Learn these diagrams before posting about steel.

[VTMechEngr]

Notice that steel does not have to melt to weaken enough to collapse due to heat.


Stress-strain Data for Grade 43A Steel at Elevated Temperatures.

Some helpful math for the true non-believer:



Basic stuff folks. Basic stuff.
More here:
http://www.umist.ac.uk/departments/civil/research/structures/strucfire/materialInFire/Steel/HotRolledCarbonSteel/mechanicalProperties.htm

NOTE: This is for the "steel had to melt or Steel doesn't get soft in a fire" People.

[LARED]

1. A for those that have the urge to really abuse themselves

http://www.amazon.com/exec/obidos/tg/detail/-/007072542X/002-9859016-9239206?v=glance

[philb]

7. I have reference books; but does yours explain the hundreds of witnesses

who witnessed explosions; even reporters at the site witnessed the explosions

Fox 5 News, a New York television channel, was able to catch on videotape a large white cloud billowing out near the base of the South Tower. The newsman commented: “There is an explosion at the base of the building….white smoke from the bottom …something has happened at the base of the building… then, another explosion.

[LARED]

13. Perhaps one of these days

you can explain why explosions being reported (there is a difference between reporting and witnessing) seem to be important to the CT'er demolition theory?

The buildings were impacted by jets at 400 to 500 miles per hour, there were extensive fires, extensive damage to the structure at many levels, and the frickin buildings collapsed.

Why are you surprised people reported explosions given the conditions. How do you expect a building under the above conditions to react? Why are you surprised that people call loud noises explosions?

[petgoat]

249. "there were extensive fires, extensive damage"

Then why did they send the firemen in at all? Because they didn't know
it was going to collapse. Nobody knew it. The only person who claims
that he knew was the guy who was awarded the contract to clean it up,
the guy from Controlled Demolition. And circumstantial evidence
suggests that he's lying.

[AZCat]

2. Aack!

Not SI!

Can't breathe... must... have... IP System...

...

[demodewd]

3. 2 questions

Why didn't the Madrid fire collapse?

This doesn't explain why the buildings went into virtual freefall only that it is possible that the fires would have initiated a collapse.

[pox americana]

4. look at all the fancy colors

and equations too. Let me guess, this is supposed to prove that a few floor trusses on the collision floors really did give way?

Um, I think we knew that from the pictures. Now how about explaining how the columns in the structural core chopped themselves into macaroni?

[janedoe]

9. I think he sold his Strength of Materials text book

Otherwise he'd know that A36 steel was more appropropriate to cite, especially because the WTC was not built to UK specs.
But neither address the questions, as you pointed out.

[LARED]

14. As our resident structural engineer and materials expert could

you expand on the differences between the A36 steel spec and the UK specification. Is A36 significantly stronger at elevated temps?

[VTMechEngr]

25. Specs on A36 steel.

To answer LARED's question, and criticism.

A36 steel. Want a graph? Plot it yourself.
At 300 F - Yield Strength is reduced to 99.50 % of rated yield
At 600 F - Yield Strength is reduced to 97.00 % of rated yield
At 900 F - Yield Strength is reduced to 81.50 % of rated yield
At 1000 F - Yield Strength is reduced to 74.00 % of rated yield
At 1200 F(650C) - Yield Strength is reduced to 39.00 % of rated yield
At 1472.00 F(800C) - Yield Strength is reduced to 18.92 % of rated yield
At 1800 F(982C) - Yield Strength is reduced to 9.00 % of rated yield

Steel melts at around ~1800C or 2500F (it changes by grade and additives)


You may also enjoy this: http://911research.wtc7.net/cache/wtc/analysis/fires/steel_fire_resistance.htm

[VTMechEngr]

16. I was just showing steel in general.

[VTMechEngr]

24. Well. I used UK specs because I couldn't find a graph in US Units

Not that the point would be any different.

[HughBeaumont]

12. And how the outer beams shot out several dozen feet horizontally . .

as proven by video footage and pics.

[carlvs]

15. I don't know...

Maybe having a mass weighing multiple tens of thousands of tons slamming into them from above might have had something to do with it... :sarcasm:

[pauldp]

18. Try hundreds of feet. More than 1 hundred yards actually. n/t

[HughBeaumont]

19. I stand corrected. And that debunks the sarcasm above -

Even a mass weighing several hundred tons wouldn't have the capability to shoot reinforced steel beams 100 yards horizontally BEFORE the mass reached the point of ejection. How come when the plane slammed into it, the building pretty much remained motionless and unbending?

[VTMechEngr]

22. Debunks? *rolls eyes*

Outer layers getting peeled off. Steel gets put under extreme load, shears apart and flies out. What you call an explosion, the thinking world calls a spring tension effect.

Ever notice a bow shoot an arrow. At those loads, steel bends like that too. And when it broke free?

I'm not Here to defend the * admin whom I detest, I'm here to cry that my political side has people who side with the Creationists when it comes to science ;(

[HughBeaumont]

27. Spring tension effect my ASS.

Look at the Madrid, Philadephia collapses. NO such thing happened with either of them. Both of their skeletal structures remained intact despite arguably greater fires.

And if you think this is all "Creationism" and bunk, be my guest. Every theory behind those collapses and the official explanation of the events of that day (all by a commission stacked with Cheney-connected Republicans) is flaccid and reeks strongly of bullshit. Those fires were more smoke than flame and if people were pictured around them in the holes, they obviously weren't that damned hot.

You need to read more on these events and the timeline itself (a good place to start would be The Terror Timeline by Paul Thompson). Even if you toss out all of what you call "fantasy" with the controlled demo theories, what about the several dozens of logical holes in the explanations regarding Flight 93, Flight 77, the Pentagon, WTC 7 (with multiple pictorial evidence) and the wholesale failures of the FAA, NMCC and NORAD, all at the same time, all on that day only?

If you don't think the liquid manure currently holding the White House hostage wouldn't hesitate to conspire in killing powerless citizens for personal and political gain, you're the naive one. Not me.

[mandog]

28. It was my understanding the collapse of the WTC..

Was due to a combination of fire, structural damage and the massive weight of the building above the impact/fire zone. Aren't some of those elements missing from your other examples? And wasn't there a partial collapse in Madrid? It seems to me that the WTC would have remained standing if the combination of variables changes - weaker fires, less structural damage or an impact higher on the building. Your comparison seems weak and superficial - "two big buildings caught fire but only one fell down." Can you amplify why, for example, the Madrid building not having a fully loaded 767 is irrelevant to the issue.

[HughBeaumont]

30. It's irrelevant because the Madrid building burned for 18 HOURS

before collapsing. The plane striking it also had little to do with it:

The aluminum wings and the planes' fuselage would have been almost instantly shredded into pieces the size of an adult's fist, said Tomasz Wierzbicki, director of the impact and crashworthiness laboratory at M.I.T. Engines and other heavy parts continued to the core, but by working out the amount of energy involved, Dr. Wierzbicki and a student, Liang Xue, determined that at most half the inner columns could have been broken or severely mangled.

And you're going to tell me that the South Tower, which was struck SECOND, collapsed basically in it's own footprint within 2 hours despite not even being shaken and motionless from the time it was hit and the catalyst being mostly smoke and not enough flame to even weaken the steel??

http://www.whatreallyhappened.com/wtc1_core.html

[mandog]

32. Half the inner columns being broken is insignificant!

Give me a break! There as for the fires it was calculated (and posted several time in this forum) that the fires had to burn at a rate of 3 to 5 trillion Btu per hour to produce the smoke plume above the towers. You remember that smoke plume don't you - the thick column of smoke that extended for thousands of feet into the air.

But lets ignore how long the Madrid fire burned and address this simple point - the Madrid building was an office building just like the WTC and just like the WTC it was full of combustible material. What you believe is that a fire caused by an electric short circuit started a fire that reached 1000 C in Madrid while a fire started by tens of thousands of gallons of aviation fuel could not reach the same temperature. Do you understand why I have a hard time accepting your argument?

[HughBeaumont]

33. He said AT MOST.

The plane hit near the corner, not dead center, so what that tells me is that not enough of the core was damaged for a free-fall collapse to happen. It still isn't going get me to buy the fact that there was NO VISIBLE CORE, which there should have been at least a few hundred feet of, giving SOME resistance, after the collapse. I can't buy that the inner core provided NO resistance whatsoever.

Both the WTC and Madrid fires were measured to reach about 825 degrees C at most. I don't know where you're getting the 1000C figure.

http://batr.org/view/022805.html

http://bellaciao.org/en/article.php3?id_article=5296

Where's the massive flame that the Madrid fire had for SEVERAL HOURS?

[mandog]

34. Straight from the horse's mouth

Though that risk remained, by yesterday night city officials said it appeared the reinforced concrete core of the building would hold, despite having withstood temperatures in excess of 1,000 degrees centigrade. "Despite all the intense heat, the structure has survived," Javier Ayuso, a spokesman for Madrid's emergencies services, said

http://www.iht.com/getina/files/225478.html

And BTW - read your links carefully. A lot of unsupported statements concerning temperatures with no proof and no evidence.

[petgoat]

44. Madrid Burned for 24 Hours

in a fire that was building on itself. The WTC fires were burning out.
Firemen at the 78th floor of the south tower, which is where all the
blazing aviation fuel should have been betrayed no fear in their radio
transmissions. They matter of factly talked about running hoses and
"knocking down" a couple of fires. They didn't say: "Holy cannoli!
Look at those floor trusses! The building is about to go!"

NIST's steel samples don't show heating above 250 degrees C. 1000
degree temperatures--even if they existed in the fire--do not mean the
steel at the WTC got to 1000 degrees. You can't topple a mailbox with a
propane torch, even though its flame temperature is 3500 degrees F.

[VTMechEngr]

49. Mailbox is a bad example.

The yield strength decreases with heat. But a mailbox is not really supporting much at all. Put a person on it, and yeh, it will topple.

The point is this:

You want to support a 6000 pound ball on a steel stick. You use the standard 60% strength design for buildings and use a steel stick thats rated for 10,000 pounds. A fire at the base of the stick reaches 1100 degrees. The steel now can only hold 5000 pounds. Crunch! That is why building designers worry about fires.

Wood starts burning at 500 degrees and moves to 1100 when it starts to break down. At the charcoal stage, it burns hotter than 1100 degrees. These Temperatures are reached in house fires.

[petgoat]

51. a mailbox is not really supporting much at all

But neither is the WTC. It's supporting itself, as the mailbox is
until--the theory goes--the heat causes it to lose the ability to
support itself.

"A fire at the base of the stick reaches 1100 degrees. The steel now can
only hold 5000 pounds."

This is where you're missing the point. A 1100 degree fire does not
equal 1100 degree steel. Steel is an excellent heat conductor. A 3500
degree F propane torch will not heat a mailbox to 3500 degrees. The
NIST steel samples do not indicate heating above 250 degrees C.

[VTMechEngr]

56. in a 3% sample that even they say is not representitive.

And no offense, but a mailbox is light compared to tens of stories. And a Mailbox probably has a factor of safety of 3 or so.

[petgoat]

58. Steel Conducts Heat Away From the Fire

Even if a mailbox is a poor example the point remains: a 3500 degree F
propane torch flame does not equal a 3500 degree mailbox. The heat is
conducted away by the steel and radiated.

In that same way NIST's postulated 1000 degree C fire does not equal
1000 degree steel. Certainly some of the floor trusses might have
reached that temperature but since they scrapped all the steel there is
no evidence that they did.

Put a 2-foot steel pipe in a campfire and it'll get to 600 degrees C.
Put a 20-foot steel pipe across a campfire and it won't.

[VTMechEngr]

67. And in places where Fire was on both sides of a beam?

As in engulfed? A valid description of the state of the WTC fire.


Put a 20 foot pipe into a fire, and I'll bend it into a U shape in less than an hour.

[pox americana]

70. For ten minutes?

A little smoke damage on the fireproofing, which incidentally was not "blown off" by any planes.

[VTMechEngr]

72. Really, I didn't realize you where in the towers. How lucky you must feel

And no offense, but a house throws off a lot of smoke too. Never see that smokey damage though. It always seems to me that everything got burned.

[janedoe]

74. Not everything was burned.

Her white pants don't look smoke damaged, either. Doesn't look roasted, either. (Note hair waving in the breeze.)

[VTMechEngr]

75. Really weak.

If the fire was in the living room, and she was in the bedroom window, why would she be burned? Why not post a panned out photo, to show the fires above and around her?

Oh yeh, part of that breeze might have been oxygen inflow to the fires. Which she is obviously not close too. What does this prove? Heh, you guys use this as proof of your THEORY?

:rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:v :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:

[janedoe]

77. Bell lap.

Here is the picture you requested. Where are the raging fires that would melt the building?

[VTMechEngr]

78. On the other side of the building.

And in a bigger Pan out. The building has huge columns of smoke in most images. Your picture has little. Why could that be? What are you leaving out?

[janedoe]

79. Perhaps you were confused by the dust cloud

produced by the WTC2 implosion

Sorry, I can't play anymore.

[VTMechEngr]

80. No, the dark colored smoke coming out of the tower. What is that From?

That is not dust my friend. Notice the smoke rolling out of the one side, while very little is rolling out the other. Your picture left that critical info out.

You can't play anymore? Don't bug out on me now, I'm not finished with ya'll yet.

[LARED]

76. You're probably right

all those people that jumped to their deaths just tripped while looking out the windows.

What in the world does that image prove?

[petgoat]

81. The black smoke is from smouldering rugs and office furniture.

Dr. Shyam Sunder said the jet fuel burned out in ten minutes.

The people who jumped did so because of the heat (even 75 degrees C
would be intolerable) and the toxic smoke.

[VTMechEngr]

86. And Dr. Sunder also said:

"... The jet fuel acted much like a matchstick. It was something that spread throughout the building in those affected floors and caused ignition of the fires. But the jet fuel itself burnt in a matter of minutes, within less than ten minutes. So what burned over the next hour, or hour and a half, was really the contents of the buildings, the everyday contents of the buildings...."


Selective quoting of documents. How Republican of you. Come on, Be a Democrat and embrace the Reality and science.

[petgoat]

92. embrace the Reality and science.

I AM embracing the reality. All these years we've been given the
fiction of the blazing inferno. Oh it was there, they say, you just
can't see it, 'cause it's in the core.

Now we find out the steel doesn't support that theory. It's just desks
and file cabinets and rugs, just an ordinary office fire of the kind
that do not bring down steel framed highrises--ever. What was there in
the core to burn? Elevator shafts. Bathrooms. Ah, but those paper
towels and toilet paper really give off heat!!!!

[janedoe]

94. And a "core" elevator was working up to the end...

according to an audio tape of a firefighter.

[VTMechEngr]

96. So? One survived the hit. Good.

Otherwise? Your point? Grasping at straws my so called "structural engineering" friend.

[VTMechEngr]

95. The steel doesn't support it? Where's this from?

Your 250C quote that has been disproven? That quote said those columns were not in the main fire. Hmmm. You a conspiracy insider trying to throw off others? Heh.

Do not bring down steel highrises ever?
WTC1
WTC2
WTC7.

Granted, having planes hit them helped a lot.
And 7 didn't react well to having big chunks ripped out by falling materials.

Your sarcasm was sadly misplaced. The meridian tower that keeps popping up, What kept the fires going? Tissues? Or perhaps the everyday office items. I hope you never see a house fire, lest you camp out on the lawn and claim the fire dept sprayed gasoline on it.

[petgoat]

103. The steel showed "limited exposure if any above 250 degrees C."

Says the NIST report.

ht tp://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf (see p. 6 of the .pdf)

Before 9/11 no steel frame highrise had ever collapsed from fire.

"7 didn't react well to having big chunks ripped out by falling materials."

How come FEMA didn't mention this ten-story hole in the front? They
said they didn't know why it fell.

"meridian tower....What kept the fires going?.... everyday office items."

There were no offices in the core. It was elevator shafts and bathrooms
and HVAC. Nothing to burn.

[VTMechEngr]

106. Already Debunked.

They said it was not a sample of burned out sections.

The core is surrounded on all sides by office space. Impress me by coming up with new moronic arguments that haven't already been debunked 1000 times.

[petgoat]

109. Deschmunked

NIST has no steel showing heating above 250 C. They said so themselves.
They have no sample of the burned out sections.

[VTMechEngr]

119. And if they don't have a sample of burned areas

You know no heating over 250C because:

Let me guess? The aliens told you?

ALREADY DEBUNKED

[petgoat]

121. "aliens told you?" No, NIST says so themselves.

The report says that their steel samples showed "limited exposure if any
above 250 degrees C."

http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

(see p. 6 of the .pdf)

[VTMechEngr]

126. Already explained that one. Like 5 times now.

Already Debunked. Thats all I'm gonna say about it now. Keep using it if you like. Hundreds of DUers are laughing at your expense. :rofl:

[petgoat]

129. "Already Debunked"

Where did you debunk the statement in the NIST report that the steel did
not exceed 250 degrees C?

All you've done five times is assert you debunked it.

[VTMechEngr]

131. I've asserted twice that I debunked it.

I actually debunked at least 3 times. Go look for yourself.

[janedoe]

110. Dude, they couldn't test burned out sections if there weren't any!

You said, "They said it was not a sample of burned out sections."

Well, why do you suppose they decided not to test any burned out samples? Don't you need supporting evidence to prove what happened?

So, let's see your "scientific" methods.

[petgoat]

113. let's see your "scientific" methods.

It's "computer modeling".

It goes like this:

WTC towers: Let's find out how hot a fire we need to buckle the core
columns. Let's draw pretty colored pictures showing floor temperatures
that meet our needs. Voila!

WTC7: Let's see how much structural damage we need to bring down WTC7.
Let's draw a picture that shows the front of the building scooped out.
Voila!

If they could only model the Iraq war all would be peace and harmony!

[VTMechEngr]

117. Ah huh. Previous comment confirmed.

[VTMechEngr]

116. I didn't need methods. I just read the entire paragraph.

You left out some critical info that ruins your argument. The 250C point is bunk. I didn't do the test, the testers themselves said it wasn't representative.

[petgoat]

120. The 250C point is in the NIST report.

It says their steel samples showed "limited exposure if any above 250
degrees C."

http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

(see p. 6 of the .pdf)

[VTMechEngr]

125. in a limited sample: Nuff said'

Be back to kick ass tomorrow. Gotta make dinner.

[petgoat]

130. ""in a limited sample"

Are you postulating that the steel that was recycled was the steel that
showed the heat damage?

That's the only sense I can make of your argument.

When I complain that there's no steel that shows heat damage you say
the steel they have is a limited sample?

[VTMechEngr]

132. Already Debunked.

Reread docs. Reread posts.

[Pepperbelly]

150. furniture and rugs would produce gray smoke ...

black smoke is from a petro product.

[petgoat]

82. Engulfed Steel

You're missing the point. The columns were 1000' high. Certainly there was some inefficiency of heat transfer in the joints, but the heat would be conducted away.

"Put a 20 foot pipe into a fire, and I'll bend it into a U shape in less
than an hour."

A 1" pipe maybe. A 4" pipe no.

[VTMechEngr]

85. Not enough to avoid weakening them.

That is the whole point. I'm driving a dagger into the heart of this pretty fairytale you have about the columns not being affected by the fire. Some heat would be conducted Away, but localized temperature hot spots would remain. Science Fact that even a tin hat can't obliterate.

[Kevin Fenton]

87. Enough to make them give?

I have three questions for you:
(1) Are you saying you think the towers fell as a result of the impact damage + fires? If so, are there any reasons you think they cannot/probably were not destroyed by controlled demolition?
(2) (off the subject of fires) How come the left wing of United 175 devastated the core of the South Tower, but the right wing did much less damage to the east side? Or do you disagree with NIST on this point?
(3) If the north tower was destroyed by the fires (which the NIST claims were worst on the south side) and the south tower was destroyed by the impact damage + fires (mostly on the east side), how come the core of the north tower went first, but the east side of the south tower went first? If the south tower's core was so badly damaged, why doesn't it collapse as a unit? Surely, if the few remaining columns in the SE part of the south tower core give, the load should be transferred to the other core columns, not just the colums on the east side of the tower. But some of the core columns (on the west side) are still there after the east side starts to collapse, how come?

[VTMechEngr]

88. Alrighty, now I have a challenge.

Lemme Fire up my steam roller, The Sir Isaac Newton!

1. Yep I am. Perhaps the fact that controlled demo requires weeks of prep and not one person in the building noticed Any massive holes in walls, charges or Detcord rolling through the place. Oh, but silly me, I guess the government found everybody that knew, and let them die in the building!

2. Probably had something to do with the angle of collision and whether the wing was the leading or lagging one into the collision. I do not have diagrams or video of the collision, so I cannot give a detailed answer yet.

3. Perhaps because the planes hit in different places and took out different sections of columns. You expect them to collapse in the exact same way? Oh wait, You did with controlled demolition! Physics is a bitch isn't it. Lets see, if 40% of the columns were knocked out, then the load increased on the others, but then the fire fixed that, Wouldn't a rational person expect the structure to fail?

Also, the towers didn't collapse as a unit because it wasn't a controlled demo, it was a catastrophic collapse. Random failures would be right in line with the physics. But to answer your question, the east side collapsed, and the building sheared away from the strongest wall (west). The floors collapsed because they were cantilevered from the core and the outer wall columns and when the outer wall broke free, they couldn't stay up.

Take a statics course. Then Take some dynamics and forget this bullshit and realize that the Bush admin did not drop the buildings. The terrorists that the bush admin ignored while declaring war on the evil scourge of Pot smokers that summer brought the building down.

[Kevin Fenton]

91. Eh?

(1) "Perhaps the fact that controlled demo requires weeks of prep and not one person in the building noticed Any massive holes in walls, charges or Detcord rolling through the place. Oh, but silly me, I guess the government found everybody that knew, and let them die in the building!"
I meant was there anything about the collapse that made you think it was not controlled demolition. Sometimes a building falls over and it's obviously not controlled demolition and this can be pointed out with reference to specific features. I thought you might say a feature of the collapse was inconsistent with explosive demolition.
It seems your best objection to explosive demolition is a theoretical one. I make the same objection myself and I doubt the government would have set it all up in the weeks/days before the attack just so they could go to war in Afghanistan and Iraq (there are better ways to get a war there). However, there were opportunities to put in explosives, as the WTC underwent numerous refits, for example after the 1993 bombing. I don't think the argument that it's impossible to put explosives in a building is a good one. If you want an explanation for why the people who put the explosives in aren't talking, it is: the explosives were there to prevent the towers collapsing all over lower Manhattan in a repeat of the 1993 attack. Therefore, the lower-level people who did it, beleive what they were doing was good - most of the people who died in the collapses were already dead/could not have been saved and by taking the towers straight down, they saved lives/property/etc. which may have been hit by the towers if they had collapsed any way other than straight down. You'll remember the towers began bowing just before they fell.

(2) "Probably had something to do with the angle of collision and whether the wing was the leading or lagging one into the collision. I do not have diagrams or video of the collision, so I cannot give a detailed answer yet."
United 175 hit at an angle, the fuselage hit the tower first, followed by the left wing, then the right wing. Surely, the left wing should have been very badly damaged by the initial impact against the outer wall. I can see the engine might have survived this impact and may have done some damage to the core, but severing up to 10 columns there seems way too much.
The account of United 175 hitting the South Tower starts on page 91 of this .pdf file:
http://wtc.nist.gov/pubs/NISTNCSTAR1Draft.pdf

(3) "Perhaps because the planes hit in different places and took out different sections of columns."
The facade sections of columns taken out are broadly similar. Damage to the internal sections is one of the main topics under dispute.

"Lets see, if 40% of the columns were knocked out, then the load increased on the others, but then the fire fixed that,"
What are you talking about? 40% of the columns? 40% of what columns? Not even the NIST is claiming anywhere near this sort of damage - you'd need multiple planes do to that.

"Wouldn't a rational person expect the structure to fail?"
Depends what you mean. If by "fail" you mean partial collapse, then he probably would, but if by "fail" you mean collapse completely, I wouldn't. Also, many experts said they were surprised initially that the towers fell, so obviously they didn't expect it either.

"Also, the towers didn't collapse as a unit because it wasn't a controlled demo,"
If you're trying to imply that it's impossible to set off explosives in half a building without setting them off in the other half, then I think you're wrong.

"the east side collapsed, and the building sheared away from the strongest wall (west). The floors collapsed because they were cantilevered from the core and the outer wall columns and when the outer wall broke free, they couldn't stay up."
If I understand you rightly, you're saying that it was the east side columns that gave first (not the flooring in the eastern part of the tower), but why didn't they buckle or glow red before failing completely? A floor-related collapse would probably not be visible from the outside, but if the east-side columns went, then shouldn't we see them being warped beforehand?

"the Bush admin did not drop the buildings. The terrorists that the bush admin ignored ... brought the building down."
The terrorists certainly flew the planes into the buildings, but did they bring them down?

[VTMechEngr]

97. And a return broadside:

1: If you cut a tree at the base, it falls sideways. Cut the top off, and it falls right to the ground. Simple physics blows that right outta the water.

The rest is well, :tinfoilhat: and I'm here to just play Physics Bitch.
Reload:

2. kinetic energy = .5(mass)(velocity (over 500MPH))^2. Impress me with some math skills and we'll discuss this in further detail. If you have the balls. Kaboom! Reload:

3.
a. If explosives were set lower, the building would probably have fallen sideways. It fell straight down because the hits were so high.

b. The sides of the building were an integral part of the load bearing structure. When comparing the floor plans, several floors are missing 40% of the load bearing surface from the hits. The WTC used a unique design versus other buildings. Thats Important to remember. And is very valid.

c. "but why didn't they buckle or glow red before failing completely?"
Well, for one, you couldn't see them. And two, if you had been paying attention to the entire point of this threat, they don't need to glow red to fail. They don't need to be anywhere near red to fail. Jeez.

Keep sailing the HMS "unsinkable" Titanic at me. I've got plenty of shells on my battleship. :popcorn:

[Kevin Fenton]

173. Take That

(1) I asked, "was there anything about the collapse that made you think it was not controlled demolition?"
And you replied, "Cut a tree at the base, it falls sideways. Cut the top off, and it falls right to the ground?"
I think what's missing here is any sort of link between my question and your reply. But perhaps you were replying to another question from another poster on another thread. Why are you comparing the WTC to a tree - the last time I looked at a tree, it seemed pretty different to a skyscraper - at least its core wasn't made up of joined columns.
More generally, the WTC debate has two groups, the first one claims the WTC was brought down by explosives to facilitate an oil war in Afghanistan and Iraq, the other claims it could have fallen over due to impact damage + fires, so it did fall over for these reasons. Which group is sillier? There's lots of room in between them.

btw, why do you come here to play "Physics Bitch"? Surely, there are establishments which cater to such tastes for which the DU 9/11 forum is but a poor substititue? Do you live in a rural area with no such factilities? Are you presona non grata at all of them in your area?

(2) I asked why the left wing of United 175 did much more damage than the right (or the two on American 11).
You replied "kinetic energy = .5(mass)(velocity (over 500MPH))^2"
Again, the reply seems to be a different question - why would the left wing have had so much more kinetic energy that the right? It's the fuel that made the wings heavy and able to penetrate the outer skin - even the NIST admits that a wing without fuel tanks could not sever one of the WTC's steel facade columns (the wingtips were actually diced by the columns, they did not sever them). And on the initial impact the fuel tanks ruptured, spilling the fuel and making the wings less heavy. So what severed the columns in the south tower core?

(3)(a) "If explosives were set lower, the building would probably have fallen sideways."
You're 'avin a larf. You can't seriously be claiming that if there were explosives, there would have to be only one set, low down.
"It fell straight down because the hits were so high."
In fact, the twin towers did not fall straight down, the east section of the South Tower, for example, fell east.

(b) "When comparing the floor plans, several floors are missing 40% of the load bearing surface from the hits."
Which floors?

(c) Are you saying the east wall columns warped before collapsing or did not warp before collapsing?

[petgoat]

98. Demolition

An expert on controlled demolition, Van Romero, as quoted at
911research, said "It could have been a relatively small amount of
explosives placed in strategic points."

He also mentions another benefit of demolition accruing to the
perpetrators: the secondary attack on the rescue responders is a
common terrorist ploy. Given that the attackers seemed to bend over
backwards to minimize casualities (by striking high up in the towers,
and by striking before 9:00 am) this motivation seems peculiar for an
al Qaeda attack.

But for a Bushcist demolition, the benefit is the great increase in
public regard enjoyed by men in uniform--FDNY and NYPD, which was part
of the emotional environment of authoritarianism under which the
USAPatriot Act was passed. Before 9/11 NYPD had a terrible reputation
after a series of scandals involving shooting unarmed people in the
back and sodomizing a prisoner with a toilet plunger. 9/11 made
criticizing the police unpatriotic.

"controlled demo requires weeks of prep... holes in walls, charges or
Detcord rolling through the place."

Radio control would do away with the need for det cord. Charges could
be mounted in the elevator shafts very quickly, IMHO, riding on the
roof of the elevator cars, and it wouldn't take many people.

Kevin, your argument that the building was brought down by disaster
control people who had nothing to do with the plane attack is, once
again, stellar outside-of-the-box thinking. If they did demolish,
they would then lie about it and cover it up because they don't want
to admit they killed all those people--even if it was the right thing.
Just as the Pentagon wouldn't admit they shot down 93 even if they
did.

[VTMechEngr]

101. We are going to need a new thread soon, but here goes:

I'm the physics guy, couldn't give a damn about your nutso emotional theories, just the physics.

You think charges on elevators would have accomplished that? Few elevators were working that day on the important sections. As for charges, how come nobody noticed any? This kind of thing requires planning. How would they have planned it in a matter of minutes. Without precision placement, the explosives would have to have been huge. And heard.

Radio control would have been way too risky that day, with the radio channels lit up.

And the bomber tried to minimize casualties? WAH?! Flying planes full of people into a building full of people, since the business world gets going by 8am usually, too high up to be rescued by NYFD ladders.

I say again, you are just gone.

[petgoat]

107. "you are just gone"

"charges on elevators....how come nobody noticed any?"

Read my post. I said elevator shafts. I guess nobody noticed 'cause
there weren't any elevator mechanics inspecting the elevator shafts
that day?

"the explosives would have to have been huge. And heard."

Van Romero said a few small charges would do the job. The explosions
were heard. http://www.reopen911.org/Tarpley_ch_6.pdf

"Radio control would have been way too risky that day, with the radio
channels lit up."

Insensitive receivers would not react to false triggers before a
powerful transmitter did the deed.

"the bomber tried to minimize casualties?"

Read my post. Hitting lower down they would have trapped more people
above the fires. Hitting later in the day the buildings would have
been full--58,000 people. The bomber also tried to minimize
casualties at the Pentagon--they hit an unoccupied wing undergoing
renovations. 125 people died in the building, but 100 of them were
civilians.

[VTMechEngr]

112. Yeh, accurate quote isn't it?

Elevator shafts - the ones fire fell down, into the main lobbies? People who are alive, but burned by the falling fuel and debris from elevator shafts finished that one off for you.

One nutcase says. So, Show me others who have real credentials. I won't bother waiting.

Insensitive receivers, powerful transmitter. Plausible, i'll give you that.

Hit any lower and the attacker would have had to do some fancy flying over and around buildings at crazy speeds. That would have upped the chances of mission failure. Remember, 747, not nimble jet fighter.

[petgoat]

118. "One nutcase says....747"

"Hit any lower and the attacker would have had to do some fancy flying
over and around buildings at crazy speeds."

Hey, you never refer to the NIST report, you don't know what's in the
core of the building, and now you seem to think Manhattan is full of
sixty-story buildings. Did you ever even look at a PICTURE of the WTC?

[VTMechEngr]

122. Ah huh. And you actually think the attackers wanted to get that close?

Reality Check. They wanted to hit the WTC, not risk the mission on flying too close to the other buildings.

For the record, I've read up on Minoru Yamasaki's design. The center core was well designed, but outdated to the bigger planes of today. the risky part was the Outer skin being the other load bearing surface. This allows huge open floor spaces that made the WTC a place to work in to companies, but vulnerable to collisions.

[Kevin Fenton]

174. How big was the plane?

What do you mean by, "The center core was well designed, but outdated to the bigger planes of today"?

[VTMechEngr]

182. 747 vs I believe a 727.

[petgoat]

196. 747? No wonder you think the planes brought the towers down.

The towers were designed for strikes by 328,000 pound 707. And the
767's that hit them are only 395,000 pound.

http://911research.wtc7.net/wtc/analysis/design.html

Note also that Jim Hoffman says they were only carrying 10,000 gal of
fuel, not the full 24,000 gal load.

[VTMechEngr]

205. Note I said I think:

Thanks for the info. Still a tangent to my points. Try the main issue at hand.

[Kevin Fenton]

243. What's that got to do with the price of bacon?

The WTC wasn't hit by 747s, but by 767s.

Are you saying that the WTC would probably have withstood a hit by a 727, but that a 767 is a bigger plane (in terms of weight and fuel load) and it's not surprising a 767 knocked a tower over?

[petgoat]

247. price of bacon?

VT clearly doesn't know what's in the core of the building, thinks
Manhattan is full of 65-story buildings, believes despite the testimony
of Van Romero that demolition would be prohibitively complicated, and
believes that NIST's conclusion of collapse by fire despite a complete
absence of evidence is "scientific."

The other guy has been trying to pass off the JOM article by those
Worcester guys as WTC tower steel when it's WTC7 steel.

Then VT tells us that in 137 by "beam" he meant "perimeter column" but
later on by "beam" he meant "core column."

And he thinks a 747 hit the WTC.

I think he's a high school student trying to pass himself off as an engineer.

[mandog]

50. I think you missed this part of the report;

however, these columns represented only 3 percent of the perimeter columns on the floors involved in fire and cannot be considered representative of other columns on these floors.

As for the firemen, NIST (and logic) make it very clear that the fuel had burned off by then and the fires were a standard high rise office building fire. And how large a area is one floor of the WTC? How about 34,000 square feet. And how tiny a fraction of that area did those fire fighter see? And while we are at it, weren't they prevented by damage from entering into the heart of impact zone where the damage trusses would be? They were fighting the bottom of the fire as it spread downward from the point of greatest damage.

[petgoat]

52. entering into the heart of impact zone

The 78th floor was the bottom of the impact zone. I'll suppose that
they couldn't go any higher because the stairways were destroyed or
blocked. I'll also suppose that as trained professionals they
reconnoitered the situation and didn't just start fighting the first
fire they saw.

The evidence is that they saw only a couple of manageable fires. Of
course the evidence we've got it only what the authorities chose to make
public.

[janedoe]

53. elevators

In the audio of the firefighters on the 78th floor, there is talk about sending up supplies (like a stretcher? for the injured people), the next time the elevator was sent up.

This was near the end of the tape, supposedly just as the building came down. So, why were the elevators still working in the core of the building, if it was so hot?

[mandog]

54. So they had no idea how large the fires above them were?

as they couldn't go any higher. There could have been a raging inferno on the 80th floor for all these guys knew.

[StrafingMoose]

31. regarding madrid..

"Look at the Madrid, Philadephia collapses. NO such thing happened with either of them. Both of their skeletal structures remained intact despite arguably greater fires."

There was a partial collapse of the Windsor Tower. I would have like to see how this partial collapse looked it. But true, the whole building didn't collapse like a house of card.

[VTMechEngr]

35. Uh, reality note. The beams wouldn't get tossed out till it collapsed.

You obviously missed that entire point.

[HughBeaumont]

36. I didn't miss ANY point, and stop being condescending.

There's no substantial proof that the beams were solely caused by a "spring tension effect" brought on by a not-that-hot fire supposedly weakening a strong core still substantially intact at the time of collapse; nor does it explain why there was no visible core, which there should have been, collapse notwithstanding. A core that strong should have provided SOME resistance. Perhaps you haven't seen janedoe's footage of the radio tower sinking first prior to the mass falling, indicating the core was blown out first.

The whole thing smacks of controlled demolition no matter how much you refuse to believe it. The odds of three steel-cored buildings completely collapsing in ONE day, within a few hours, in their own footprints, due to fires where no steel buildings fell like houses of cards in their own footprints in HISTORY because of fire are so long it's ridiculous. COME on. This was no miracle, man.

[Name removed]

37. Deleted message

Message removed by moderator. Click here to review the message board rules.

[HughBeaumont]

38. ???????

Right, because the 9/11 Commission's version of what happened is SO credible and believeable.

Boilerplate all you want, it's still bullshit sliced at it's thickest.

:eyes:

[VTMechEngr]

41. OK. What do you believe happened on 9/11?

Just lay out the theory you have. I've never read the 9/11 commission's report. I'm just being an ass to defend physics. The rest of the conspiracy stuff I haven't even touched or read about. So, since I haven't read a total view, lay it out and I'll be polite and not comment on it. I'll call it a learning experience.

[HughBeaumont]

48. Let's toss out ANY controlled demo argument,

since, however more plausible an argument than a steel structure collapsing from smoky hydrocarbon fire without leaving a visible core in it's wake, it may be deemed "extreme" by those who still carry a vague trust that our government wouldn't harm innocent citizens for the purpose of advancing a proto-fascist agenda. Let's toss that out for argument's sake.

When one looks at the complete timeline of the events leading up to, during and after 9/11, you can't help but think that so many of the events seem either too fishy, too dubious or too unexplainably lucky to be merely a coincidence. I believe at the very least that this administration's utter incompetence was the chief reason 9/11 happened, but in light of the timeline and the fact that the Bush administration thwarted an official investigation, underfunded the 9/11 commission, stacked it with Shrub/Big Oil connected Republicans (it took 441 DAYS for an official investigation to begin?) and refused to testify in public leads me to believe that, at worst, this administration knew all along what was going on and possibly had a hand in planning and then covering up what they knew.

Edit - I'll try to get to the events I found to be highly questionable later. Too many to list in the time I have now.

[petgoat]

55. toss out ANY controlled demo

Right. The poor quality of the investigation, the destruction of the
steel, the refusal to release the blueprints all look very suspicious.

For three years the zipper theory of weak perimeter truss clips was
the dogma. Suddenly NIST tells us no, the perimeter truss clips were
so strong that saggy floors buckled the columns.

FEMA could not explain the collapse of WTC7. Then NIST comes in and
says there was a hole in the south face ten stories high. I guess
FEMA just failed to notice that, huh?

It will be interesting to see if the MIT guys challenge NIST in any
way.

We need a truly independent commission--an international commission
composed of engineers whose careers do not depend on alliance with the
powers-that-be in the USA.

But what kind of scientist would agree to study something when the
physical evidence has been destroyed?

[HughBeaumont]

60. Hard questions of 9/11 that deserve to be answered:

* How can the administration claim to have no way of knowing about 9/11 or how it was going to happen when there are more than a few dozen reports of 9/11 "blueprints" (among them intelligence and FAA reports of Al Qaeda agents in pilot training, Bin Laden actively planning attacks inside the US, planes being used as missiles, the 8/6/01 PDB, etc) that the CIA and the FBI either ignored or knew about but marginalized?

* In the weeks and days leading up to 9/11, what was the explanation for highly irregular amounts of puts (that is, a "bet" that a stock will fall in the short term) and other trades on United, AA, the WTC's larger tenants (such as Morgan Stanley, Cantor, Merrill Lynch, etc), gold, oil and T-bonds?

* Why were there reports of children, mosque leaders, and random members of the Arab community telling acquaintances, students and others about the impending attacks? Further, why was Willie Brown told to be cautious in traveling? Why did John Ashcroft cancel flights on that weekend?

* Despite being tracked by the CIA and FBI before 9/11 (the most blatant being Nawaf Alhazmi, Hani Hanjour and Khalid Almihdhar), why were ANY of the hijackers allowed to obtain US Visas, let alone allowed to pass through airport security? Why was there such a wholesale failure of both organizations to place any of these men on terrorist watch lists or aggressive movements towards arrest? Many of these men lived in various places in the US, Alhazmi and Almihdhar openly using real names. Not to mention, why on 9/11 were these men, despite recently being targeted for increased security screenings, having forged identities and outstanding arrest warrants, allowed through airport security with little issue? WTF?

* Why is nobody questioning the ISI for their involvement with Bin Laden and their help with him (and his minions) evading US capture?

* Why is Saudi Arabia being continually touted as an ally despite 15 of the 19 hijackers being of Saudi descent and the publicized and dubious relationship between the Saudi officials and Bin Laden?

* Why was there no effort to evacuate the South Tower despite knowledge that the North Tower had been hit? "The building is secure, please go back to your desks."?????

* Why, despite previously conducting contingency exercises that assumed an attack similar and prior to 9/11, did NORAD more or less perform a complete belly flop in notifying their fighters of the hijacked airplanes?

* Why did ground officials not react more seriously two flight attendant's calls from Flight 11 about the plane being hijacked? Why was NORAD not notified about the Flight 11 hijack until 16 minutes AFTER it was reported by the flight attendants?

* Why was NORAD not informed in a timely fashion when Flight 175 was hijacked?

* Why was there evidence of Flight 93 being shot down rather than crashed? Why did the time stamps indicate that this event happened AFTER it was determined that the passengers fought and overtook the hijackers and two of the passengers on the plane would be able to land it?

* Bush's behavior and demeanor. Continuing of the photo-op despite the worst attack on American soil in history. Joking with the children. Not even a BIT of real concern. Yeah, THAT'S not highly suspect.

* A Cessna was recently within two minutes of restricted DC airspace and was intercepted. So where were the missiles/fighters protecting the Pentagon on 9/11, despite MORE than enough knowledge of the NY attacks?

* The events surrounding the Pentagon attack itself - too numerous and the official account WAY too full of holes to be discussed here. Conflicting reports about just what flew into the West wing - eyewitnesses claim it was no Boeing, nor is there any photographic evidence of remnants of a Boeing crash. WHY did it fly directly into the West Wing, which was under repair, instead of the top? WHY does the official account have us believe that an amateur pilot who sucked at Puddle Jumper U could pull off the (according to many experienced pilots) nearly-impossible and definitely above Hanjour's skill level acrobatics that the supposed 77 did? WHY was the FBI confiscating security cameras from around the Pentagon, a gas station and a hotel within an hour of the crash?

* WTC7 and it's supposed footprint collapse from trash-can fires. Again, can be a thread in itself. Read many of the numerous threads on this forum - they're better at explaining it's fishiness than I am.

* What was with Rummy the Dummy's strange senile Freudian slips about Flight 93 being "shot down", "the missle that hit the Pentagon" and his 8:00 breakfast on 9/11 talking about future "shocking events that will remind the world how important a strong healthy defense department is"???

* How did the media supposedly know EVERYTHING about the hijackers within hours of the crash?

These are just some of the MANY questions of events that seemed too strange to happen all on one day, and the people on this board have been great about educating myself and others about these events (some of which I didn't know about).

Good and credible books to read on this would be The Terror Timeline by Paul Thompson (HIGHLY recommended for the 9/11 curious - EVERYthing he takes is from a mainstream media news source so there's no questioning his bipartisanship), Crossing the Rubicon by Michael C Ruppert and David Ray Griffin's The New Pearl Harbor. Lots of serious hard questions about the logic-defying 9/11 Commission's account of that day.

Really, all we demand is an independent and thourough investigation of what happened that day. The families of 9/11 and the military who are in Iraq and Afghanistan deserve to have these questions answered. Anything less is a disservice to their memories and missions.

[pauldp]

5. Where's your graph explaining

how FEMA could allow all the evidence to be destroyed from a bizarre unexplained collapse that looked similar to controlled demolition?

[VTMechEngr]

73. right here:

http://www.cfree.org/contact/Abduction/Self-Help/Reading.html

[philb]

6. The fires at WTC weren't very hot; and couldn't cause much strength loss

And clearly weren't hot enough to melt the massive steel beams;

yet the President's of 2 construction companies involved in the cleanup of WTC said there was molten metal in the basement of all 3 buildings; WTC1, WTC2, and WTC3.

Now how did those very shortlasting gas fires and some paper fires melt that steel? Never happened before; nor will it ever again.

I think everyone has seen all of the lists about the melting point of steel and the fact the fires at WTC never got anywhere close to the temperature to cause a general collapse of steel beams.


there are many who are familiar with all kinds of equations including fourier transforms and etc.; but they don't shed much light on this discussion. Are you trying to impress someone with such?

[pox americana]

8. And let's not forget the concrete.

The floor diaphragms weren't just a bunch of flimsy trusses loosely connected to the structural cores and exterior walls. No, they were made out of thick concrete slabs tied into corrugated steel floorplates bolted to trusses running in both directions.

So what's the melting point of concrete?

[petgoat]

10. Concrete

I suspect the concrete was special lightweight concrete and was not
structural. But I'm not saying I know. When are they going to release
the blueprints, anyway?

As to the stress-strain diagrams--NIST says steel samples showed
"limited exposure if any above 250 degrees C."

ht tp://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

(see p. 6 of the .pdf)

[pox americana]

21. If it wasn't structural they could have used plywood

or particle board, or cardboard, which is even lighter.

Just sayin... :shrug:

[petgoat]

39. Plywood

I'm really just playing devil's advocate about the dust.

Good point about the weight. I'm assuming the floor was 1) trusses,
2)corrugated steel floor pan and 3) nonstructural concrete. Especially
in a building 110 stories high any springiness to the floor, however
structurally sound, would be unacceptable. Concrete damps this.

A structural floor would have had rebar in it. Why won't they release
the blueprints?

[pox americana]

59. Okay good point.

I don't see any rebar in the pictures but yeah the blueprints will clear up a lot of questions.

What I'm getting at is that it would have been difficult for the burning fuel to heat the floor trusses to ANY temperature simply because as a fluid, it would have spilled and burned on the concrete slabs, not directly on the steel.

[Kevin Fenton]

11. I don't quite get your point

I can see that the steel didn't have to melt and that steel does get soft in a fire. However, the argument is that the specific steel in the WTC did not get soft enough in the specific fire in the WTC. Do you have anything to say about that or are you just mad at the few people here who can't grasp the basics?

[VTMechEngr]

17. I keep getting people who say steel doesn't loose strength in a fire.

I posted this just to show that it does.

[petgoat]

20. Jim Hoffman Says Hydrocarbon Fires Are 825 Degrees C.

This figure is widely repeated, but I haven't been able to source it.

http://911research.wtc7.net/essays/sciam/

Does anyone know the authority for this assertion?

[mandog]

29. But wasn't it a hydrocarbon fire for only a short time?

I read that the aviation fuel's role in the WTC was to ignite all the flammable material in the office spaces and that the fires quickly became regular building fires. I am sure those fires get much hotter that 825 C.

[petgoat]

40. flammable material in the office spaces

The initial dogma from the "experts" was that a raging inferno from the
jet fuel melted the structure. This was later refined to the zipper
theory that said sagging floor trusses unzipped from weak "clips" on the
perimeter columns (while super-strong clips on the core columns tore the
core down as the floors collapsed). Now NIST says the jet fuel attacked
the core columns and the trusses' superstrong clips buckled the
perimeter columns as the floors sagged.

I've never seen anyone assert that paper and particle board and rugs
burned hot enough to distort the steel, but I've only read what I've
read. I'd be interested to see your source.

Why won't they release the blueprints?

[mandog]

47. What burned in Madrid?

It is my impression that from the very beginning it was postulated by NIST that the aviation fuel ignited the contents of the office spaces - I could be wrong but I would like you to show me anything that says NIST thought differently. I think you will find that those "experts" who postulated that it was the fuel alone are simply "internet engineers".

Here is the official NIST version - start on page 22.

http://www.fema.gov/pdf/library/fema403_ch2.pdf

It seems pretty clear to me that the fires were hot enough but I am not an engineer. If you can direct your comments to technical details of the NIST report than maybe we can figure this out.

[Lithos]

176. Madrid lacked the 30-40 stories of building sitting on top of it.

n/t.

[philb]

63. NIST expert says jet fuel likely burned less than 10 minutes.

Dr. Shyam Sunder, Lead Investigator,National Institute of Standards and Technology (NIST): "The jet fuel probably burned out in less than 10 minutes. http://cms.firehouse.com/content/article/article.jsp?sectionId=46&id=25807

[VTMechEngr]

68. Ok, that means what?

I decide i'm burning your house down, so I get a gallon of Gasoline
The Gasoline I tossed into your living room burns for maybe 5 minutes. That doesn't stop you from coming home to a pile of ash and rubble. The secondary fires can burn even hotter.

[pox americana]

69. It means you couldn't even roast a chicken

in that fire, let alone "burn" through concrete slabs to heat the floor trusses to failure (unlike houses, WTC 1 and 2 were not built out of wood, remember?)

[VTMechEngr]

71. Heh, not chicken, Just humans

And I think the plane hitting at 500 MPH helped with the concrete slabs. But the fire, I dunno, maybe the desks, computers, wooden walls, Chairs, Tables, Bookcases, Paper in general, ceiling tiles, cubicles, etc. You don't think that a house just burns down cause its made out of wood do you? What happened the the rest of the stuff in the house? Where did that go? Where is the TV, kitchen table, bed, etc?

[petgoat]

83. Steel-Frame Highrises Do Not Collapse from Fires

Meridian Plaza burned 18 hours, Caracas Tower burned 18 hours.

[VTMechEngr]

90. You really should tell that to all these firms that design buildings.

They would like to know that all those precautions they build in, and BTW, saved those 2 buildings, were never needed. They didn't come down because engineers designed them to keep standing in a fire. The WTC was engineered to withstand them too. And if a plane hadn't ripped huge holes in the sides, they would probably still be there.

[carlvs]

93. Oh really????

I found this tidbit in a detailed report on the One Meridian Plaza fire (www.iklimnet.com/hotelfires/meridienplaza.html)

Firefighting Operations Suspended

All interior firefighting efforts were halted after almost 11 hours of uninterrupted fire in the building. Consultation with a structural engineer and structural damage observed by units operating in the building led to the belief that there was a possibility of a pancake structural collapse of the fire damaged floors. Bearing this risk in mind along with the loss of three personnel and the lack of progress against the fire despite having secured adequate water pressure and flow for interior fire streams, an order was given to evacuate the building at 0700 on February 24. At the time of the evacuation, the fire appeared to be under control on the 22nd though 24th floors. It continued to bum on floors 25 and 26 and was spreading upward. There was a heavy smoke condition throughout most of the upper floors. The evacuation was completed by 0730.

And even if the the building did not collapse as feared, the firemen that fought this fire reported significant structural damage caused by it:

Structural Conditions Observed

Prior to deciding to evacuate the building, firefighters noticed significant structural displacement occurring in the stair enclosures. A command officer indicated that cracks large enough to place a man’s fist through developed at one point. One of the granite exterior wall panels on the east stair enclosure was dislodged by the thermal expansion of the steel framing behind it. After the fire, there was evident significant structural damage to horizontal steel members and floor sections on most of the fire damaged floors. Beams and girders sagged and twisted -- some as much as three feet --under severe fire exposures, and fissures developed in the reinforced concrete floor assemblies in many places. Despite this extraordinary exposure, the columns continued to support their loads without obvious damage

If steel-framed highrises cannot collapse because of fire, then why were the firemen at the scene of the fire told that one was possible? And if fire cannot harm these kinds of structures, then what caused all the damage reported?

[petgoat]

99. Steel Framed Highrises Don't Collapse from Fires

I didn't say they can't collapse. I said they don't collapse. The
firemen were called off the Meridian Plaza because it wasn't worth
risking their lives to put out the fire. Same situation as WTC7.

FDNY had no idea that the towers would collapse.

"If fire cannot harm these kinds of structures, then what caused all the
damage reported?"

That was 18 hours of fire, carl. And even then the building didn't
collapse. The WTC South Tower fires were burning out. Demolition
theorists say that's why it fell first--because once the fires burned
out nobody would believe it collapsed from the fire.

[VTMechEngr]

102. Ding dong - the mind is gone

Burning out you say? how come no one else, other than :tinfoilhat:'s noticed this?

Keep bringing on the ludicrous anti-physics stuff. My Tin foil crushing hammer of Truth is still swinging.

[Lithos]

180. Steel structures are affected by fire damage

Here is a building fire in 62 story LA Bank building which they give repeated credit to the use of fire resisting material on support members (which I suspect was not applied to the WTC due to the age of the construction).

http://www.iklimnet.com/hotelfires/interstatebank.html

This in turn brings up some rather significant differences between the Madrid and the WTC.

1) Madrid was not hit by an airliner. In the case of the WTC, the airliners
- Entered and significantly damaged core structural elements.
- Caused partial floor collapses
- Damaged (physical impact) the main fire proofing material included on all modern steel buildings (because they are susceptible to heat) thus exposing significant portions the steel to direct fire contact.
- Created a short, but extremely intense hydrocarbon fire (which does make a difference) which in turn ignited office components which did burn for over an hour (actually months - they were the cause of the hot spots).

2) Madrid did not have a fairly significant load sitting above the fire damage.

3) Madrid was not anywhere as tall as the NYC buildings.

[VTMechEngr]

23. I can argue that the fires were hot enough to impact the steels strength.

[LARED]

26. An excellent resource for making that argument

http://wtc.nist.gov/pubs/NISTNCSTAR1-5Draft.pdf

[Kevin Fenton]

64. Obviously

The fires impacted the steel's strength. And obviously the impact damage also impacted the structure's ability to carry the load. But to answer the question "Is the collapse of the WTC consistent with the impact damage and fires?" we have to decide whether it's "enough". My understanding is that, if it were not for the impact damage, the steel would have had to lose 80% of its strength, which would have required hot, big and long-lasting fires.

It's hard to estimate how hot the fires were based on just the photos and videos, but my impression is that they were neither, big, hot or long-lasting enough to make the towers collapse.

[petgoat]

65. NIST's Dr. S. Shyam Sunder Says Jet Fuel Burned Off in Ten Minutes

Here it is from the horse's mouth:

http://wtc.nist.gov/media/Public%20Transcript%20021204%...

(see p. 8 of the pdf)

[Kevin Fenton]

66. Jet fuel

The jet fuel must have burned up pretty quick, as you say, although small pockets may have remained after this time. However, the office fires that ensued then must have weakened the steel to some degree, although I find it hard to imagine they weakened the steel enough to make the buildings collapse.

Most people think it was the jet fuel that did it, and it's very important to combat this perception.

[petgoat]

84. people think the jet fuel did it

Right. First off, they assume jet fuel is rocket fuel lite, when it's
really just kerosene.

Second, all the 9/11 events work together to create the impression that the fire-induced collapse is plausible: the Pentagon hellhole, the
apparent disappearance of the wreckage of flight 93, the collapse of
WTC7 after diesel fuel fires.

[VTMechEngr]

89. Create the impression?

Dude, Civil engineers have been taught for decades how steel buildings can come down due to fire. This was known before the 20th century.


You guys are just plain gone.

[petgoat]

100. steel buildings can come down due to fire

Name one steel-framed high-rise that collapsed from fire before 9/11.

[VTMechEngr]

105. The better question that you keep avoiding

Name a building with a tube within tube design that was hit by a 747 without collapsing due to fire?

You can't.

Because a standard design steel frame building, designed to protect the critical columns, had never fully collapsed in a fire proves nothing. None has been hit by a plane, with a tube in tube design (Hint: not the design of the Empire state building) and been left to burn without water to fight it.

Grasping at straws my friend. If you think that repeating the same debunked arguments makes you look smart, may I suggest a better place that uses those tactics: www.freerepublic.com

[janedoe]

104. Dude, you didn't answer his question.

"Name one steel-framed high-rise that collapsed from fire before 9/11."

[VTMechEngr]

108. Maybe because it has nothing to do with the topic.

No building designed like the World trade center towers has been on fire before. Unique design. A detail important to reality based people.

To answer the question: Number of Standard web matrix design buildings that have collapsed due to fire: 0.

Number on fire that can be compared to WTC towers: 0.

Apples to oranges.

Even a 5 year-old could see that.

[petgoat]

111. "Apples to Oranges"

They're your apples and your oranges:


# 89 "Civil engineers have been taught for decades how steel buildings can come down due to fire."

#108 "No building designed like the World trade center towers has been on fire before."

You completely shift your argument, then get insulting when my response
to the first fails to address the second. Your desperation is showing.

[VTMechEngr]

114. My desperation?

:rofl:


Yes, Civil engineers have been taught how fires can bring down buildings.

Lets take a moment to give them a round of applause at the 100% success rate of fire proofing: :applause:

Lets also give the fire fighters who saved all the buildings a round of applause: :applause:

And Yes, no building like the WTC has been on fire before. Unique design. How have I shifted?

[petgoat]

123. " How have I shifted?"

In #89 your argument was that steel buildings collapse in general.
In #108 your argument was that the WTC was unique in collapsing.

Have you finished college yet?

[VTMechEngr]

127. One more before dinner.

Been out for a while. Point you obviously failed to miss. Yes, steel buildings can come down. I.E., ITS PHYSICALLY POSSIBLE. Versus your bullshit its not possible argument.

World trade center had special circumstances versus other example you and others have used. No shift. Just the same complete obviousness as always.

[petgoat]

128. " your bullshit its not possible argument."

I never said the collapse from fire is not possible. I said there's
no evidence for it. I am frankly quite skeptical that burning office
equipment could bring down the core. The open structure of the
WTC was unconventional, but the core was unconventional in being MORE
robust than a conventional highrise. And yet this is the part where
NIST says the steel was heat-damaged.

That the evidence was destroyed over protests is in itself is very
suspicious. Any honest investigation would address the issue of
explosives:

What do the witnesses say?
How many pounds would be required?
Was there an opportunity?
Is the collapse consistent with explosives.

And then it would either show how the idea is wrong or it would admit that it's possible.

Instead they ignore the issue. Did NIST every interview William
Rodriguez? Did the 9/11 Commission? Did they interview Louis
Cacchioli?

And what about the FDNY gag order? Is that any way to treat a hero?

[VTMechEngr]

133. Collapse not consistent with explosives.

It was too random for a controlled demo. Video of the collapse shows that the building did not fall in on itself, but peeled apart like a giant banana.

[petgoat]

134. Collapse Consistent with Explosives says Demolition Expert Romero

VT, one of the things I appreciate about the DU boards is that ad
hominem attacks are absent. In the short time I've been posting here,
you are the only one I've ever encountered who indulges in them, linking
UFO survivor sites, claiming someone's info comes from aliens. Your ad
hominems are showing you have no argument, and certainly are not
demonstrating the expertise you claim.

Van Romero is a demolitions expert, and he said the collapse looked
just like a controlled demolition, that "it could have been a
relatively small amount of explosives placed in strategic points," and
"It would be difficult for something from the plane to trigger an
event like that."

Ten days later he said he thought the fires did the job, but he never
retracted the other statements. It looked like demolition to him, and
only small amounts of explosives would be required.

So with all due respect sir...oh never mind.

[VTMechEngr]

135. Petgoat. I tried the science.

I posted with science to debunk the beams melting argument. Then I challenged the other claims. What I got back was a repeat of concepts I already had attacked. After a point, I just got tired of repeating myself.

The ad hominems are not a sign I don't have an argument. I'm just tired of bothering on people who cannot come up with new concepts for me to discuss. So I'm just having fun jerking you around since you are not trying to have a discussion on the original topic. I'm here to discuss physics and such. I don't care about why the bush admin would do something like this or demolitions theories. My post was to point out the fact that modern building designers worry and design for fires because of a real materials science issue.

Now I see you are by discussing Van Romero. Truthfully, I do not know who he is and cannot continue on him till I have more information. I agree that a few explosives could bring a building like that down in such a wounded state. I've obviously not been sold on the theory, but it is plausible.

I'm sorry I've been hard on you. I had several well, less than pleasant, private messages before I just decided to be a bastard and have my fun.

I'm always up for a discussion on science. Civil like and all.

[petgoat]

136. "I Tried Science"-- You Didn't Like It?

I wasn't complaining that you were being hard on me. I was complaining
because your arguments were dumb.

Here's a start on Van Romero of the New Mexico Institute of Mining and Technology:

http://911research.wtc7.net/disinfo/retractions/romero.html

[VTMechEngr]

138. Thanks for the link. Post 137 highlights my problem with this forum.

[janedoe]

115. With your logic, the color the wall were painted would be an issue.

Let's see... why not count only builings over 1350 feet tall, and disregard all other data?
That logic is downright irresponsible for "pre-business major," let alone someone who claims to have been an engineering student.

[VTMechEngr]

124. "claims to have been an engineering student"

I graduated a while back. You are scary for someone who claims to be a "structural engineer."

And the logic is fine. Seems the engineering world eats it right up.

[petgoat]

42. More Basic Stuff

NIST's steel samples don't show heating above 250 degrees C. The
evidence that would have supported their theories was destroyed by the
authorities. Why won't they release the blueprints?

[VTMechEngr]

43. The burden is to find the beams that were in the crash zone.

That may be the discrepancy.

[petgoat]

45. find the crash zone beams

You can't. The authorities destroyed them over the protests of Fire
Engineering magazine. The firemen rioted, protesting that the "scoop
and dump" cleanup was desecrating the remains of the dead.

[VTMechEngr]

46. And I agree. The clean-up was tacky.

But I think the motive was political and financial based. Money trumps many thing in modern America, including dignity in death.

[petgoat]

57. The clean-up was not "tacky", it was CRIMINAL

It's called "obstruction of justice."

The big point being missed is that few of us are examining the WTC
collapse dispassionately. Bush-haters are dying for a smoking gun and
others consider any suggestion of explosives to be heretical
conspiracy theory.

A rational person could separate the question of "were explosives
used" from the question of "did Bush do it".

It's entirely possible that al Qaeda installed explosives in the WTC
in order to turn a couple of plane crashes into 10,000-year history.

It's entirely possible that the Bush administration is covering up the
fact of explosives not because they did it, but because they are
embarrassed by their failure to prevent it.

To the people who died we owe the truth, and the capture of any
unindicted co-conspirators.

The only way we'll get the truth about the WTC is to have an
independent international commission composed of people whose careers
do not depend on the power structure of the USA.

[Pepperbelly]

61. What's most important to remember ...

when dissecting the cause of a structure failure, it is of paramount importance to be able to carefully remove the rubble, noting the location of each, study those materials and begin to see how the failure occurred. However, in this unique circumstance, two factors precluded that process.

First, the wreckage from all of the collapsed buildings co-mingled. Second, rather than allowing them to piece it apart, they scooped it up for expediency's sake. As a result of this shortcoming in process, the conclusions will be forever challenged and not proven sufficiently to put the questions to rest.

[philb]

62. More important would be to find beams from the areas where all of the expl

explosions were reported. Such as the sub basement, 12th floor, 18th floor, 70th floor, etc. There were witnesses that reported explosions of several floors and were covered with gypsum from the explosions. There were lots of witnesses interviewed who reported such.

Did the 9/11 Commission interview any of the hundreds of witnesses who reported experiencing explosions at the WTC buildings?

[VTMechEngr]

137. One of the Problems with knowing science

Is that those who do not, annoy you so much more. To know a science concept so well, and yet have to keep defending it again and again on a post is just plain frustrating. After a while, I just decided I had had enough.

People post little pictures to make a argument that is not supported by that photo. I have seen limited photos of people and beams flying out to support anti-physics concepts. If I show why its wrong, they repeat that argument, and you soon see why Few engineers post here. The standard CT'er model isn't to debunk physics, its to just piss off the Physics people till they go away. Have I been rude, Yes. I decided I'd be a pain back.

It didn't matter that the woman in the photo was on the wrong side of the building from the main fires, or that steel does shatter when 100,000 tons of material smashes into it from above at high velocities. It kept being brought up to support a theories that neither supported.

On the 250C argument, on page Xli, the report says 3 beams exceeded the 250C temps, but were exposed to less than 600C temps. Modern building design says failure is guessed at 550C. Go to a college today, and 550C is the number used to denote building failure. However, 13% of beams were not of the proper yield strength. That could have been a major problem. The report does state however, and I quote "More than 170 areas were examined on the perimeter column panels; however, these columns represented only 3 percent of the perimeter columns on the floors involved in fire and cannot be considered representative of other columns on these floors.: Page xli.

Page xlii had this gem:
"Note that the perimeter and core columns examined were very limited in number and cannot be considered representative of the majority of the columns exposed to fire in the towers."

In engineer speak, that means they should not be used to defend an argument on a message board.

If you had the science background I had, you would understand the frustration of having to keep explaining what to me are simple physics concepts over and over again. After a few rounds, I just lost respect for my opponents.

[petgoat]

163. That's Not Science!

They examine the steel they've got, and when it doesn't support their
thesis they pretend that the steel they haven't got does.

The scientific fact is that the evidence of the steel does not support
the thesis of collapse due to fires. Why not? According to the
authorities, it's because they destroyed the steel that does.

If that's their argument NIST is no more worthy of our respect than is
the 9/11 Commission or the Warren Commission.

Imagine how that would go over if when they try Saddam they say "I
know that none of his victims will testify to his crimes, but the
victims we are presenting are not representative of all his victims,
many of whom suffered most serious crimes. Unfortunately they are not
here because we killed them. But believe us, they suffered very serious crimes."

That's exactly the argument you are making, and then you try to
pull rank as a scientist to justify it.

NIST goes on to say "Well we killed the witnesses, but here we have
computer animation to show the crimes they suffered at Saddam's
hands."

"the frustration of having to keep explaining "

Try copying your post to a text file, and then you can just cut and
paste it again.

[VTMechEngr]

181. Speculation is not science

[petgoat]

204. Speculation is Not Science--My Point Exactly, and in the absence of

evidence, NIST is engaging in speculation.

Therefore, the only rational option is that the issue remains open, and
we must examine the fact that Giuliani destroyed the evidence, and the
fact that FDNY is under a gag order, and the fact that the blueprints
are not released, and the fact that Bush opposed an investigation from
the start, and the fact that the 9/11 Commission Report was a coverup,
and come to the conclusion that it sure looks as if the Bushcists have
something to hide.

And maybe, as far as WTC goes, it's like Kevin says. They dropped the
building because it was collapsing anyway and it was going to fall on
another building. But the absolute refusal of the investigators to
consider a perfectly reasonable line of inquiry looks pretty strange
too.

[VTMechEngr]

206. Speculation, even in tin foil hat conspiracies, is still not science.

And as such, is not part of this debate.

Thank you for the cut and paste idea, its working well. Speculation is not science. :toast:

[petgoat]

209. "Speculation... is still not science."

I never said it was. You are the one who seems to feel that NIST's
speculative report is scientific proof that the fires felled the towers.

I say the fact that the evidence was destroyed takes it out of the
scientific ballpark entirely. All we can do it speculate. There's no
proof. There's not going to be any proof. Why not? The authorities
destroyed the proof! So all we get is circumstantial evidence.

And the circumstantial evidence is that the authorities are hiding
something. That suggests they're guilty of something.

[VTMechEngr]

210. Speculation is not science

[VTMechEngr]

139. On Van Romero - Seems he denies that the building was demo'd

Puffs Of Dust
CLAIM: As each tower collapsed, clearly visible puffs of dust and debris were ejected from the sides of the buildings. An advertisement in The New York Times for the book Painful Questions: An Analysis Of The September 11th Attack made this claim: "The concrete clouds shooting out of the buildings are not possible from a mere collapse. They do occur from explosions." Numerous conspiracy theorists cite Van Romero, an explosives expert and vice president of the New Mexico Institute of Mining and Technology, who was quoted on 9/11 by the Albuquerque Journal as saying "there were some explosive devices inside the buildings that caused the towers to collapse." The article continues, "Romero said the collapse of the structures resembled those of controlled implosions used to demolish old structures."

FACT: Once each tower began to collapse, the weight of all the floors above the collapsed zone bore down with pulverizing force on the highest intact floor. Unable to absorb the massive energy, that floor would fail, transmitting the forces to the floor below, allowing the collapse to progress downward through the building in a chain reaction. Engineers call the process "pancaking," and it does not require an explosion to begin, according to David Biggs, a structural engineer at Ryan-Biggs Associates and a member of the American Society of Civil Engineers (ASCE) team that worked on the FEMA report.

Like all office buildings, the WTC towers contained a huge volume of air. As they pancaked, all that air--along with the concrete and other debris pulverized by the force of the collapse--was ejected with enormous energy. "When you have a significant portion of a floor collapsing, it's going to shoot air and concrete dust out the window," NIST lead investigator Shyam Sunder tells PM. Those clouds of dust may create the impression of a controlled demolition, Sunder adds, "but it is the floor pancaking that leads to that perception."

Demolition expert Romero regrets that his comments to the Albuquerque Journal became fodder for conspiracy theorists. "I was misquoted in saying that I thought it was explosives that brought down the building," he tells PM. "I only said that that's what it looked like."

Romero, who agrees with the scientific conclusion that fire triggered the collapses, demanded a retraction from the Journal. It was printed Sept. 22, 2001. "I felt like my scientific reputation was on the line." But emperors-clothes.com saw something else: "The paymaster of Romero's research institute is the Pentagon. Directly or indirectly, pressure was brought to bear, forcing Romero to retract his original statement." Romero responds: "Conspiracy theorists came out saying that the government got to me. That is the farthest thing from the truth. This has been an albatross around my neck for three years."

http://www.popularmechanics.com/science/defense/1227842.html?page=4&c=y

Seems he doesn't support that concept after all.

[VTMechEngr]

141. And an important note is the date of the articles.

9/11/01. Hard to make a perfect science explanation (demo) the same day as the attack. I'd think that a few days of study are what did it.

[petgoat]

164. I Already Explained that Van Romero Said the Collapse Looked Like

controlled demolition, and that a small amount of explosives could do
the job, and he didn't think fire did it; then later he decided fire
did it.

But he never retracted the facts that it looked like controlled
demolition and that a small amount of explosives could do it. Those
remain as facts, despite the fact that he changed his mind about fire.

[VTMechEngr]

183. Just ordered a retraction, and said he was mis-quoted.

[petgoat]

199. He didn't retract his opinion that it looked like a demolition & he didn't

retract his opinion that a small amount of explosives could have brought
the towers down.

He only retracted his opinion that the fires could not have brought the
towers down.

[VTMechEngr]

203. He said the fires did bring it down.

And retracted that explosives brought it down. This is not a good example for you to keep using with it tainted like this. You loose credibility by continuously using it.

[petgoat]

207. Baloney

Van Romero is a fine example of what he stood by:

1. It looks just like controlled demolition
2. A small amount of explosives could have done it

The only part he retracted was the statement that the fires couldn't
have done it. Therefore, the proposition that there might have been
explosives stands. Even though we don't expect Van Romero to say so.

[VTMechEngr]

208. Debunked in #139.

And in the Albuquerque Journal, and in Popular Mechanics.

floss, rinse and repeat.

[petgoat]

223. Deschmunked

Romero only retracted his statement that fires could not have brought
down the towers. The other statements: that it looked exactly like a
controlled demolition, and that small amounts of explosives would have
been sufficient, stand.

[VTMechEngr]

224. Speculation is not science. And that argument is now dead.

[VTMechEngr]

140. To those wondering about fire temperatures, and A36 temp specs

Hats off to the DU'er who sent me this link.

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

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

"The jet fuel was the ignition source," Williams tells PM. "It burned for maybe 10 minutes, and were still standing in 10 minutes. It was the rest of the stuff burning afterward that was responsible for the heat transfer that eventually brought them down."

http://www.popularmechanics.com/science/defense/1227842.html?page=4&c=y

Pockets of fire at 1832F is plenty to weaken the beams. Remember, standard design is failure at 550C.

A36 steel specs:
At 300 F - Yield Strength is reduced to 99.50 % of rated yield
At 600 F - Yield Strength is reduced to 97.00 % of rated yield
At 900 F - Yield Strength is reduced to 81.50 % of rated yield
At 1000 F - Yield Strength is reduced to 74.00 % of rated yield
At 1200 F(650C) - Yield Strength is reduced to 39.00 % of rated yield
At 1472.00 F(800C) - Yield Strength is reduced to 18.92 % of rated yield
At 1800 F(982C) - Yield Strength is reduced to 9.00 % of rated yield

[pox americana]

142. hey Mr. Popular Mechanics

There was no pancaking. The NIST report is, um, mistaken.



Get the picture? No buckling, no pancaking, no progressive collapse due to fire.

I'd think about canceling my subscription.

[VTMechEngr]

143. Prove it.

And I don't subscribe. I get Scientific American, Discover, popular science, and Mechanical Engineering.

[pox americana]

144. There is not one shred of evidence to support pancaking.

Not one column out of the 63,140 that would have had to buckle to produce total symmetrical failures.



And if you can't figure out what you're looking at, I can't help you.

[VTMechEngr]

145. And yet I got pictures of steel shattering outward?

How did that happen. And once again, Your picture proves what? A good photo image? This isn't ad hominem, this is valid criticism. Impress me with photos of the collapse showing no pancaking. Because trust me, I'm sure not taking your word on it.

Refer to #137 on my photo policy.

[pox americana]

146. What do you think shattered that steel and blew it all over town?

Or did Popular Mechanics forget to "explain" that?

[VTMechEngr]

147. Pancaking.

But you believe this is bunk. I said prove it. The burden of proof is on you to disprove physics. I should not have to explain High school physics constantly over and over again. And I have decided I will not. I'll explain it once, then its on you guys to disprove a basic physics concept.

So disprove it or shut up.

[pox americana]

149. Okay, just for you:

How much physical evidence of pancaking is there? None.

How much photographic evidence of pancaking is there? None.

What do the available photographs (like this one, from CNN) show?



That the columns which can be seen did not buckle.

So based on the available evidence (photographic only, thanks to Uncle Sam), there is no evidence of buckling and thus no evidence of pancaking or progressive collapse.

Happy now?

[VTMechEngr]

151. Nope, Not Happy.

You used way too small a sample to prove your point. You showed no pictures of the collapse. If their are no photos of pancaking, Whats the Van Romero controversy about.


You use a small photo of columns at ground level from one of the towers, not identified, that may have been on a lower floor that did not pancake, as is thought. You have proved nothing.

If you want to hold your own against a scientist, try using the scientific method. Make a hypothesis, then proceed to find evidence to prove it.

You people do not try. If you want to be taken seriously, put some effort into your thesis.

[pox americana]

152. What are you talking about?

Why are you dragging Romero into it? I showed you the available evidence, and you either can't figure it out or refuse to believe it.

Fine, believe whatever you want. Just don't call it science.

[Name removed]

154. Deleted message

Message removed by moderator. Click here to review the message board rules.

[pox americana]

155. There's nothing scientific about denial

unless you consider psychology a science.

I showed you a photograph of something like 300 intact column sections, none showing any sign of buckling:



And you haven't shown me a single buckled column yet. Go back to your Popular Mechanics.

[VTMechEngr]

156. 300 columns, out of thousands, at the base. You can do better.

To begin, hmm, that rubble around you 300 columns, those look like buckled columns to me. Snapped, twisted and bent. That would be consistent with pancaking. However,

The bottom of the building wasn't going to totally pancake. It was going to build up material and slide over. Your photo shows the side walls at the base. The pancaking happened high up. And the inside seems to be missing in the photo. Intact innards would be more helpful to support your theory. That little photo proves nothing. It neither confirms or disproves pancaking. I admit however, it is a nice photo of a ruined building.

Pancaking would explain these puffs of dust out of the sides and columns snapping and being blown out the sides. Can you explain those?

I don't read Popular Mechanics. I don't need it.



Look closely to the lower left. You can see columns that buckled and were tossed out. They would be the rubble in your photo.



Looks like columns that are not intact to me.

[petgoat]

166. "columns that are not intact"

Frankly, they look shattered, not buckled. None of them are bent.

pox's photo of the base doesn't much impress me either. I'd suppose
that by the time the wreckage hit the ground the floors were just
sheared off. But you are still not providing any evidence of buckling
that is not an artifact of the collapse.

And NIST's assertion that their pictures show buckling before the
collapse are very suspect. How come nobody ever showed such pictures
until now?

[pox americana]

177. Here's the point:

Buckling and "pancaking" are compression failures. Where would this alleged failure compression be the greatest? At the bottom, where the falling mass would have gathered the most momentum.

If there wasn't compression failure at the bottom, there wasn't compression failure period.

[petgoat]

179. I spoke too soon about shear at the bottom

There should be a pile of broken floor plates behind the wall if that's
what happened.

[VTMechEngr]

190. They'd blast out and be in tiny pieces everywhere.

[VTMechEngr]

189. Wow, now that is just a stunning example

Of not know what your talking about. A falling mass in the center would be a compression failure. At a certain point, the innards are going to stack high enough to resist the central fall.

[Name removed]

193. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Name removed]

195. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Name removed]

198. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Name removed]

201. Deleted message

Message removed by moderator. Click here to review the message board rules.

[VTMechEngr]

188. Speculation is not science

If they buckled, they get shattered by the collapse. Duh.

[pox americana]

200. You still haven't figured out what buckling is.

Look it up why don't you.

[VTMechEngr]

202. Know lots more about it than you.

You still don't know what your talking about. Yeah, they buckle. That pretty image was called first modal failure. What do you think happened after the rest of the structure fell down. But I covered this already.

[pox americana]

211. And you think buckling is indicated by "puffs of dust"?

You've been reading too many magazines.

[VTMechEngr]

212. And you a few too many websites.

The puffs are from pancaking however. Not that that seems to matter to you guys.

[pox americana]

170. It there wasn't pancaking at the bottom, there wasn't pancaking period.

But thanks for the laugh.

Incidentally if Popular Mechanics ever runs an article explaining what buckling is with lots of pictures of buckled columns, read it. You'll find it instructive.

p.s. there are no buckled columns in your pictures or mine.

[Name removed]

191. Deleted message

Message removed by moderator. Click here to review the message board rules.

[pox americana]

172. p.s. here's what a buckled steel column looks like

essentially:



Show me one of those okay?

[VTMechEngr]

192. Have a high speed film of the collapse.

You don't actually think they would survive after they buckled like that, do you?

[petgoat]

214. "after they buckled"

Pox's point I believe is that you don't have any pictures of buckled steel, that is, bent steel.

[VTMechEngr]

215. And that would be because they got crushed, or whatever.

Interesting that your explosion theory would do the same thing. Me thinks you doth protest too much.

[petgoat]

217. "your explosion theory would do the same thing."

Do the same thing? You mean not present any examples of bent steel?
You're not making any sense.

[VTMechEngr]

221. Goat, man, 100,000 tons isn't gonna bend steel, its gonna pulverize it.

Why is that so hard to understand?

To clairify:

It would have buckled, then be crushed by the massive chunk of building above. And most would not buckle. Most would be smashed to pieces by a 100,000 ton mass hiting them at freefall. To find a few columns that buckledm is like finding a needle in a haystack.

[petgoat]

225. "100,000 tons isn't gonna bend steel, its gonna pulverize it."

Ah, so now your theory is that the core columns are going to be hammered
into smithereens?

Those fragments of perimeter columns flying laterally into the air--if
they buckled, shouldn't they arrive on the ground bent? In the pictures
they don't look bent.

[VTMechEngr]

230. I have been saying the same thing all day.

I realize you CT'ers must try to distort everything to support your views, but that doesn't change the point. I used buckle in a nonengineering sense with you on how the beams broke apart. This wasn't the u shape, and you know it. You were claiming they never broke apart. I showed several images showing beam fragments flying out.

From now on, I'll use buckle for the U shape failure, and collapse, for the yield failure mode.

If you recall, we were discussing pancaking when I brought out this term in everyday usage.

[pox americana]

222. Exactly. Buckled steel columns show distinct signs of buckling,

I can't find any examples on the web, probably because it's rare for steel columns to fail that way. It's usually concrete columns that buckle.

[VTMechEngr]

226. I've seen examples before.

But this is a tangent. Yield failure(the topic of this thread) is not failure by buckling in the traditional sense. I don't know if any columns buckled in an engineering sense, but I know they yield failed. Its all over the ground in any aftermath image.

A good engineering guess would be some columns buckled. But not enough to see obvious signs on the ground. Assuming of course they actually survived the collapse. I said buckled, but most would in plain speak, be bent in half and snap.

[petgoat]

229. " bent in half and snap"

Got any pictures of columns meeting that spec?

[VTMechEngr]

232. Take your pic. Entire ground is littered with broken columns.

[petgoat]

248. Take your pic.

That's just my point. Show me a pic.

"Entire ground is littered with broken columns"

Yeah right, just like that pretty NIST picture shows the 1000 degree C
floor temperatures.

What was that joke about the Economist? "Assume a can opener!"

[pox americana]

231. No, the tangent is the floor truss failures, which is what your diagrams

are supposed to prove.

The answer is that some trusses failed when the planes crashed, none failed due to heating, and they had absolutely nothing to do with the building collapses, good night.

[VTMechEngr]

233. I have never talked about floor trusses. My diagrams discuss beams

And please don't tell me you went through this entire thread with that wrong in your head.

[pox americana]

234. What beams?

[Name removed]

235. Deleted message

Message removed by moderator. Click here to review the message board rules.

[pox americana]

236. You just got through saying the columns were a tangent.

Anyway, I'm going to bed so good night.

[VTMechEngr]

237. The term buckling was a tangent.

The pancaking was a tangent. Debunk the graph, you cannot, so change the subject you must. We have been engaged in 6 simultaneous conversations ranging all over. You score no points trying to mix them now.

[petgoat]

244. You score no points

I too wondered what were these beams you were talking about when in 137
you said the NIST report on xli "says 3 beams exceeded the 250C temps."
NIST was talking about three perimeter columns, and you called them
beams.

Now you tell us that by beams you meant core columns.

I must bow to your staggeringly superior engineering knowledge sir. You
sure do know how to confuse us poor dumb carpenters. :::::sarcasm

[pox americana]

246. The whole NIST collapse theory depends on buckling

and you're calling it a tangent? Good grief you're completely out of the loop.

[VTMechEngr]

148. For the record, The Pop Mechs article was dead on on A36 steel.

[Lithos]

157. Yep...

Here is a take on the temps the steel did see by study of the microstructure:

http://www.tms.org/pubs/journals/JOM/0112/Biederman/Biederman-0112.html

Also, A36 is more "forgiving" to heat than say A572 (the material which formed the bulk of the structural elements) which depends heavily on a low alloy based fine-grain microstructure for its strength. Another pair of factors which also must be considered are plastic failure (which is a function of time) and columnar buckling (where minor changes in deflection can cause drastic failure, even for minor loads).

Columnar buckling is made significantly worse should some of the side supports as this increases the slenderness ratio of the structure (and thus makes it more unstable). This is what this report indicates WOULD HAVE happened.

http://www.ce.washington.edu/em2003/proceedings/papers/223.pdf

US Steel used to have a book which was the best I'd seen on calculating columnar loading. Depending on the column length, the amount of force necessary to achieve critical failure was actually quite small.

Lithos

[VTMechEngr]

158. 1000C. ouch.

That would have reduced the strength to 5% or so of usual. The Links are great. Are you an engineer or a science guy? Columnar buckling is something I hadn't taken into account, but a first mode or second mode failure would be catastrophic. And yeah, I remember the loads to buckle a column were tiny compared to the shear strengths and yield loads required.

[AZCat]

159. Buckling has been brought up here before...

It didn't take.

I posted some links on the slenderness ratio and the Euler-Johnson curve, but only a few people seemed interested.

[VTMechEngr]

160. Time will tell if my graphs will take.

The initial response was discouraging.

[AZCat]

161. Science is tough...

Just think - you could be a middle-school science teacher. I imagine it's just as difficult to penetrate the minds of pre-teens as it is to make (and keep) a point in an online forum.

[VTMechEngr]

213. Well, one actually got a picture of it.

Shame he hasn't figured out that the beam would be crushed by the collapse.

[Lithos]

162. Engineer

BSME - University of Texas
Also served for two years as a liason for the ISO committee on cranes and the SAE committee for backhoes.

L-

[VTMechEngr]

197. Cool. Welcome to the fun thread.

[petgoat]

216. VT You're Spamming Your Own Thread n/t

[VTMechEngr]

219. No, I'm answering each one of your posts.

[Name removed]

227. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Name removed]

228. Deleted message

Message removed by moderator. Click here to review the message board rules.

[petgoat]

168. 1000 Degrees

That was from WTC7; actually the high-temperature oxidative attack
represented by that paper as well as the unexplained presence of large
amounts of sulfur is regarded by some as evidence of explosives.

[VTMechEngr]

187. Speculation is not science

[petgoat]

167. Your First Ref is From WTC7 Which Burned All Afternoon

So to present that as if it is relevant to a discussion of the towers
is extremely misleading.

Your second ref discusses beam-column connectors. Unless it was based
on a study of the WTC blueprints, I don't see what its relevance is.

[petgoat]

165. "NIST reports that pockets of fire hit 1832°F."

Right. NIST was there with its Radio Shack digital inferno-proof thermometer, but it somehow screwed up and scrapped the steel that would have proved it.

Clearly NIST worked backwards from the results they wanted to prove.

Fire brought down the towers.

We need 1832 F to do the job.

Therefore, we must have had 1832 F.

That's not science.

[Lithos]

175. Not quite

There is quite a bit of evidence such as found in the microstructure of the steel which does show very high temperatures such as around 1000 C were reached.

This is NOT guesswork, but rather is based on comparison to many KNOWN samples. (This is repeatable science which makes it definitive evidence)

L-

[petgoat]

178. "the microstructure of the steel which does show... 1000 c"

That was the JOM article by those guys from Worcestor Polytech, and that
steel was from WTC7. Show me steel from the towers.

NIST says their steel samples showed "limited exposure if any above 250
degrees C."

http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

(see p. 6 of the .pdf)

[VTMechEngr]

186. Debunked in #137. And read 137 while your at it.

[petgoat]

238. 137 says the steel samples do not represent the whole.

Whether they do or not, they're all we have.

http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf

Page xlvi says that out of 170 perimeter locations, they found 2
locations where the temperature exceeded 250 C. That's less than 1% of
the sample. Negligable.

It goes on to say the core columns show little if any exposure above 250 C.

Thus as a practical matter there is no evidence of heat damage.

In science you go with the evidence. The evidence is that the
authorities were covering something up.

[VTMechEngr]

239. 3 actually. And they themselves said it isn't representative.

So its not evidence. If the evidence is not there, you cannot come up with a conclusion to your thesis.

But we have been over this, issue is dead dead dead in 137.

[petgoat]

241. 2 actually, because the third looks like it was heated in the pile after

collapse.

"If the evidence is not there, you cannot come up with a conclusion to your thesis."

Wrong. If the evidence is not there, you cannot come up with a
conclusion to YOUR thesis that fire brought the towers down.

My thesis is that because the evidence was destroyed, no scientific
conclusions are possible and we must examine the circumstantial clues
to determine what is likely the truth. And the circumstantial evidence
is that the authorities are hiding something.

Why won't they release the blueprints?

[Lithos]

250. Okay

So I will take it you have no problem accepting that WTC 7 did suffer sufficient damage from fire to collapse.

Now on to WTC 1 and 2.

The full NIST report you site the executive summary of is quite clear that none of the samples obtained from WTC 1 or 2 were from the heat affected zone. However, the temperatures found from analysis of these few pieces are very consistent with the generated models.

Also for WTC 1 and WTC 2, the main report of the NIST committee you cite repeats on many occasions how the fire did indeed cause damage to the structural integrity from not only weakening the material, but also from the stresses/strains induced by thermal expansion to a building with significant asymmetrical damage including the destruction of major core load bearing members. This is not only bore out by eyewitnesses, but also from the video evidence.

http://wtc.nist.gov/pubs/NISTNCSTAR1Draft.pdf

Note too the repeated, detailed references to the WTC building plans which were available and used by NIST. The fact you are not privy to them is irrelevant.

This load situation was born out by FEMA 403 which states that the damage to the towers forced a redistribution of the load such that the remaining structural members reached unity (100% of maximum load).

The final nail in the coffin of the demolition theory of WTC 1 and 2 is that the video evidence shows an increasing deformation of the building over a significant period of time as the heat effects increaesed the deformation until columnar buckling became inevitable.

Side note: Here is the opinion of a FDNY Deputy Chief of what lead to the collapse. (Also note that his lashing of Tom Ridge on his home page, so he is no friend of the Bush administration).

http://vincentdunn.com/wtc.html

L-

[VTMechEngr]

194. Speculation is not science

[VTMechEngr]

153. A Lesson in how to challenge a scientist

First, Identify the Concept you wish to defend against.

For instance, do not say, Why doesn't a car just fall apart on a road. That is too broad for any science to guy to care with. The controlled demo theory is this way. A science guy has to have a concept to analyze. Conspiracy guys hurt themselves because they just throw out broad concepts and can't defend the details.

You challenge a point to prove your concept. Why don't the wheels come off the axle? You can discuss how the wheel bolts are too small to carry those loads, or too long to avoid snapping. A science guy can then engage the argument, and validate or invalidate the thesis. In this case, I could showing the predicted loads on the wheel bolts are several factors of safety below the strength by cross section and material analysis. On the second half, I could show that the bending moment is too low to cause the shear stress to engage in the formation of cavities where atoms were displaced in the cubic structure of the material, resulting in the creeping crack failure to shear it off.

You guys need to come up with a valid thesis of what happened, then try to explain it and allow it to be peer reviewed. If it can't be peer reviewed without failing, and your only explanation is a conspiracy about that, then its over.

[petgoat]

169. "You guys need to come up with a valid thesis of what happened"

This is the same argument used in the blackbox voting machine controversy.

"Prove that the voting machines are crooked."

I can't. There is no evidence, and the reason there is no evidence
is because the authorities destroyed the evidence.

We in the reality-based community must then look for evidence then in
the inconsistencies and lies in the official explanation.

To continue with the voting machines--the evidence is in the
statistical anomalies, the fact that they remain unexplained, and the
fact that the authorities refuse to release the exit poll raw data and
the voting machine software for analysis.

With the NIST report we look at the fact that they rely on incomplete
computer models, that the physical evidence does not support the
thesis, that the story has changed radically since the Tom Eagar days,
and the physical evidence was deliberately destroyed at the orders of
someone who has Presidential ambitions, Rudy Giuliani.

[pox americana]

171. There's plenty of evidence.

Photographs, video footage, witness testimony, structural analysis, and lots more.

But this is the faith-based physics thread.

[VTMechEngr]

185. Speculation is not science

[VTMechEngr]

184. Speculation is not science

[petgoat]

218. "Speculation is not science" and the NIST report is pure speculation n/t

[VTMechEngr]

220. And your view is speculation that the NIST report is speculation.

Speculation is not science.

[petgoat]

240. Clearly NIST is speculation because they don't have the evidence

to support their theory that the fires brought down the towers.

If they had acknowledged that the destruction of the physical evidence
made their job impossible and is they'd investigated in a half-way
open-minded way the possibility that explosives were used (why couldn't
al Qaeda have planted them? Oh right. Because it would have embarassed
Marvin Bush!) then you could accept the report as a scientific approach
to an unfortunate situation.

As it stands, it's pure speculation.

[VTMechEngr]

242. And you don't have evidence that the fires did not bring them down.

As its obvious we will not be getting anywhere, lets agree to lock this thread and start a new one.

[Name removed]

245. Deleted message

Message removed by moderator. Click here to review the message board rules.

[Lithos]

251. Locking

This thread is repeating itself and now only serving as a catalyst for ad hominem attacks being jointly and severally repeated. It is one thing to disagree at a basal level, it is another to take it to a personal level.

I am going to also ask that a second thread not be started as I rather expect it to repeat in this non-constructive manner.

PM me if you have any questions.

Lithos
Sept 11 Forum Moderator