World Trade Center Construction Flaws Revisited

[STR]

^The NIST report was able to replicate the collapse with sufficient accuracy that we know such a reaction did not contribute substantially to the collapse event.

[GWHH]

http://www.mace.manchester.ac.uk/pro...es/default.htm

[scalziand]

Impressive link.

[marshall]

Very informative information...The Towers essentially pancaked due to the heat and the strain on the steel superstructure. This was due to the intense heat from two fully loaded planes with jet fuel, which the terrorists strategically planned. That was what caused their tragic collapse.

[speedy1979]

Here's another link.

Sorry the original text is in italian but it has more pictures.

http://translate.google.com/translat...e.html&act=url

[THE BIG APPLE]

So is everyone here literally and seriously saying that small fires were the cause of the collapse of those tremendous towers. Heres a quick lesson and brain check.

Steel Temperature Index



Steel melts at 2750°F

Red-Orange flames and fire ball



The temperature of the fire on 9/11 was around 1500°F-1600°F as indicated by the chart and the fireball. Steel can only melt with the use of a blast furnace or a powerfull incendiary (thermite).

The World Trade Center only had small fires burning for 50 minutes. The Windsor Tower in Madrid burned for almost 24 hours and heres the scene on the morning of Feb 13, 2005.

February 12, 2005



February 13, 2005



What you had almost 24 hours later was a standing building, strong enough to support a crane.

[dchan]

^ The fireball in the picture comes from the moment of impact of plane #2. The color of the fireball comes from the instant explosion of jet fuel and minor amounts of other combustibles The chart refers to the color that steel takes on as it's heated. What does the color of one have to do with the other in terms of temperature?

[THE BIG APPLE]

Originally Posted by dchan

^ The fireball in the picture comes from the moment of impact of plane #2. The color of the fireball comes from the instant explosion of jet fuel and minor amounts of other combustibles The chart refers to the color that steel takes on as it's heated. What does the color of one have to do with the other in terms of temperature?

Ok so take a look at this

Red-Orange flames

[dchan]

Originally Posted by THE BIG APPLE

Ok so take a look at this

Red-Orange flames

Again, you're looking at the flames, which takes on the color of the source of combustion (jet fuel, paper, carpet, etc.). Solid steel like the type you would find in a steel building's structure is not a source of combustion, so it doesn't contribute to color of the flames you see (powdered metals, such as thermite, are a far different story). The chart from before refers to the color that the steel takes on, as it does in this picture:



http://www.qualityforgingsteels.com/site/ContactUs/tabid/56/Default.aspx

The colors reference in the chart have nothing to do with the combustion of steel that would lead to flames. As for the Windsor Tower - a quick Google search leads to the wiki on the tower, which leads to this sentence:

It was a very solid building, with a central core of reinforced concrete that resisted the high temperatures of the fire without collapsing.

See for yourself.

http://en.wikipedia.org/wiki/Windsor_Tower_(Madrid)

[THE BIG APPLE]

The steel temperature index indicates a fires color and what temperature it is. As for the Windsor Tower, it had a concrete core. But the Twin Towers had enormous cores them selves that just disappeared on 9/11. It's simple the color of the fire was red-orange which is around 1500-1600 F, and steel melts at 2750 F. Steel never gets hotter than the temperature applied to it, so it didn't melt.

Massive core


"Solid steel like the type you would find in a steel building's structure is not a source of combustion"

So if you're saying that steel does not take on the color of the fire than tell me this, How Did the Buildings Fall?

[dchan]

Originally Posted by THE BIG APPLE

The steel temperature index indicates a fires color and what temperature it is. As for the Windsor Tower, it had a concrete core. But the Twin Towers had enormous cores them selves that just disappeared on 9/11. It's simple the color of the fire was red-orange which is around 1500-1600 F, and steel melts at 2750 F.

1) The fire color has nothing to do with the steel color. Read this for an explanation on the relation between flame color and its sources. Basically different sources create different flame colors:

http://en.wikipedia.org/wiki/Flame

2) The WTC towers had nothing but structure steel as its supports, and soft fireproofing and drywall as its fire resistant materials. It did not have a reinforced concrete core, which resists fires better than steel because it doesn't soften. It doesn't matter how "enormous" the cores are. If it's made only from steel, and a plane with jet fuel crashes into it and combusts, the core is going to have some big problems.

3) The WTC steel did not melt. It merely softened enough that its structural design properties (strength, stiffness, elasticity, etc.) were no longer valid. By that, I mean that the steel became much, much weaker despite not melting. Read "The Fire" section here for a more comprehensive explanation:

http://www.tms.org/pubs/journals/jom...agar-0112.html

P.S. This paper came out in 2001, so don't take it as the ultimate source on the reasons behind the WTC towers collapse. I'm merely using "The Fire" section as a source, since much of it is still valid.

[wong21fr]

^It didn't have to melt, it just had to reach a temperature where it loses it's structural strength and begins to deform. Once it fractures, kinetic energy takes over.

BTW, steel can be deformed outside of a blast furnace or pyrotechnic sources. Ever watch a vehicle catch fire and be left to burn?

[THE BIG APPLE]

Let's look at this from your point of view. You said the towers fell becuase of fire mixed with jet fuel. So then they just happened to fall, and disappear into this air. If it was actually a pancake and structral collapse then wouldn't you see piles upon piles of floors sitting on top of each other. How were four, five, six World Trade Center still standing after the Twin Towers fell on them, and they had the closest proxmity to the Twins. But 7 WTC fell for the same reason the Twins supposedly did. SMALL FIRES.

Small fires


4 WTC



How does fire have the energy to bend steel when it only burned at 1400-1600 F. Take a look.

Huge steel bent from fire! Really?



NY Times



Also another surprising thing about the steel found that day. The steel found after was cut at an angle. Why?

1



2



Demolitionists who are hired to wire buildings from the inside wire the steel columns at an angle like the one seen in the photo above.

[dchan]

Originally Posted by THE BIG APPLE

Let's look at this from your point of view. You said the towers fell becuase of fire mixed with jet fuel. So then they just happened to fall, and disappear into this air. If it was actually a pancake and structral collapse then wouldn't you see piles upon piles of floors sitting on top of each other. How were four, five, six World Trade Center still standing after the Twin Towers fell on them, and they had the closest proxmity to the Twins. But 7 WTC fell for the same reason the Twins supposedly did. SMALL FIRES.

How does fire have the energy to bend steel when it only burned at 1400-1600 F. Take a look.

Also another surprising thing about the steel found that day. The steel found after was cut at an angle. Why?

Demolitionists who are hired to wire buildings from the inside wire the steel columns at an angle like the one seen in the photo above.

1) I didn't say anything about why the towers fell. I merely said that (a) you're confused by the distinction between flame color and heated steel color, (b) the WTC core was made from structural steel only, and not reinforced concrete, and (c) the steel didn't melt. As wong21fr clarified, the steel didn't have to melt - it simply needed enough heat in order to compromise its structural strength.

BTW, did you even read the last source I gave you? It would explain a lot, especially the difference between temperature and heat. Also, the paper is old, so don't take their explanation of why the towers collapsed as my viewpoint - I'm merely using one section of the paper that I feel is mostly valid still.

2) Fire itself doesn't have the "energy to bend steel". Steel bends under a force that exceeds its structural strength properties. In this case, the fire dramatically lowered its structural strength. And then, the different forces within the building bend the various steel columns and beams into whatever shape it turns into. And in the case of a building collapse, you can now add a lot of different dynamic forces that don't occur when a building is just standing.

3) Yes, demolition experts wire it that way because that's the way steel will be naturally cut when it fails in that manner. It's called shear failure. Those columns naturally sheared during the collapse of the towers.

[THE BIG APPLE]

It's simple! The fire was burning yes. Where was it burning, inside both twins, yes. The fire was touching the steel, yes. The fire was red-orange, yes. Red-orange fire/flames are around 1,500 F, yes. Steel melts at 2,750 F, yes. So why the hell is there such thickheadedness. I'm not confused between the difference between steel color and flame color, I know about that very well.



This pic you posted is from inside a blast furnace correct, because that's the only place where steel can take on this color.

Oh BTW someone posted above when a car catches fire, it's burned but still intact, or am I not up to date with STEEL MELTING.

[dchan]

Originally Posted by THE BIG APPLE

It's simple! The fire was burning yes. Where was it burning, inside both twins, yes. The fire was touching the steel, yes. The fire was red-orange, yes. Red-orange fire/flames are around 1,500 F, yes. Steel melts at 2,750 F, yes. So why the hell is there such thickheadedness. I'm not confused between the difference between steel color and flame color, I know about that very well.



This pic you posted is from inside a blast furnace correct, because that's the only place where steel can take on this color.

Oh BTW someone posted above when a car catches fire, it's burned but still intact, or am I not up to date with STEEL MELTING.

Thickheadness? Oy vey.... The point is that the flame takes on the color of the source that combusts. Solid steel does not combust. Other materials do within the building - paper, furniture, carpet, as well as the materials from the plane, including the jet fuel. But solid structural steel does not. Therefore, it adds nothing to the color of the fire. But it will glow to the colors from that chart you posted.

The picture I posted appears to be of the steel rolling process.

And as with the WTC towers (or any other occupied building), a car has many materials within it that can be ignited and combust (seats, carpeting, gasoline, oil). The steel frame is not one of them. Look what usually remains after a car fire has been put out - the steel frame!

[wong21fr]

Originally Posted by THE BIG APPLE

Oh BTW someone posted above when a car catches fire, it's burned but still intact, or am I not up to date with STEEL MELTING.

And the steel frame of the car can often be deformed if the vehicle is left to burn. Which is entirely brought on by the ignition of the flammable components within the vehicle.

[THE BIG APPLE]

Originally Posted by wong21fr

And the steel frame of the car can often be deformed if the vehicle is left to burn. Which is entirely brought on by the ignition of the flammable components within the vehicle.

I have never seen this happen, I've seen cars black as hell after being burned but never melted.

[dchan]

Originally Posted by THE BIG APPLE

I have never seen this happen, I've seen cars black as hell after being burned but never melted.

Deformed doesn't mean melted. As I said before, the melting and softening of steel are two different concepts, and melting occurs at a far higher temperature (the melting point). But steel only needs to reach a far lower temperature than its melting point before its structural strength properties are significantly weakened.

[THE BIG APPLE]

Originally Posted by dchan

Thickheadness? Oy vey.... The point is that the flame takes on the color of the source that combusts. Solid steel does not combust. Other materials do within the building - paper, furniture, carpet, as well as the materials from the plane, including the jet fuel. But solid structural steel does not. Therefore, it adds nothing to the color of the fire. But it will glow to the colors from that chart you posted.

The picture I posted appears to be of the steel rolling process.

And as with the WTC towers (or any other occupied building), a car has many materials within it that can be ignited and combust (seats, carpeting, gasoline, oil). The steel frame is not one of them. Look what usually remains after a car fire has been put out - the steel frame!

The steel rolling process is conducted under very high temperatures to carve the steel. Ok lets get off the concrete building and steel building topic and off the Windsor Tower topic. Lets go back to February 13, 1975 when the North Tower sustained a three alarm fire. I'm sure there were desks and papers on the 10th-14th floors. Why did the building not fall in 1975. I mean it was on the lower floors, so how come the building didn't give way then.