first time I've seen this picture of white hot motlen metal..

[DemInDistress]

Possible Molten Iron From A Possible Thermite Reaction, On Cedar Street At Ground Zero, Likely From Collapsed WTC 2 , With 90 West Street Building In Background, 9/11/2001








What is that? No way a fire created this material shown above. Then there is this photo :


Did an angular cutter charge neatly slice the steel beam show within the black box? looks like evidence to me

[mirandapriestly]

1. I'm beginning to realize those angular cuts

may have been during the demolition. I had always thought they were from afterwords because there are photos of the guys with torches. but the charges would have had to have been angular or the columns would have remained standing, if the cut was straight across. If they were angular, however, one would slide out from underneath the other. There's no good reason to make angular cuts on the site later that I can think of.

[quickesst]

2. It's the only way...

the towers would collapse into their own footprint. A straight cut would have disrupted the smooth flow of the fall, and it helped contain the damage to a smaller area. If the towers had fallen as the OCT claims, there would have been a huge mass of twisted steel piled as high as a small mountain. I say this knowing that welding of the steel requires standards that basically state that two pieces of metal welded together will be of greater strength than the metal itself if properly done. I learned that in welding school by taking a strips of metal in varying lengths and thicknesses, cutting them in half and welding them back together. When welded properly, the strips of metal would break anywhere but where the actual weld was when placed in a hydraulic stretcher and pulled apart. There are some projects that require flux and or x-ray to determine sufficient quality. I believe the WTC would have been one of those projects. Just an opinion based on practical experience and having at one time been certified to weld metals from 1/8" to unlimited thickness. Thanks.
quickesst

[mirandapriestly]

4. You lost me

on the part about pieces welded together being stronger. I don't understand what
that relates to. I'm a dunce- :dunce:

[Ferry Fey]

5. Like broken bones being stronger where they heal?

Is an equivalent idea that the place where broken bones heal is then stronger than the rest of the unbroken bone?

[quickesst]

6. I knew I had a successful weld...

when I would place a piece of metal, regardless of width into a device we used to test quality. It was a hydraulic stretcher. By taking the piece and securing both ends with a clamp, the stretcher applies pressure on the piece by pulling it apart. If the piece broke at the weld, it was inferior work and would not pass muster. If the piece broke anywhere else along the length, it was a successful weld. Hope this explained it a little better than my first attempt.
Usually it is 7018 used for steel structures which has a tensile strength of 7000 psi. When those buildings are put together, the columns are bolted together, but there is also the added strength of welds. Assuming that the floors below the impact area were never in danger of becoming overheated by the fires on the upper floors, when the collapse started, even if the bolts securing the steel beams could not stand the pressure, the added strength of the welds should have left at least a few large pieces of steel framework intact. And if it's true that the steel was carted away in trucks that happen to have beds basically the same lengths of the steel in the wreckage, then that would indeed be an interesting coincidence. Then again, I may be wrong. There may have not been that strict of requirements for the welding, and they may not have been continuous welds, which would lessen their strength. All I'm saying is, if 7018 welding rods can produce welds that require 2 1/2 tons psi to break, I would think the resistance to collapse would have been more prominent, or rather would have at least shown SOME resistance. But then, that angular cut isn't near any bolt holes or welds either. One more thing I feel I should emphasize. Cutting steel the size of those columns is a hard, hot job. Why would anyone cut twice the steel by going angular, when the easiet path between two points is a straight line? You would not have to apply an angular cut to position the drop of the top piece because there is probably not a professional welder alive who would cut on a vertical column if the top piece being separated were not secured by a crane or some other safe method. Just thought I'd throw that in the demolition vs. cutting torch debate that is sure to ensue. Thanks.
quickesst
Ferry: good analogy

[Ferry Fey]

9. Taking twice as long

One more thing I feel I should emphasize. Cutting steel the size of those columns is a hard, hot job. Why would anyone cut twice the steel by going angular, when the easiet path between two points is a straight line? You would not have to apply an angular cut to position the drop of the top piece because there is probably not a professional welder alive who would cut on a vertical column if the top piece being separated were not secured by a crane or some other safe method.

That's a useful observation. Yes -- with all the cutting needed to be done, why do it in such a way that would require twice as much time and energy?

Is there a chance that the picture we saw of the angled cut could be one taken after a crane had removed the (safely secured) upper piece after a cut, and had moved on?

[mirandapriestly]

13. gotcha. Thanks, good info.

You meant it didn't break off at a weld, right?

[sabbat hunter]

8. ah but they didnt collapse into

but they didnt collapse into their footprints. did you happen to notice the damage to buildings around them. WTC 7, Deustch Bank building, the winter gardens *which lay 6 lanes of traffice plus sidewalks and walkway away*

the winter garden was demolished, and had to be rebuilt.

[mirandapriestly]

3. yup it's white hot

no way no how were those fires hot enough for that to occur. Is that paper on the ground? Why is it white and not burned to a crisp? Remember all that paper floating around in the air?... White. Fires allegedly hot enough to melt steel, but the paper isn't even burned? Ladies n gentlemen , witness The Big Lie.

[m0nkeyneck]

7. explanations for molten metal from this event..

are quite limited; this is a red flag, literally

although it's kind of irrelevant because even if OCT could explain, 99.9% of the population wouldn't be qualified to validate such information.

[mirandapriestly]

14. Especially after listening to Kevin Ryan

the steel was safe up to 2000 and the fires could not have gotten that hot. End of story.

[AZCat]

10. Strange as it might seem...

when an axially loaded metal member fails, it is on a plane 45 degrees from a plane with a normal parallel with the axis of the member.

[Americus]

11. Does seem strange. Got proof? n/t

n/t

[quickesst]

12. Uh...

:wtf: Are you saying that when enough down pressure was applied, the stress caused the column to separate via an almost perfect forty-five degree angular cut? Or are you claiming the steel was mounted on a forty-five degree platform, naturally making the separated column bear the same angle? I see no base plate where the cut exists. Steel columns all have base plates at both ends, and that cut ain't at either one. Please clarify if I have misconstrued your statement. Thanks.
quickesst

[AZCat]

16. An attempt to clarify.

It might sound strange, but because of how (most) metals respond to stresses failure occurs on this "45 degree plane" we are discussing. If you're curious about why, there should be a lot of good primers on something called "Mohr's Circle" on the internet. It's a graphic method that illustrates how normal (as in parallel to the axis) forces cause shear stress along the "45 degree plane". I'd be happy to answer any questions you have. I'm not saying that this necessarily happened in our case, but I would not be surprised if it did. I have a handful of aluminum test samples at home in a drawer that have failed the same way. It happens in both tension and compression (assuming the member in question doesn't buckle first).

[mirandapriestly]

15. You can see the molten metal pooled below it

so I don't think so.

[quickesst]

17. Is this...

what you're referring to? It does seem as though brittle steel will react as you have stated, so is this a case of steel heating up and cooling, is it a ground column that should never have felt the heat from the upper floors, did the action of separation produce enough heat to leave molten steel, were the columns built with flexibility in mind to compensate for movement due to stress? If I could get a good enough look at the surface of the cut, it would help determine the method of separation. It does look to me though, that a tremendous amount of heat was applied at that point. I am a once certified welder, although I'm no longer in the trade, leaving my opinion based only on practical experience, and admittedly nothing on the scale of the WTC. One thing that has crossed my mind is the molten metal pouring from the upper floors. It does glow yellow as in molten steel, and if it were aluminum, hasn't it been established that aluminum will glow silver at the point of melting? If aluminum had reached the point of melting, and was pouring out of the building, would not logic dictate that it would pour silver at that point? Anyway, angular sheer is a possibility it seems. Point taken, and her's the link. Thanks.
quickesst



<http://www.efunda.com/formulae/solid_mechanics/columns/intro.cfm>

[AZCat]

18. I think you are replying to me, but I am not sure.

I apologize if I am mistaken.

I agree that it looks as if heat was applied to the column where it sheared off, although it is hard to tell from this picture. Let me be clear - I am not making any claims about why this column failed, I am just pointing out that it is possible that a column could end up like this through some method other than cutting it (with a torch or thermite, for example). Why it would fail, I don't know. Heating it would certainly decrease the strength of the column, but I don't know where this column was or when it became like this.

[quickesst]

19. Fair enough AZCat

I speak only from my personal experience with welding and using a torch. I personally would not cut the steel at that angle. Twice as much cutting going at an angle like that, and when the piece is cut through, I would assume the top section is secure, I would want the piece lifted straight up from the cut, rather than start a swinging motion, side to side from sliding off an angle. If I were worried about the direction it fell, and if the top were not secure with a crane, etc., the method I would use is to cut through the major part of it, until I could, by pressure, tilt it to a certain angle insuring the piece falls away from the cutter on the final cut. Can't imagine safety guidelines being suspended on a job of this size though. Just my o2. Peace.
quickesst