aerialview

WTC main columns.

Those things are big. Jet fuel melted them so I was told. The ones in the pic have been cut to fit on a transport device.

No the jet fuel fire didn't melt them - apparently haven't been paying
attention. Jet fuel ignited combustibles (furnishings, carpets, cubicle
walls and paper, lots of paper. Fires caused floor trusses to sag and
buckle pulling the exterior columns (the waffle shaped pieces in
picture) out of align and softening them. Overstressed columns on
one corner failed causing the building above to fall and crush the
remainder of the building.

reply to post by thedman

If you agree that the pic indeed shows the remains of a central column then where (what level) did these core columns come from. My question is shouldn't there have some of these core columns standing after the collapse.

ps.. Sorry about the thread title. After I hit post I saw the mistake but ATS won't let me edit anything I post or I'm not doing it right. I tried to change the subject/title to "A pic of what the WTC core columns look like" but ATS or something failed and the edit failed.

The core columns were bolted together in sections as were the exterior
columns to form the steel skeleton of the building. The bolts holding
them together are designed to resist vertical loads - as the building
starts to collapse the columns are subject to sideways motion which impart
a shearing force which snaps the bolts causing column to fall.

reply to post by thedman


This is news to me. I have only seen that the core columns were welded and not bolted; welding is important as the specs demand that the weld be as strong as the material itself. This is no negligible point; do you have any proof of this assertion to post?

aerialview,

The pic you posted is of one of the outer rows of core box-columns, and judging by the thickness of the steel it was in the lower 20 floors of one of the towers.

The box columns were set out in two long rows the length of the core, with a grid of smaller H columns between them that held the elevator shafts and mechanical/HVAC conduits, etc. These box-columns were the core of the core and in the base of the building the thickness of the steel that made them up was over 5 inches thick.

They were manufactured in sections about 3 stories tall, welded end-to-end, and their thickness reduced with the height of the towers and the lessening weight they supported.

Well... If that steel column was from 20 floors or down it would have been buried in the rubble but still vertical. How did they get it out so fast? Also maybe someone can refresh my memory as to when they quit looking for survivors.

Peace
dlb

reply to post by aerialview


Since the towers fell from the top down, the lowest levels of debris were from the highest parts of the structures; portions of the lower cores were the last elements to collapse and fell on top of the debris piles. So it actually makes sense that these columns were removed first.

I'm not certain about when the search for survivors ended, but that very day it was already apparent that survival would have been near-miraculous.

reply to post by gottago
I think the cores were built for vertical load. So all the attachments (floors) to these cores got severed away. I still think there should be standing ones. An F5 tornado will destroy a tree to it's central column but the column remains standing. (a healthy tree asumed)

reply to post by aerialview

You wont get any argument from me there; sections of both cores actually remained standing for several seconds after collapse only to collapse in turn. They went down smoldering, too, as if they were made of compacted dust. Google "wtc spire" and you can find videos and photos of them.

They're one of the biggest anomalies about the way the towers collapsed--you look at a photo of the aftermath at ground zero and none of the stumps of the cores are standing. This is just weird, shouldn't happen. They were massive at that level and the cross-bracing was also much stronger at the base, but the hole goes down to the basements.

You have eyewitness accounts from firemen and the janitor Rodriguez that an massive explosion went off in sub-basement of the south tower a few minutes after the plane hit it--and the Naudet video shows that the lobby was wrecked. How'd that occur if the plane hit 80 stories above?

Add those reports to the other reports of intermittent explosions in the towers before they fell, and the seismic shake just before both towers drop, and it's pretty clear that explosives were planted in the basements to take out the cores to get the towers to drop.

reply to post by gottago
Well you took the words right out of my mouth. Maybe I should say we are on the same page about nine eleven. There is so many contradictions.

reply to post by gottago
I don't expect the core columns to be still be standing above the debris pile more than 100 feet. But I still think they would be visible after a straight down collapse.

reply to post by gottago


What if...

The towers fell straight down and it looks like they did to me. And it appears the collapse velocity to be at or near to free fall speed (for mass in our atmosphere) how can the the upper floors be on the bottom of the debris pile.

reply to post by aerialview


The towers were destroyed from the top down, so the uppermost floors came to earth first and were covered by the lower ones. What is most disturbing about the debris field is that basically nothing is connected to anything else, and no recognizable contents or even recognizable body parts were found. Everything was disassociated and blown to shards and bits.

The US Geological Survey even found heavy metals in the dust, and traced them to building contents such as computers, furniture, and pipes and wiring.

Why should a building collapse, even one so big, turn all that to shards and dust?

It took great energy to build the towers. I'm trying to guess at the amount of energy that would be required to bging them down. Should they be equal?