Why WTC 1 and 2 collapsed on their own taking WTC 7 without explosives

The blaze began before midnight Saturday on the 34th floor of the East Tower in the complex, Briceno said. By Sunday afternoon, it had burned for more 17 hours and spread over 26 floors, reaching the roof. The complex was built in 1976 and is considered a Caracas landmark.
[...]
Earlier in the day, officials expressed fears that the building might collapse.

"There is a problem because the building is made of steel. Because of the high temperatures, the structure could collapse," Interior minister Jesse Chacon told President Hugo Chavez during his weekly radio and television show.

Source

www.whatreallyhappened.com...
news.bbc.co.uk...

Five structural bays rest on four lines of columns in each direction supporting the steel deck. In effect, the concrete structure includes five stacked steel buildings, each supported by a macroslab. During the fire, two steel decks partially collapsed; other than that, there was no collapse inside the building. However, deflection in some steel beams was severe.

Source

That's what you get from a 17-hour, 26-floor fire.

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WTC7 suffered less severe fires for a shorter amount of time.



So why did WTC7 fall?

[edit on 22-3-2006 by bsbray11]

I think you should submit your facts for the 1 Million Dollar Prize that no Engineer or Physics expert has been able to do.

1 Million Dollars... GO FOR IT!

Originally posted by Darkmind

Originally posted by NinjaCodeMonkey
Towers rock back and forth all the time, they are supposed to. Explosives brought those towers down, that is the only logical explanation.

And having a plane slam into each tower, causing vast amounts of damage is no longer an acceptable cause for their collapse? Is not a logical cause for their collapse?

Damn it...

If you official story supporters don't stop saying this...well, keep saying it, it just makes your position more laughable.

Why? Because the OFFICIAL STORY says that the planes DID NOT cause the collapse!!! So, take your logic issues up with them, homey. In the meantime, keep this point of view; it just makes the official story that much less credible...

The Parque Central complex was not a steel skyscraper. It was a 56 story reinforced concrete and steel skyscraper. It is nothing like the WTC towers.

"Caracas Tower" Parque Central complex towers

The reinforced concrete structure consists of perimeter columns connected by post-tensioned concrete “macroslabs” that are each 10 feet (3 meters) deep and above the second–floor mezzanine, the 14th, 26th, 38th, and 49th floors. There’s no central core.

Just look at the pictures, the Caracas tower has columns fairly evenly spaced, the opposite of what the designers of the twin towers implemented. The Caracas building does not even have a central core.

The building is more similar to WTC 7. The main difference being that the Caracas building did not have to withstand the collapse of two much larger skyscrapers practically on top of it.

There is this picture showing signifigant damage to a corner of WTC 7.



But according to your standards of evidence, you better show us pictures of the insides of all three buildings looking like this . . .



to prove demolition.


BTW does anyone have a theory of exactly where the explosives were planted?

How about the exact sequence of explosives required to bring down the towers?

Is there any positive evidence for demolition?

Negative evidence against the official story, is not positive evidence of controlled demolition. It reminds me of creationists trying to tear down evolution as if that would somehow prove a biblical young earth.

For details of where the differing charges were placed and what their action entailed please see the thread entitled "How they rigged the towers" You will note that this theory acknowledges all of the known evidence, in sharp contrast to the OCT which cannot account for various phenomenon.

Gordon.

Originally posted by LeftBehind
The building is more similar to WTC 7. The main difference being that the Caracas building did not have to withstand the collapse of two much larger skyscrapers practically on top of it.

I think that's the point that bsbray is trying to say....that the caracas building was like WTC7 and burnt for 17 hours and didn't collapse but WTC7 burnt for 7 and did.

There is this picture showing signifigant damage to a corner of WTC 7.

That photo is misleading at best. You can't see what the percentage of the building is damaged there. It looks to be about three rows of columns on the one side and who knows how many rows of columns on the other. What percentage of the buildings columns does this contain? I want to see a better photo of the damage to WTC7 before I can call that damage major structurally.

But according to your standards of evidence, you better show us pictures of the insides of all three buildings looking like this . . .

to prove demolition.

Again...if you believe that plane damage and fire alone brought down the buildings, then why do we have to jump to "the entire building would have to be wired"? Why couldn't it just be some thermite in the basement to sever the core columns and one explosion to knock the cap and start the fall? If you believe plane damage and fire, then why is that scenario soooooo hard for you guys to believe?

BTW does anyone have a theory of exactly where the explosives were planted?
How about the exact sequence of explosives required to bring down the towers?

See above.

Is there any positive evidence for demolition?

Sulfide residue....see NIST.

Negative evidence against the official story, is not positive evidence of controlled demolition.

True....but negative evidence against the official story still puts a negative light on the official story......demolitions or not.

Sulfide residue will apear from the heating of the steel, and no, that building described is not built in the same way as the WTC.

There is no evidence of demolition, yet there is a large amount of data, from 4 different investigations( FEMA,NIST, 9/11 commision, prviate Silverstien commsion) which suggest the same conclusion. The towers were weakened by the initial strike, and the ensuing fires led to the collapse of the WTC.

These commisions contained experts and scholars who were as or more qualified than the scholars for 9/11 truth, so they are fully qualified to come to a scientific answer and provide specualtion and fact into the true cause of the collapse.

Originally posted by esdad71
These commisions contained experts and scholars who were as or more qualified than the scholars for 9/11 truth, so they are fully qualified to come to a scientific answer and provide specualtion and fact into the true cause of the collapse.

You have to remember that these scholars are working backwards to come up with how the buildings collapsed. They start with the assumption that plane damage and fire were the only factors, so of course they are going to come up with these theories. The scholars for 9/11 truth don't start with the assumption of anything and let the science guide them not them guiding the science like the official scholars.

Originally posted by esdad71
Sulfide residue will apear from the heating of the steel,

Sorry, forgot to include this quote with last post.

Since A36 steel is composed of iron and carbon.....how would heating the steel make sulfide residue appear? Don't try and use Howard's theory of the gypsum being the culprit. Gypsum board (drywall) is used in the construction industry for FIRE BARRIERS. Meaning that a fire (even as "hot" as the WTC fires) will not make the gypsum react with the steel.

And what about the molten steel found in the bottom of the debris field weeks after the collapse? There are photos of a crane lifting a glowing hunk of metal out of the rubble. The color of the piece is yellow to orange indicating heating well above the capacity of hydrocarbons. And the aerial thermal images again indicate hot spots in the debris field well above what could be reaonably explained by jet fuel, office materials and the like. For the metal to have been heated that high the heat source would have had to have been immense and localized.

There are clearly questions without answers.

Bsbray, at first you post:

Originally posted by bsbray11
The Caracas Tower was a steel skyscraper that suffered a 17-hour long, 26-floor fire without major damage. But again, you'll call foul somewhere, I'm sure.

Then you post:

Originally posted by bsbray11

Five structural bays rest on four lines of columns in each direction supporting the steel deck. In effect, the concrete structure includes five stacked steel buildings, each supported by a macroslab. During the fire, two steel decks partially collapsed; other than that, there was no collapse inside the building. However, deflection in some steel beams was severe.

But you failed to include the information right above the part you quoted:

The reinforced concrete structure consists of perimeter columns connected by post-tensioned concrete “macroslabs” that are each 10 feet (3 meters) deep and above the second–floor mezzanine, the 14th, 26th, 38th, and 49th floors. There’s no central core.
Individual floors between the macroslabs have a steel-deck floor supported by steel beams, all protected underneath with spray-on Cafco Blaze Shield DC/F mineral glass fiber wool with cement fireproofing.

So which is it? Is it a steel building or a concrete building or a combination of the two?

Incidentally here is a picture of the collapsed portion of the Caracas tower. Note the standard box grid of beams and columns. This is not the same sort of structure in the WTC buildings.

This image was taken by retreating fire personnel as they left the partially collapsed 35th floor.

source

So what many people here are arguing is this:

But it still does not explain away the initial attempt in prior years to plant explosives/thermite in the basements of the towers. Nor does it account for the fact that thermite takes time to burn.. would one hour be enough time to burn through major structural supports in the basement? What is the burn rate of thermite btw?

The WTC from its initial design was made to collapse upon the collision with a sufficiently sized plane with a sufficient amount of fuel?

could not the designers of the day not forseen larger planes in the future? They did brag that the towers were designed to withstand a crash from a smaller plane than a 757 did they not? Was not larger planes talked about or envisioned in that time in the 60s, so why did the designers not scale up the project then in structural terms? There is no good excuse for this that I can see. Also, there was a massive rush to build these buildings, which still has not been fully explained too.

also, does not the WORLD TRADE CENTER itself have globalist NWO connotations to it?

Well folks the answer is this: this was a planned occultic event from day one.

Has anybody counted how many days from completition of the tower untils its destruction for example?

It doesn't matter any more how the towers fell, because I know who did it, what I don't know is why? What was gained from this operation in the sense of the occult?

Originally posted by Esdad71
Sulfide residue will apear from the heating of the steel,

This is totally false.

Gordon.

Edit
OK. This is untrue because a sulfide residue will not appear from the heating of steel. There is no history of this as a phenomenon in any of the many materials science and mechanical engineering sources that I have studied, not does the poster provide a link to back up this wild assertion.
It would appear to be a statement made without reference to any known science or reasoning and seems simply to be added to try to hold together a tale which is coming apart at the seams like a cheap suit.
In short the statement that Sulfide residue will appear from the heating of steel is totally false.
Mod Note: One Line Post – Please Review This Link.

EDIT: Fixed BBCode

[edit on 23-3-2006 by AgentSmith]

[edit on 23-3-2006 by gordonross]

Originally posted by Griff
Don't try and use Howard's theory of the gypsum being the culprit. Gypsum board (drywall) is used in the construction industry for FIRE BARRIERS. Meaning that a fire (even as "hot" as the WTC fires) will not make the gypsum react with the steel.

If you are going to make the claim that because gypsum drywall is used for fire barriers, then it is some how inert or impervious to chemical changes due to prolonged heating, please explain what happens to gypsum after prolonged heating above 185 degrees C????








For those of you who don’t want to wait to see how Griff sidesteps this question:


Gypsum:

Gypsum is a very soft mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4•2H2O.

Heating gypsum to between 100°C and 150°C (302°F) partially dehydrates the mineral by driving off exactly 75% of the water contained in its chemical structure. The temperature and time needed depend on ambient partial pressure of H2O. Temperatures as high as 170°C are used in industrial calcination, but at these temperatures the anhydrite begins to be formed. The reaction for the partial dehydration is:

CaSO4•2H2O + heat → CaSO4•½H2O + 1½H2O (steam)

The partially dehydrated mineral is called calcium sulfate hemihydrate or calcined gypsum (commonly known as plaster of Paris) (CaSO4•½H2O).

The dehydration (specifically known as calcination) begins at approximately 80°C (176°F), although in dry air, some dehydration will take place already at 50°C. The heat energy delivered to the gypsum at this time (the heat of hydration) tends to go into driving off water (as water vapor) rather than increasing the temperature of the mineral, which rises slowly until the water is gone, then increases more rapidly.

The endothermic property of this reaction is exploited by drywall to confer fire resistance on residential and other structures. In a fire the structure behind a sheet of drywall will remain relatively cool as water is lost from the gypsum, thus preventing (or substantially retarding) damage to the framing (through combustion of wood members or loss of strength of steel at high temperatures) and consequent structural collapse.

The anhydrous form, called anhydrous calcium sulfate (sometimes anhydrite), is produced by further heating to above approximately 180°C (356°F) and has the chemical formula CaSO4. Anhydrite reacts slowly with water to return to the dihydrated state.

So, can calcium sulfate cause sulfidation of steel?

According to this abstract from technical journal it can.

Abstract: It was found through erosion-corrosion and corrosion experiments that calcium sulfate can either protect a base metal from erosion-corrosion by forming calcium-compound-iron-oxide layers on the surface or increase its sulfidation; calcium sulfate's action is determined by its content in erodent particles, temperature, particle velocity, and duration.

source

Sulfate compounds are well known to be corrosive to steel at high temperatures.

Originally posted by HowardRoark

Sulfate compounds are well known to be corrosive to steel at high temperatures.

So is sulfidated thermite. Just out of curiosity, at what temperatures does this happen? I've looked but can't find anything.

Once again, I would like to present just a few of many eye witness accounts to the extent of the damage to WTC 7.

Deputy Chief Nick Visconti
Division 14 - 34 years

I don’t know how long this was going on, but I remember standing there looking over at building 7 and realizing that a big chunk of the lower floors had been taken out on the Vesey Street side. I looked up at the building and I saw smoke in it, but I really didn’t see any fire at that time.

Deputy Chief Peter Hayden
Division 1 - 33 years

By now, this is going on into the afternoon, and we were concerned about additional collapse, not only of the Marriott, because there was a good portion of the Marriott still standing, but also we were pretty sure that 7 World Trade Center would collapse. Early on, we saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that and we were pretty sure she was going to collapse. You actually could see there was a visible bulge, it ran up about three floors. It came down about 5 o’clock in the afternoon, but by about 2 o’clock in the afternoon we realized this thing was going to collapse.

Firehouse: Was there heavy fire in there right away?
Hayden: No, not right away, and that’s probably why it stood for so long because it took a while for that fire to develop. It was a heavy body of fire in there and then we didn’t make any attempt to fight it.

Captain Chris Boyle
Engine 94 - 18 years

So we go there and on the north and east side of 7 it didn’t look like there was any damage at all, but then you looked on the south side of 7 there had to be a hole 20 stories tall in the building, with fire on several floors. Debris was falling down on the building and it didn’t look good.

But they had a hoseline operating. Like I said, it was hitting the sidewalk across the street, but eventually they pulled back too. Then we received an order from Fellini, we’re going to make a move on 7. That was the first time really my stomach tightened up because the building didn’t look good. I was figuring probably the standpipe systems were shot. There was no hydrant pressure. I wasn’t really keen on the idea. Then this other officer I’m standing next to said, that building doesn’t look straight. So I’m standing there. I’m looking at the building. It didn’t look right, but, well, we’ll go in, we’ll see.

So we gathered up rollups and most of us had masks at that time. We headed toward 7. And just around we were about a hundred yards away and Butch Brandies came running up. He said forget it, nobody’s going into 7, there’s creaking, there are noises coming out of there, so we just stopped.

www.firehouse.com...

Originally posted by HowardRoark
So which is it? Is it a steel building or a concrete building or a combination of the two?

From what I read it seems like it was a combo of the two, and I read this after my initial post so apologies for not being clear on the first one. The site I was citing was describing steel "decks" set up with concrete in between them, sort of like several steel buildings stacked and divided up by concrete, as that one source put it.

I didn't see any diagrams or anything so I don't know the exact set up from that kind of info alone, but they don't sound like the skyscraper in Madrid, for example, which was just concrete with rebar with little thin, round beams for outer support columns, and I've read nothing about steel "decks" there.

Incidentally here is a picture of the collapsed portion of the Caracas tower. Note the standard box grid of beams and columns. This is not the same sort of structure in the WTC buildings.

Nope. It looks pretty shabby, too, compared to the WTC. Not because of the fire, but because of those lonely-looking columns.

external image

And the WTC suffer weaker fires, and yet globally collapse while losing no momentum?

Originally posted by HowardRoark
Once again, I would like to present just a few of many eye witness accounts to the extent of the damage to WTC 7.

Got any pictures? I mean we have plenty of eyewitnesses describing explosions but these don't seem to count in some people's opinions.

Also, if the building had holes in one side wouldn't that affect the direction of collapse?


[edit on 24-3-2006 by uknumpty]

Something is WRONG about the OFFICIAL STORY that should obvious to anyone.

If there were nothing wrong why does the US government not close that case one and for all.

It seems strange to me that Larry Silverstein in an interview says that they pulled it because it was damaged when demolition teams say that it takes time planning something like this.

This indicates that it was done before the planes hit WTC.

Gypsum is a very soft mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4•2H2O.

Heating gypsum to between 100°C and 150°C (302°F) partially dehydrates the mineral by driving off exactly 75% of the water contained in its chemical structure. The temperature and time needed depend on ambient partial pressure of H2O. Temperatures as high as 170°C are used in industrial calcination, but at these temperatures the anhydrite begins to be formed. The reaction for the partial dehydration is:

CaSO4•2H2O + heat → CaSO4•½H2O + 1½H2O (steam)

The partially dehydrated mineral is called calcium sulfate hemihydrate or calcined gypsum (commonly known as plaster of Paris) (CaSO4•½H2O).

The dehydration (specifically known as calcination) begins at approximately 80°C (176°F), although in dry air, some dehydration will take place already at 50°C. The heat energy delivered to the gypsum at this time (the heat of hydration) tends to go into driving off water (as water vapor) rather than increasing the temperature of the mineral, which rises slowly until the water is gone, then increases more rapidly.

The endothermic property of this reaction is exploited by drywall to confer fire resistance on residential and other structures. In a fire the structure behind a sheet of drywall will remain relatively cool as water is lost from the gypsum, thus preventing (or substantially retarding) damage to the framing (through combustion of wood members or loss of strength of steel at high temperatures) and consequent structural collapse.

The anhydrous form, called anhydrous calcium sulfate (sometimes anhydrite), is produced by further heating to above approximately 180°C (356°F) and has the chemical formula CaSO4. Anhydrite reacts slowly with water to return to the dihydrated state.

For anyone not sure of the chemical formulae, I will put this into layman's terms.

If you heat it, it will dry out.
The chemical composition will differ only in that there is less water, because it is being dried out.
The chemical structure will not be altered in any way other than there being less water.
This will not make it any more likely to react with steel than if not dried out.
So the answer to the question, will this make a reaction with steel more likely, is an emphatic no, absent other conditions.

The bond between calcium and sulphur is stronger than the bond between steel and sulphur.
If it was possible to disassociate the sulphur and calcium then hot corrosion could take place between sulphur and steel but sustained temperatures above 970 C are required for this phenomenon to take place.

If I put flour, sugar, marge and fruit in my cupboard, the next time I open it I will not find a fruit crumble. In the same vein, if I take those ingredients, put them in a bag, set it alight and throw it out the window I will still not have a fruit crumble. Similarly in chemistry it is necessary to have all of the constituents and all of the correct conditions in place before the reaction can take place.

Gordon.