, because of their direct contact with air, and any sagging trusses which are now cooling, are still going to be hotter/weaker than the perimeter by far.
i don't "believe" osama. i don't even know him.
i do know that the famous video of him confessing is not him, and so, the fact that someone faked it, and the media ran with it, indicates a cover-up, and also indicates that there is no actual osama confession. so, why do you believe he did it?
the fact that the FBI has no evidence connecting osama to 911 might be another clue.
i don't believe NIST, because they didn't do the job they set out to do, and because their own empirical evidence(vs. sims) refute their own conclusion.
the steel measured was not that hot. only four pieces tested out of 170, or something, showed ANY signs of exposure to heat. the steel that was tested held up.
the perimeters are cooler, because of their direct contact with air, and any sagging trusses which are now cooling, are still going to be hotter/weaker than the perimeter by far.
QUOTE
Most interesting even, the anonymous Finnish expert bothered to reply and went deeper into the subject with more arguments which everyone should seriously take into account. So, please do read this:
I have an alternative explanation that works even better.
The MiB, using alien technology from the Roswell crash, discovered a way to make Godzilla invisible.
QUOTE (wcelliott+Jun 3 2007, 06:40 PM)
I have an alternative explanation that works even better.
The MiB, using alien technology from the Roswell crash, discovered a way to make Godzilla invisible.
i'll look in to this.
anything's possible.
QUOTE
NIST proves in the shotgun test that the fireproofing couldnt have been destroyed like they say
I've seen actual photographs of the sprayed-on insulation on the steel trusses of at the WTC taken during routine building inspections, and the insulation coverage was spotty, at best. The spray-on fireproofing had a natural tendency to *fall off* on its own.
Even if none had been blown off from the impact (which is ludicrous), the parts of the trusses not covered would've heated up quickly in any fire, and that's where plastic deformation would've concentrated.
If you apply a torch to a long steel chain, it isn't the average temperature of the chain that determines the strength of the chain.
So too, if one part of a truss gets heated to its critical temperature (about 650C), it starts stretching immediately. The average temperature of the truss is irrelevant.
Thermal conductivity of steel isn't even as good as cast iron, BTW, and I recall my grandmother frying chicken in a cast iron skillet and she'd grab the handle barehanded and not get burned. So the steel doesn't "act like a heat sink" as you've previously asserted without justification.
Here is a link to a table of common materials' thermal conductivity:
http://www.engineeringtoolbox.com/thermal-...vity-d_429.html
SFRM was upgraded in the impact zone of the wtc 1 and part of wtc 2:
…“thermal protection was upgraded…in WTC 1, floors 92-100, and 102…and WTC 2, floors 77, 78, 88, 89, 92, 96 and 97.” (NCSTAR 1-6 p20, para1)
“The entire impact zone for Tower 1 (92-99) was upgraded with 1-1/2” spray-on fireproofing.” (NCSTAR 1-6 p25, para1)
“The overall average thickness determined from the 256 individual measurements was found to be 2.5 in. with a standard deviation of 0.6 in. Thus, the average SFRM thickness on the upgraded upper floors appears to be greater than that estimated from photographs taken on the upgraded lower floor.” (NCSTAR 1-6 p25, para3)
…“the average of the adhesive and cohesive strengths was found to be 409 psf for the ¾ in. SFRM, and the average is 622 psf for the 1-1/2 in. SFRM. These values are considerably greater than the manufacturer’s published strength of 295 psf, obtained using the ASTM E 736 method under laboratory conditions.” (NCSTAR 1-6 p35, para7)
The NIST WTC Investigation--. How Real Was The Simulation? A review of NIST NCSTAR 1. By Eric Douglas
www.nistreview.org/NCSTAR1-REVIEW-DOUGLAS.pdf (p.6)
…“thermal protection was upgraded…in WTC 1, floors 92-100, and 102…and WTC 2, floors 77, 78, 88, 89, 92, 96 and 97.” (NCSTAR 1-6 p20, para1)
“The entire impact zone for Tower 1 (92-99) was upgraded with 1-1/2” spray-on fireproofing.” (NCSTAR 1-6 p25, para1)
“The overall average thickness determined from the 256 individual measurements was found to be 2.5 in. with a standard deviation of 0.6 in. Thus, the average SFRM thickness on the upgraded upper floors appears to be greater than that estimated from photographs taken on the upgraded lower floor.” (NCSTAR 1-6 p25, para3)
…“the average of the adhesive and cohesive strengths was found to be 409 psf for the ¾ in. SFRM, and the average is 622 psf for the 1-1/2 in. SFRM. These values are considerably greater than the manufacturer’s published strength of 295 psf, obtained using the ASTM E 736 method under laboratory conditions.” (NCSTAR 1-6 p35, para7)
The NIST WTC Investigation--. How Real Was The Simulation? A review of NIST NCSTAR 1. By Eric Douglas
www.nistreview.org/NCSTAR1-REVIEW-DOUGLAS.pdf (p.6)
QUOTE (NEU-FONZE+May 28 2007, 06:31 PM)
Shagster:
I also tried my program on WTC 7. I used a mass of 40 floors falling on 7 floors. I assumed the mass of the 40 story block was 40/110 of the mass of one twin tower. Since I used 510,000 tonnes for WTC 1 & 2, this gave 185,455 tonnes for the falling mass which is much heavier than the upper falling mass of either WTC 1 or 2..... For E1 I used 1.8 GJ to allow for strong floors. I have not tried varying E1 yet although this is simple enough to do.
These parameters gave a collapse time of 6.56 seconds. Interestingly, the last part of the collapse slows considerably, rather than accelerates as for WTC 1 & 2 because, for WTC 7, the "hammer" is getting smaller and smaller!
My calculations are giving a similar duration to yours, 6.6 vs. 6.56. I've calculated it with varying E1 values that are about 4 times higher at the ground level compared with the upper floors. It doesn't affect the overall duration much. I can post more details if you are interested. I haven't tried it yet with a story mass that varies as a function of height. I've also used the differential equation approach and it gives the same collapse duration as the discrete model.
In a continuum model, the front always 'poops out' near the end of a crush-up collapse since the front position is modeled down to infinitesimal advances. In the real world, there are stories of finite height and the last stories near the top may get crushed too, depending on the value of E1 and other parameters. Theoretically, it's possible to get some idea of the value of E1 in a crush-up by noting at which story the collapse pooped out, not knowing anything about the collapse rate or duration.
I also tried my program on WTC 7. I used a mass of 40 floors falling on 7 floors. I assumed the mass of the 40 story block was 40/110 of the mass of one twin tower. Since I used 510,000 tonnes for WTC 1 & 2, this gave 185,455 tonnes for the falling mass which is much heavier than the upper falling mass of either WTC 1 or 2..... For E1 I used 1.8 GJ to allow for strong floors. I have not tried varying E1 yet although this is simple enough to do.
These parameters gave a collapse time of 6.56 seconds. Interestingly, the last part of the collapse slows considerably, rather than accelerates as for WTC 1 & 2 because, for WTC 7, the "hammer" is getting smaller and smaller!
My calculations are giving a similar duration to yours, 6.6 vs. 6.56. I've calculated it with varying E1 values that are about 4 times higher at the ground level compared with the upper floors. It doesn't affect the overall duration much. I can post more details if you are interested. I haven't tried it yet with a story mass that varies as a function of height. I've also used the differential equation approach and it gives the same collapse duration as the discrete model.
In a continuum model, the front always 'poops out' near the end of a crush-up collapse since the front position is modeled down to infinitesimal advances. In the real world, there are stories of finite height and the last stories near the top may get crushed too, depending on the value of E1 and other parameters. Theoretically, it's possible to get some idea of the value of E1 in a crush-up by noting at which story the collapse pooped out, not knowing anything about the collapse rate or duration.
QUOTE (wcelliott+Jun 3 2007, 02:00 AM)
I mentioned earlier that the best way to measure the descent-rate leading up to the collapse would be to measure the tilt-angle-rate as a function of time.
... this might make a nice appendix to your paper, and it shouldn't take too much additional hard work, especially compared to what you've already put into this very-well-written/well-thought-out paper.
NEU-FONZE earlier measured and posted drop data for both towers. For WTC 1, the tilt was first to the north, according to NIST. (I suppose this is due to the hole in the exterior wall. But once the south wall began to buckle, the tilt would be some tiny angle to the south. When the south wall, immediately followed by the east and west walls buckled, the top, hinged on the north wall tilted up to 8 degrees directly to the south before the hinge broke. Using NEU-FONZE's data, I determined the angles for the first 1.2 seconds, to determine that the north wall broke between 1.0 and 1.2 seconds. The surprise for me was how fast the angle increased between 0.8 seconds (about 4 arc-degrees) and 1.0 seconds (about 6 arc-degrees).
Those pushing CD have no explanation for the bowing in observed on three walls of WTC 1, up to 20 minutes before collapse initiation. This bowing-in then obviously induced some small tilt angle, but that might actually be difficult to measure, whereas the bowing-in was measured by NIST. Using that, I suppose you could calculate to tilt angle if you somehow thought that important.
Thank you for the kind words. The paper is up to the page limit, so nothing can be added.
... this might make a nice appendix to your paper, and it shouldn't take too much additional hard work, especially compared to what you've already put into this very-well-written/well-thought-out paper.
NEU-FONZE earlier measured and posted drop data for both towers. For WTC 1, the tilt was first to the north, according to NIST. (I suppose this is due to the hole in the exterior wall. But once the south wall began to buckle, the tilt would be some tiny angle to the south. When the south wall, immediately followed by the east and west walls buckled, the top, hinged on the north wall tilted up to 8 degrees directly to the south before the hinge broke. Using NEU-FONZE's data, I determined the angles for the first 1.2 seconds, to determine that the north wall broke between 1.0 and 1.2 seconds. The surprise for me was how fast the angle increased between 0.8 seconds (about 4 arc-degrees) and 1.0 seconds (about 6 arc-degrees).
Those pushing CD have no explanation for the bowing in observed on three walls of WTC 1, up to 20 minutes before collapse initiation. This bowing-in then obviously induced some small tilt angle, but that might actually be difficult to measure, whereas the bowing-in was measured by NIST. Using that, I suppose you could calculate to tilt angle if you somehow thought that important.
Thank you for the kind words. The paper is up to the page limit, so nothing can be added.
QUOTE (3bodyproblem+Jun 3 2007, 04:50 AM)
After looking at numerous videos it appears the floor collapse precedes the upper section by 3 stories, at least in the first few seconds.
There is no reason to believe this did not continue for the entire crush down.
The upper sections decent seems to have been only impeded by the core (It is my opinion that the exterior columns did little to impede the upper section during the collapse.
(1) I assume you are considering WTC 2.
(2) Yes, there is. Pierre-Normand addressed this point.
(3) The top block is sitting on top of the crushed mass, where-ever that is. The energy drain of breaking the connections in the walls would slow the collapse. For WTC 1, it is clear from the geometry that the upper portions of the exterior walls wedged inside the lower portions, helping to start building the crushing front.
(4) By definition, zone B is the entire crushed portion. You could consider dividing this into zones Bf and Bc if you want.
There is no reason to believe this did not continue for the entire crush down.
The upper sections decent seems to have been only impeded by the core (It is my opinion that the exterior columns did little to impede the upper section during the collapse.
(1) I assume you are considering WTC 2.
(2) Yes, there is. Pierre-Normand addressed this point.
(3) The top block is sitting on top of the crushed mass, where-ever that is. The energy drain of breaking the connections in the walls would slow the collapse. For WTC 1, it is clear from the geometry that the upper portions of the exterior walls wedged inside the lower portions, helping to start building the crushing front.
(4) By definition, zone B is the entire crushed portion. You could consider dividing this into zones Bf and Bc if you want.
QUOTE (reasonwhy+Jun 3 2007, 02:34 AM)
( even with the video evidence of the core standing momentarily)
This was only a small fragment of the entire core. Jeese.
This was only a small fragment of the entire core. Jeese.
QUOTE
…“the average of the adhesive and cohesive strengths was found to be 409 psf
It isn't the averages that concern me, as I've explained before, it's the extremes that dominate the phenomenology.
On-average, the spray-on insulation used on the Columbia worked precisely as the tests/manufacturer's specs indicated that it would.
On-average, less than 0.08% of the O-ring seals on the Shuttle's boosters have failed, to-date.
QUOTE
Those pushing CD have no explanation for the bowing in observed on three walls of WTC 1, up to 20 minutes before collapse initiation.
Further evidence supporting the Invisible Godzilla theory.
QUOTE
Read that and tell us all how strong steel is at 700C.
wcelliott you are a JOKE. NIST did tests that was almost 4 hours long in 700C with double the weight known to have been on the actual floors. And they did not come close to collapse!!!. How many times do you want me to say it?. [removed] And since when did 700C fires make structural steel collapse?
And one more thing they was using less fireproofing on the assemblies than was known to be on the steel in the Twin Towers, and despite that they where loading the floors with double the weight known to have been on the actual floors, it could not get an assembly to collapse
adoucette
QUOTE (->
| QUOTE |
| Read that and tell us all how strong steel is at 700C. |
wcelliott you are a JOKE. NIST did tests that was almost 4 hours long in 700C with double the weight known to have been on the actual floors. And they did not come close to collapse!!!. How many times do you want me to say it?. [removed] And since when did 700C fires make structural steel collapse?
And one more thing they was using less fireproofing on the assemblies than was known to be on the steel in the Twin Towers, and despite that they where loading the floors with double the weight known to have been on the actual floors, it could not get an assembly to collapse
adoucette
Besides the several simulations of the damage, there is the fact that NO ONE survived from ABOVE the impact floors on WTC 1.
They have NO PROOF that the fires did any damage to the CORE columns.
And heating of core columns would be especially difficult given the apparently poor ventilation of the core regions, being further from any air supply.
QUOTE (3bodyproblem+May 31 2007, 09:56 PM)
The structural integrity of the WTC relied on secure truss connections to maintain the weight on the exterior walls. Once the geometry was disturbed there was significantly less resistance to the global collapse. Thank you for hearing me.
That's the opposite of redundancy. The way the towers were designed, the overall structure became more unstable as portions of the structure deteriorated during the fire.
Engineers should learn some lessons from some of the features observed in the Broadgate fire where structural redundancy (intermediate columns, moment resisting floor connections, etc) helped prevent the structure from collapsing.
That's the opposite of redundancy. The way the towers were designed, the overall structure became more unstable as portions of the structure deteriorated during the fire.
Engineers should learn some lessons from some of the features observed in the Broadgate fire where structural redundancy (intermediate columns, moment resisting floor connections, etc) helped prevent the structure from collapsing.
In the mid-1990s British Steel and the Building Research Establishment performed a series of six experiments at Cardington to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beams reaching 800-900º C (1,500-1,700º F) in three of the tests (well above the traditionally assumed critical temperature of 600º C (1,100º F), no collapse was observed in any of the six experiments). FEMA
This article I'm reading sheds some light on the WTC first responders health, and who should be blamed.
Giuliani: Worse Than Bush
Giuliani: Worse Than Bush
QUOTE
While the mayor himself flew out of New York on a magic carpet, thousands of cash-strapped cops, firemen and city workers involved with the cleanup at the World Trade Center were developing cancers and infections and mysterious respiratory ailments like the "WTC cough." This is the dirty little secret lurking underneath Rudy's 9/11 hero image -- the most egregious example of his willingness to shape public policy to suit his donors. While the cleanup effort at the Pentagon was turned over to federal agencies like OSHA, which quickly sealed off the site and required relief workers to wear hazmat suits, the World Trade Center cleanup was handed over to Giuliani. The city's Department of Design and Construction (DDC) promptly farmed out the waste-clearing effort to a smattering of politically connected companies, including Bechtel, Bovis and AMEC construction.
The mayor pledged to reopen downtown in no time, and internal DDC memos indicate that the cleanup was directed at a breakneck pace. One memo to DDC chief Michael Burton warned, "Project management appears to only address safety issues when convenient for the schedule of the project." Burton, however, had his own priorities: He threatened to fire contractors if "the highest level of efficiency is not maintained."
Although respiratory-mask use was mandatory, the city allowed a macho culture to develop on the site: Even the mayor himself showed up without a mask. By October, it was estimated, masks were being worn on site as little as twenty-nine percent of the time. Rudy proclaimed that there were "no significant problems" with the air at the World Trade Center. But there was something wrong with the air: It was one of the most dangerous toxic-waste sites in human history, full of everything from benzene to asbestos and PCBs to dioxin (the active ingredient in Agent Orange). Since the cleanup ended, police and firefighters have reported a host of serious illnesses -- respiratory ailments like sarcoidosis; leukemia and lymphoma and other cancers; and immune-system problems.
The mayor pledged to reopen downtown in no time, and internal DDC memos indicate that the cleanup was directed at a breakneck pace. One memo to DDC chief Michael Burton warned, "Project management appears to only address safety issues when convenient for the schedule of the project." Burton, however, had his own priorities: He threatened to fire contractors if "the highest level of efficiency is not maintained."
Although respiratory-mask use was mandatory, the city allowed a macho culture to develop on the site: Even the mayor himself showed up without a mask. By October, it was estimated, masks were being worn on site as little as twenty-nine percent of the time. Rudy proclaimed that there were "no significant problems" with the air at the World Trade Center. But there was something wrong with the air: It was one of the most dangerous toxic-waste sites in human history, full of everything from benzene to asbestos and PCBs to dioxin (the active ingredient in Agent Orange). Since the cleanup ended, police and firefighters have reported a host of serious illnesses -- respiratory ailments like sarcoidosis; leukemia and lymphoma and other cancers; and immune-system problems.
QUOTE (Malmoesoldier+Jun 3 2007, 03:37 PM)
And since when did 700C fires make structural steel collapse?
When the buildings were first impacted by a high speed jet.
You want to compare run of the mill building fires with the WTC towers by assuming the planes did no damage.
But that is obviously not true.
I suggest you take a look at the recent Purdue visualization of the impact.
Maybe then you will start to realize what you are leaving out of your simplistic analysis.
Like your continual point about the oven tests.
The tests were of INSULATED trusses, and they DID SAG, which is the SAME as what NIST showed in their models. The trusses SAGGED, they didn't fail. So pointing out they didn't fail doesn't mean SQUAT.
Arthur
QUOTE (shagster+Jun 3 2007, 08:41 PM)
That's the opposite of redundancy. The way the towers were designed, the overall structure became more unstable as portions of the structure deteriorated during the fire.
Engineers should learn some lessons from some of the features observed in the Broadgate fire where structural redundancy (intermediate columns, moment resisting floor connections, etc) helped prevent the structure from collapsing.
1) Is it the opposite? I still maintain that the truss connections were vital in maintaining the geometry of the core and exterior. It would seem that their disconnections predicated the collapse at least in WTC 2.
2) Agreed
Engineers should learn some lessons from some of the features observed in the Broadgate fire where structural redundancy (intermediate columns, moment resisting floor connections, etc) helped prevent the structure from collapsing.
1) Is it the opposite? I still maintain that the truss connections were vital in maintaining the geometry of the core and exterior. It would seem that their disconnections predicated the collapse at least in WTC 2.
2) Agreed
Alan:
Yes! For more Giuliani horror stories about his real role in 9/11 try reading Grand Illusion by Barrett and Collins. Chapter 7 on the firefighter's radios is especially disturbing....
Yes! For more Giuliani horror stories about his real role in 9/11 try reading Grand Illusion by Barrett and Collins. Chapter 7 on the firefighter's radios is especially disturbing....
QUOTE
How many times do you want me to say it?.
Pinhead - You can say it a million times, but you're still wrong.
You seem to think that NIST ran the first and only test of the strength of steel in the history of mankind.
WRONG.
Look closely at that link I provided (three times, so far, and you apparently haven't looked at it once).
It starts out "engineeringtoolbox.com". Engineers rely on this sort of data, produced by and for engineers.
The curves and data show that steel loses over half its strength at 650C. Beyond that, the steel gets PLASTIC, which means that it changes shape irreversibly.
That's why blacksmiths heat up steel before they work it, if they didn't get it hot, they could hammer on it all day long without changing its shape.
The trusses got this hot (maybe hotter) and they CHANGED SHAPE!!! At that point, all assumptions that the design was based on go out the window.
Just look at the site and STFU.
QUOTE (David B. Benson+Jun 3 2007, 08:11 PM)
(1) I assume you are considering WTC 2.
(2) Yes, there is. Pierre-Normand addressed this point.
(3) The top block is sitting on top of the crushed mass, where-ever that is. The energy drain of breaking the connections in the walls would slow the collapse. For WTC 1, it is clear from the geometry that the upper portions of the exterior walls wedged inside the lower portions, helping to start building the crushing front.
(4) By definition, zone B is the entire crushed portion. You could consider dividing this into zones Bf and Bc if you want.
1) Yep.
2) I was alerted to this last night and posted a response to Pierre this morning. I agree with what he said, but offered an alternate explanation. I am not entirely convinced of its validity, but I think I did present a reasonable counter argument.
3) Yes, I agree with what you are saying, and I think I did account for it in my postulate. I believe there is something to be said for the idea of mass from Zone B being ejected once it reaches a critical mass proportional to the plate thickness of the exterior columns.
I am now under the impression that the collapse mechanism would be more appropriately modeled using chaos theory.
(2) Yes, there is. Pierre-Normand addressed this point.
(3) The top block is sitting on top of the crushed mass, where-ever that is. The energy drain of breaking the connections in the walls would slow the collapse. For WTC 1, it is clear from the geometry that the upper portions of the exterior walls wedged inside the lower portions, helping to start building the crushing front.
(4) By definition, zone B is the entire crushed portion. You could consider dividing this into zones Bf and Bc if you want.
1) Yep.
2) I was alerted to this last night and posted a response to Pierre this morning. I agree with what he said, but offered an alternate explanation. I am not entirely convinced of its validity, but I think I did present a reasonable counter argument.
3) Yes, I agree with what you are saying, and I think I did account for it in my postulate. I believe there is something to be said for the idea of mass from Zone B being ejected once it reaches a critical mass proportional to the plate thickness of the exterior columns.
I am now under the impression that the collapse mechanism would be more appropriately modeled using chaos theory.
[removed]
QUOTE (NEU-FONZE+Jun 3 2007, 03:07 PM)
Chapter 7 on the firefighter's radios is especially disturbing....
Yeah, I've read some about the radios, and I bet what you recomend goes into more detail. That article I linked touched on it, on an earlier page. In particular, it mentions lives could have been saved if the firefighters could've heard the police helicopter's transmission about the tower starting to lean.
To Malmo... have you heard anything at all about that police helicopter,and their warning that the building was unstable and about to go? Can you describe some sort of CD that would produce those results? I mean, there is no super-slow-mo explosives that do that.
Yeah, I've read some about the radios, and I bet what you recomend goes into more detail. That article I linked touched on it, on an earlier page. In particular, it mentions lives could have been saved if the firefighters could've heard the police helicopter's transmission about the tower starting to lean.
To Malmo... have you heard anything at all about that police helicopter,and their warning that the building was unstable and about to go? Can you describe some sort of CD that would produce those results? I mean, there is no super-slow-mo explosives that do that.
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