in your professional opinion, can jet fuel melt steel beams?

[cbrunny]

You mean the heroes and workers that were putting their LIVES on the line and THEN had to SUE the government to cover their health expenses etc as they were left on their own afterwords?

well yeah. hospitals gotta make a profit somehow.

 

[The Boston Dangler]

 

[Sonikku]

Wouldn't the steel beams below several floors below the fire still be strong enough to avoid collapsing?

 

[Humpy]

Wouldn't the steel beams below several floors below the fire still be strong enough to avoid collapsing?

You would think, but those buildings were constructed as cheaply as possible using a structural idea that was never used again. They were minimally strong enough to hold themselves up and not much more.

 

[Imp]

Already said, but...

What happens when you warm up plastic but not melt it? Same for a candle?

Does a blacksmith always melt steel to cast it, or does he sometimes warm it up enough to shape it?

 

[Ichinisan]

I am a professional ____.
I profess that ____ is my profession.

In my professional opinion, burning jet fuel will soften steel beams. Under enormous weight, softened beams == not good.

 

[Ichinisan]

Wouldn't the steel beams below several floors below the fire still be strong enough to avoid collapsing?

Not once the chain reaction starts. Everything between them is collapsing and they are being pulled / twisted in directions that gravity alone would not.

 

[Vdubchaos]

well yeah. hospitals gotta make a profit somehow.

Our Government spends MORE money per capita than countries that have social healthcare.

As in, no, hospitals don't HAVE to make money. Making money on heroes is not exactly moral.

 

[amdhunter]

No but thermite placed there by money hungry conservatives looking to pad their military buddies pockets sure will.

 

[preslove]

I don't understand why the kinetic energy of several tons worth of jetliner going a couple hundred mph is ignored by the fucking idiot truthers. The twin towers were built so that the exterior of the buildings provided most of their structural integrity, so the initial impact of the planes seriously weakened the towers and the fires only finished the jobs.

 

[brianmanahan]

Did I suddenly get transported from OT to P&N??? WTF?!

i started this in P&N but i guess it got moved to OT

 

[Ns1]

I don't understand why the kinetic energy of several tons worth of jetliner going a couple hundred mph is ignored by the fucking idiot truthers. The twin towers were built so that the exterior of the buildings provided most of their structural integrity, so the initial impact of the planes seriously weakened the towers and the fires only finished the jobs.

because paint chips.


no, not thermite paint chips, the ones the truthers were nibbling on as kids.

 

[Harrod]

As a network professional I can say that kerosene would have definitely weakened a beam made of network cables bundled together and painted to look like a steal beam.

Seriously, though I would think at the height of the plane crashes, there was probably a good breeze blowing that was stoking the fires at the impact points, while it may have not caused it to melt, the heat + weight of the floors above it would be my guess as to why it did collapse.

 

[Ruptga]

i started this in P&N but i guess it got moved to OT

Achievement unlocked

 

[Captante]

I also know that most American's are easily convinced of just about anything. For example, Mr.Snowden is a hero, yet most Americans will tell you he is quite the opposite.

Perhaps most Americans would, but then I seem to recall a poll which showed that a significant majority of Americans also believed that Saddam/Iraq were responsible for 911.

I doubt the same can be said for the majority of members here.

Anyone with just a bit of brain power knows why the buildings fell: Planes hit them, fire weakened the structure, they collapsed. End of story.

QFT.


Also I strongly suspect that given how much larger, heavier and faster it is then a WWII B-25 bomber, if a 767 liner at full throttle slammed into the Empire State building it would topple on impact.

Quoted from aerospaceweb.org:

"The twin towers of the World Trade Center, by comparison, were struck by Boeing 767 airliners traveling over twice as fast and weighing nearly 15 times as much as a B-25. The energy of impact for the two planes ranged from 2 billion ft-lb (2.6 billion Joules) to 3 billion ft-lb (4.1 billion Joules), some 60 to 100 times greater than that absorbed by the Empire State Building. This estimate is also conservative since it does not account for the energy released by the exploding jet fuel, which greatly exceeded the energy released by the much smaller B-25 fuel supply as well. The greater kinetic energy allowed the 767 aircraft to penetrate much further into the twin towers than the B-25 was able to do at the Empire State Building. Most of the B-25 impact was absorbed by the building's exterior wall leaving very little to damage the interior structure. The 767 impacts, however, not only produced gaping holes in the WTC exterior but also destroyed much of the structural core at the center of each tower."

 

[Jeff7]

A 50mW LED could melt a steel beam, if given an adequately-insulated container.

 

[MongGrel]

Why is this even an issue these days.

It will weaken them enough to cause tons of material built on them to fail.

Like the mega tons of many floors above them.

If you mean 9/11, I saw that coming the morning when I was at work and they were saying it was a cesna or something, when the first one hit. I saw it was a airliner off the bat and there where going to be problems big time when it hit, one of the first things I said was that wasn't a cessna.

I know enough about metallurgy, is part of what I do for a living, that those towers where pretty much in major trouble when airliners hit them.

Snowden is irrelevant to this one to begin withm why even mention it.

 

[Brian Stirling]

This subject is a waste of time as the truthers will NEVER let this nonsense go. I was no fan of the Bush admin but to think they could have planned, organized, and carried out this as a covert action is preposterous. They were never very smart to begin with so making them out to be capable of this is laughable.

The number of people needed to do this is beyond any deniability.

Occam's razor would rule out a Bush/Cheney plan as unlikely in the extreme.

But again, no fact, no reason, no evidence will matter to the truthers.


Brian

 

[Sho'Nuff]

Depending on the type, the max adiabatic burn temperature of jet fuel is about 2,500 K (2,230 °C) (4,040 °F), and its open Air Burn temperature is about 1,030 °C (1,890 °F).

In contrast, many types of steel melt at above 1500C (~2500F)

So no - burning jet fuel in open air will not melt most (perhaps all) steels.

That said, the ultimate strength of steel decreases quite a bit as temperature increases.

See the graph at -

http://www.engineeringtoolbox.com/metal-temperature-strength-d_1353.html

Yellow line shows that above 1100F, the ultimate strength of structural steel is only 40% of what is was at 200F.

For a more detailed analysis of the impact of temperature (and cooling) on various steels, see:

http://www.civil.canterbury.ac.nz/sif/documents/paper19.pdf

Also - it is well understood in materials chemistry that heating (annealing) and cooling (quenching) can have a major impact on the structural makeup of metals and alloys, regardless of whether melting occurs or not. It is quite possible (and even likely) that the heat from burning jet fuel weakened the steel of the trade towers by causing brittle and other weak phases (e.g., martensite) to appear in the structural steel. It is likely the introduction of those phases that rendered the beams unable to support their load and, well, we all know what happened then. But from a strictly academic standpoint, no, burning jet fuel cannot (by itself) "melt" structural steel.

FWIW - long before I was a patent attorney I studied chemistry and materials science, and worked in a metallurgical lab developing materials for the Navy.

 

[jagec]

 

[MongGrel]

Depending on the type, the max adiabatic burn temperature of jet fuel is about 2,500 K (2,230 °C) (4,040 °F), and its open Air Burn temperature is about 1,030 °C (1,890 °F).

In contrast, many types of steel melt at above 1500C (~2500F)

So no - burning jet fuel will not melt most (perhaps all) steels.

That said, the ultimate strength of steel decreases quite a bit as temperature increase

See the graph at -

http://www.engineeringtoolbox.com/metal-temperature-strength-d_1353.html

Yellow line shows that above 1100F, the ultimate strength of structural steel is only 40% of what is was at 200F.

For a more detailed analysis of the impact of temperature (and cooling) on various steels, see:

http://www.civil.canterbury.ac.nz/sif/documents/paper19.pdf

Also - it is well understood in materials chemistry that heating (annealing) and cooling (quenching) can have a major impact on the structural makeup of metals and alloys, regardless of whether melting occurs or not. It is quite possible (and even likely) that the heat from burning jet fuel weakened the steel of the trade towers by causing brittle and other weak phases to appear in the structural steel. It is likely the introduction of those phases that rendered the beams unable to support their load and, well, we all know what happened then. But from a strictly academic standpoint, no, burning jet fuel cannot (by itself) melt structural steel.

I was going to mention annealing, which puts metal into its softer original form once you started, but you covered that.

It is all part of heat treating metal in various forms.

Metal does not have to be melted to be annealed, and will change it dramatically.

It's hard to explain in degrees and the type of metal involved even.

 

[brianmanahan]

Why is this even an issue these days.

i had never really looked into it when it was happening and all the michael moore stuff was going on

thankfully AT is full of brilliant minds who have provided excellent information. i learned more in this thread today than i did on wikipedia!

 

[Artdeco]

Have you seen what passes for steel beams?

I was thinking railroad rail type beams, it's folded sheet steel.

Public TV did a great analysis as well as a ton of other reputable news agencies, only people who refuse to believe are truther fools.

 

[Sho'Nuff]

i had never really looked into it when it was happening and all the michael moore stuff was going on

thankfully AT is full of brilliant minds who have provided excellent information. i learned more in this thread today than i did on wikipedia!

Yeah, approach this rabbit hole with a good bit of caution. There are knuckleheads out there that say that planes never hit the towers or the pentagon, and that 9/11 was a government conspiracy/hoax just like the moon landing. Only unlike the moon landing, lots of people died and even more people witnessed the planes as they crashed. I myself saw the plane that hit the Pentagon and I can say unabashedly that it was one of the scariest and most horrifying things I have ever seen in my life.

 

[MongGrel]

redacted, I've said enough here.