Has Anyone Seen A Realistice Explanation For Free Fall Of The Towers?

[Shrinker]

...mostly about the concrete core because it was the most difficult aspect of the construction.

Evidently, since they seem to have left that part til last!

 

[steve s]

The image of the core wall at base shows those very rigid coils near the center of the concrete core wall.

Elevator cable is not nearly that rigid. Think about it, The cable has to roll up on a reel.

High tensile bar when subected to extreme heat and pressure (always unequally) will coil up as one side gets longer than the other. Think of how a ribbon coils.

Go back and look at that image carefully. That "rebar" you're referring to is curved into a big loop. Not so rigid afterall. It could be cable, conduit, or plumbing pipes. The point is that there's no way you can say with any amount of certainty that it's rebar. And what do ribbons have to do with anything?

Steve S.

 

[Gravy]

I ask you again, Christophera, what's the recipe for invisible concrete?

Christophera's "Invisicrete" Core

The Actual Tower Cores Were Of Steel

​

 

[steve s]

I ask you again, Christophera, what's the recipe for invisible concrete?
​

In one of the Star Trek movies they had "transparent aluminum." Maybe it's something like that. It could be some of that alien technology we got from Roswell.

Steve S.

 

[Apollyon]

That link shows interior box columns and they are not seen very clearly. Also, it should be well known that the NY mayor took the WTC documents and courts will not make him return them. So whatever documentaion exists is being kept secret by authority.

In 1990 I saw the best documentation besides the construction plans. A very intimate video documentary produced by BBC called "The Construction Of the twin Towers". It was 2 hours in length and mostly about the concrete core because it was the most difficult aspect of the construction.

You didn't click through the images, eh?

http://www.greatbuildings.com/cgi-b...enter_Images.html/cid_wtc_mya_WTC_const.4.gbi

Look at Gravy's images as well. You can clearly see there's no concrete core. In fact, Gravy's images and the ones I've linked to are much clearer than the ones you claim as evidence of a concrete core.

Edit. btw, if it was a concrete core, where are the massive forms that would be required to pour such a core? Why is there no picture showing such a significant step in the construction process? What concrete company had the contract to provide the large amount of concrete to form such a core?

 

[Shrinker]

For those that are interested there's a short documentary on the building of the towers here http://www.pbs.org/wgbh/amex/newyork/sfeature/sf_building_pop_01_qt.html

It's a fascinating little thing if you've got the time. It's a little strange seeing a shot of ground zero in the late sixties that looked almost exactly like it I saw it last year.

Anyway, some people won't believe something unless they made it up themselves so I don't expect this will convert anyone...

ETA stuff about the core is in part 2

 

[Christophera]

Concrete Can Be Supported, Not Steel

Thanks. I'm still not understanding, because 3" rebar on 4' centers isn't in layman's terms, but I'll reply anway. You're saying there were no heavy steel beams. I see an abundance of heavy steel in this photo, which appears to be at or near one of the cores.

http://www.truck2bcfd.com/WTC-9.jpg

I count 9 similar columns, clearly hollow, one of them still standing upright. By their orange colour I'd say they were steel. The ladder on one of the columns shows the scale. They look a lot like the columns shown in the construction photo, and seem to match the description of hollow steel columns which apparently appears in the official report. I don't see much concrete.

I'm expecting you will claim this photo supports your claims. Please explain carefully how these steel columns differ from those decribed in the reports. No jargon please, but links to engineering info on the web are okay. Write carefully - if you explain this clearly you might win me round.

The columns with ends that are sheared square support my explanation of how they were sheared.

Post 653 explains why the concrete core is stronger than steel in this application. It actually prevents the steel from deforming so the steel can carry its capacity.

The concrete has all been fractured except for this image of the core wall at base which shows the same columns as your image link which shows interior box columns. The columns were tapered so at the base they were a bit wider than your link which you can see. Yes, they were all tubular. Down low they were hand fabricated, thicker as well, up near the top they were extruded. Those you link to are a bit thicker than the image I have.

The concrete core is visible in a number of images, people just do not know what to look for. For instance the only thing this can be is concrete shear wall next to the spire which is shown again from another angel where box columns are silhouetted.

 

[Apollyon]

That's not a picture of the concret core wall. That's a piece of the concrete floor that has collapsed 90 degrees from its original horizontal position to a vertical one.

 

[Shrinker]

The columns with ends that are sheared square support my explanation of how they were sheared.

Post 653 explains why the concrete core is stronger than steel in this application. It actually prevents the steel from deforming so the steel can carry its capacity.

Understood. Concrete would have made it stronger. But so would many other non-existant things.

The concrete has all been fractured except for this image of the core wall at base which shows the same columns as your image link which shows interior box columns. The columns were tapered so at the base they were a bit wider than your link which you can see. Yes, they were all tubular. Down low they were hand fabricated, thicker as well, up near the top they were extruded. Those you link to are a bit thicker than the image I have.

Okay absence of evidence isn't evidence of absence, right? The concrete could have fallen away. However, more importantly does this detail about the steel columns contradict the official version? You claimed ealier that it does. In what way?

The concrete core is visible in a number of images, people just do not know what to look for. For instance the only thing this can be is concrete shear wall next to the spire which is shown again from another angel where box columns are silhouetted.

I'm prepared to accept for the sake of argument that the spire is the steel core, althoug the photos are far from conclusive. However, there's nothing to say that the more solid areas are concrete. Officially the core contained drywall. How do you know that's not what the photo shows? Also, when these parts of the spire finally fell, did they fall from a height great enough to completely pulverize the concrete? Because if they didn't then there should be some photos of concrete blocks with core colums attached or embedded. You haven't got any by any chance have you? I know, absence of evidence again, but when the absences start to pile up....

 

[Apollyon]

The columns with ends that are sheared square support my explanation of how they were sheared.

Look again. That column wasn't "sheared square." It's an end that's already been torch cut to make the columns a manageable size for moving them to the scrap yard. The striations from the cuts are plainly visible.

Also, look here to see an original of one of your photos. They are stacked for transport to the scrap yard.

http://tinyurl.com/jkxpy

 

[WildCat]

Thanks. I'm still not understanding, because 3" rebar on 4' centers isn't in layman's terms, but I'll reply anway.

Rebar is simply a steel rod used to reinforce concrete. However, having "3 inch rebar on 4 foot centers" is just silly. Rebar isn't 3" thick, it's much smaller in diameter. And it is typically installed on much less than 4' centers, 4' is way too much space to give the reinforced concrete much strength. Here is a picture of rebar being put down before the concrete is poured on a bridge. For a vertical structure it is much the same, only vertical obviously.

There were concrete slabs for the floors of the WTC, but as they didn't carry much of a load there was no need for rebar in them and they did not contain rebar.

Christophera is a complete loon.

 

[kookbreaker]

YEdit. btw, if it was a concrete core, where are the massive forms that would be required to pour such a core? Why is there no picture showing such a significant step in the construction process? What concrete company had the contract to provide the large amount of concrete to form such a core?

Its interesting, but right now in Philadelphia they are building the new Comcast skyscraper at 18th and Arch streets. That sucker is going to be the new tallest building in Philadelphia (beating out the Liberty Places). Even so, it will have a much smaller 'footprint' than either of the WTC towers.

THe point is: In light of 9-11, they are making it 'Airplane proof'. Not 'accidently hit by an airplane'-proof, but 'intentionally rammed by a high speed Jumbo jet'-proof...they hope.

In any case, this means that are putting a lot of concrete around the core. Boatloads of concrete. In fact, they require so much concrete that the concrete suppliers delivery resrouces are stretched thin. A line of cement trucks is waiting at the site almost the whole workday. Meanwhile, Water Department jobs can't get the concrete they need. A sewer replacement job a block away from my place is delayed due to the shortage (with the ground dug up) and a friend of mine who works for the PWD says projects are given concrete by triage as selected by the contractors.

Keep in mind, despite its future size, the Comcast building will be much smaller than the WTC towers. I cannot imagine what kind of drain on concrete suppliers a WTC concrete core would have, especially given the poorer distribution & logistics methods of the early 70's.

 

[Apollyon]

Its interesting, but right now in Philadelphia they are building the new Comcast skyscraper at 18th and Arch streets. That sucker is going to be the new tallest building in Philadelphia (beating out the Liberty Places). Even so, it will have a much smaller 'footprint' than either of the WTC towers.

THe point is: In light of 9-11, they are making it 'Airplane proof'. Not 'accidently hit by an airplane'-proof, but 'intentionally rammed by a high speed Jumbo jet'-proof...they hope.

In any case, this means that are putting a lot of concrete around the core. Boatloads of concrete. In fact, they require so much concrete that the concrete suppliers delivery resrouces are stretched thin. A line of cement trucks is waiting at the site almost the whole workday. Meanwhile, Water Department jobs can't get the concrete they need. A sewer replacement job a block away from my place is delayed due to the shortage (with the ground dug up) and a friend of mine who works for the PWD says projects are given concrete by triage as selected by the contractors.

Keep in mind, despite its future size, the Comcast building will be much smaller than the WTC towers. I cannot imagine what kind of drain on concrete suppliers a WTC concrete core would have, especially given the poorer distribution & logistics methods of the early 70's.

Agreed. It would take an amazing concrete supply to create a core for WTC, not to mention that the construction photos would contain identifiable indications that such a core was being poured.

They would have had to place forms surrounding the columns at each floor in which to pour the concrete. There would be large mixer buckets on cranes. Even if the forms weren't yet in place you'd still see the rebar from the previous floor pour sticking up all over around the perimeter of the core columns so they could be tied in to the rebar for the next floor. None of that is visible in any of the existing photos; photos that would clearly show those indications if concrete were poured as Christophera claims.

 

[Gravy]

Christophera, please send Kookbreaker some Invisicrete. You seem to have quite a surplus.

Christophera, I wish you would click on the links that people post for you. We don't do that for our health, we do it for yours. You've ignored the links I gave you on two forums that refute your claims about the tower cores, and about the north tower spire.

Why ask questions if you're going ot ignore the answers?

Please respond to my post with the video stills above. Do you agree that there's no concrete core there as you describe?

Please try to stop being a child and be a man for once. Buck up, Christophera. A couple of incorrect theories about 9/11 shouldn't shatter your world. Just do a little homework and you can avoid these problems.

You also go on about the north tower spire being part of the core. That's a blatantly ridiculous claim. The spire is a piece of the northwest corner outer wall, as you can see in the photos below (I had also posted these for you elsewhere but you ignored them.)

See the corner of the tower that's indicated in the first photo? See how it lines up with the water tower in the foreground? In photo 2, do you see how the bulk of the building has fallen at the left, and a piece of the outer wall remains at the right? That's your spire, Christophera. Nothing mysterious about it. The third photo shows a closer view.

Oh, and the "rebar" portion of the real core? Your theory makes no sense. 3" rebar on 4' centers makes zero sense, Christophera. Anyway, when you look at a higher-resolution image of that core, you know what's missing? Concrete, Christophera. Are you still claiming that they use the invisible kind?

​

edit: spelling

 

[kevin]

Rebar is simply a steel rod used to reinforce concrete. However, having "3 inch rebar on 4 foot centers" is just silly. Rebar isn't 3" thick, it's much smaller in diameter.

2 1/4" rebar is the biggest in the standards.
http://www.sizes.com/materls/rebar.htm

it looks like for vertical walls rebar spacing doesn't typically exceed 24" on center (don't really have a link for this.)

BTW, the little BBC graphic is wrong about concrete. That image was first used by the BBC on 9/13/2001, 2 days after the collapse. I doubt very much they verified the accuracy. They reused the image in an article on October 4, 2001. However if you actually read the article you'll find it says "But the steel supports in the central cores supporting the towers were protected from fire by plaster that had been sprayed on to them." Plaster is not concrete and fire protection materials of any sort are not structurally supporting.

http://news.bbc.co.uk/1/hi/sci/tech/1579092.stm

Another article, from March 7, 2002, states "The drywall fireproofing surrounding the central columns was highly fire-resistant but not very strong." This matches what I remember from a Nova episode, that the steel central core was protected by fire-resistant drywall (two layers) that was blown off by the explosion exposing the steel.

http://news.bbc.co.uk/1/hi/sci/tech/1858491.stm

 

[Gravy]

2 1/4" rebar is the biggest in the standards.
http://www.sizes.com/materls/rebar.htm

it looks like for vertical walls rebar spacing doesn't typically exceed 24" on center (don't really have a link for this.)

Excellent points, Kevin. I do wonder if we're just talking to the wall here. I'm not convinced that Christophera will even attempt to understand what we're saying.

 

[Hutch]

Just to followup on Kookbreaker and Apollyon, I did some very rough calculations on a concrete core.

I took the 17" that Christophera has mentioned, by a dimension of 90 ft square (360ft total) and a height of 900 ft (ok, probably short, but I'm too lazy to look up the real number, if Christophera is interested he can do the recalculation). In inches this gives me 793,152,000 cubic inches, which translates to 459,000 cubic feet or about 17,000 cubic yards of concrete.

I had trouble locating information, but what I could glean is that the average concrete truck can carry about 9 cubic yards of concrete, so they would need about 2,000 truckloads to do the "Core". Not to mention the infrastructure mentioned by Kook and Apollyon for hauling that mass of concrete up the tower.

Sorta think somebody would have noticed those bills and trucks and that the hundreds if not thousands of construction workers would have been modestly aware of what was going on...

Guess not, in Christophera's world. Chris, where did all that concrete come from?

 

[Christophera]

The picture you reference in post 650 shows has no reinforcing bar visible that can be distinguished at that distance.

If it is not 3" REBAR ON 4' CENTERS, what do you think it is?

 

[Christophera]

Just to followup on Kookbreaker and Apollyon, I did some very rough calculations on a concrete core.

I took the 17" that Christophera has mentioned, by a dimension of 90 ft square (360ft total) and a height of 900 ft (ok, probably short, but I'm too lazy to look up the real number, if Christophera is interested he can do the recalculation). In inches this gives me 793,152,000 cubic inches, which translates to 459,000 cubic feet or about 17,000 cubic yards of concrete.

I had trouble locating information, but what I could glean is that the average concrete truck can carry about 9 cubic yards of concrete, so they would need about 2,000 truckloads to do the "Core". Not to mention the infrastructure mentioned by Kook and Apollyon for hauling that mass of concrete up the tower.

Sorta think somebody would have noticed those bills and trucks and that the hundreds if not thousands of construction workers would have been modestly aware of what was going on...

Guess not, in Christophera's world. Chris, where did all that concrete come from?

The documentary explained that there was a concrete batch plant built at the site to produce all the concrete. I''ve seen a picture of the mixer in WTC constrcution photos recently. Don't remember where. Might have been the Guardian site. It is about a 20 foot diameter drum with a guy using a fire hose to clean it. Your volume figure is off. The floors were concrete too, light weight tho, all but about 10 floors, vermiculite, pumice and flyash w/portland.

 

[Christophera]

2 1/4" rebar is the biggest in the standards.
http://www.sizes.com/materls/rebar.htm

it looks like for vertical walls rebar spacing doesn't typically exceed 24" on center (don't really have a link for this.)

Excellent points, Kevin. I do wonder if we're just talking to the wall here. I'm not convinced that Christophera will even attempt to understand what we're saying.

I didn't see spacings for 3 inch on that site. Very big and it was high tensile steel, very custom concrete. If it is not (note curvature of ALL the pieces) 3" REBAR ON 4' CENTERS what is it?