On the structure of the WTC

[rumpel]

I remembered seeing pictures of the construction of the WTC in a Native American Journal after the "attack". For the life of me, I do not remember which pubication it was. There were comments from those that built the towers. We do no longer receive the publication. The feature story and the cover picture was of the Mohawks Iron Steel workers who built the WTC.
To this day, these people are called "Skywalkers".

http://www.sites.si.edu/images/exhibits/Booming%20Out/index.htm

this is the South Tower:
http://www.sites.si.edu/images/exhibits/Booming%20Out/pages/booming1_jpg.htm

As there seem to be some issues on the structure, I thought it may be interesting to track down these people or at least pictures of the construction, so by googling I did find some
info.

http://sonicmemorial.org/public/stories.html
(The Mohawk Skywalkers are under "stories" here) some pictures

audio:
http://www.npr.org/templates/story/story.php?storyId=1145947

General architectural info on the WTC & 7

http://www.greatgridlock.net/NYC/nyc3b.html#73

Interesting also is this site's link to a personal website of how the building behaved at and after impact as told by employees of Garban Computer Systems,
a subsidiary of Garban Securities, a government bond brokerage. This company seem to have been occupying offices in both towers. Floor 26 in one and Floor 55 in the other.

Shirley: "The elevator doors were about to close. I let another
woman go ahead of me. I told the passengers I'd take the next one.
Right after that I heard a loud whoosh, like a strong wind.
I didn't know what was going on. I started running, but before
I got through the revolving door, all the glass fell on me.
I got all cut up. Look here, where my head was slashed.
I'll have these bandages on my wrist for awhile."

Danielle: "One guy I work with, Pat, you remember him?
He was downstairs for a cigarette & waiting for an elevator.
When the doors opened, flames shot out of them & killed the
guy in front of him & the guy beside him almost immediately.
Pat got burns on about 30% of his body, or something like that.
It's amazing he's alive. I guess he's in pretty good spirits
because I heard that he joked with Steve that he's now uglier
than he is. I don't know when or if he'll come back to work."

From the perspective of my office:

Many: "When the plane first hit, we heard this loud 'wwwwwwffffffffump.'
Almost immediately after that, the building swayed one way, then
rocked back & swayed in the other direction, then shook briefly
but violently as the building righted itself."

"It felt like the building was going to just tip over on its side.
It seemed to be just at the edge of falling before swaying back
the other way & doing the same thing in the opposite direction.
Then it straightened up & shook. I nearly fell over twice."

"All the stuff on my desk slid over to the other side."

"My chair rolled towards the other cubicle."

Snip

"There was some smoke in the stairwell, but not that much.
When we got to the last couple of floors though, there were
a couple of inches of water on the ground, probably from the
building's sprinkler systems. Some women were actually worried
about their shoes!"

"None of us in the stairwell heard the 2nd plane hit.
Nobody had any idea. Those stairwells must be super-insulated
or something for us not to hear that. Really, everyone was
pretty calm & orderly going down the stairs."

"All the elevator doors were black & burnt out & mangled at all
kinds of odd angles. There were a couple of inches of water on
the floor. They were hoarding us away from the central courtyard
towards West Street."

snip

"We were down on the 44th floor when the plane hit our building.
The windows all broke & chairs & equipment, anything near the
windows, got sucked out of the building."

One of the first people I asked my boss about was Rich.
I was extremely worried about Rich because he is the
kind of guy who would have told everyone,
"Don't worry; I'll stay behind & make sure the system is up & running."
Thankfully & amazingly, especially given that they knew I was out on
jury duty (we cover each other), Rich was working from home that day:
"I had no idea about anything until the connection went dead.
The system was up & running right up until the building collapsed."


http://www.geocities.com/ejerlin/

[Kevin Fenton]

1. Very interesting, thanks

"Danielle: "One guy I work with, Pat, you remember him?
He was downstairs for a cigarette & waiting for an elevator.
When the doors opened, flames shot out of them & killed the
guy in front of him & the guy beside him almost immediately."
This appears to be a local elevator going up to floor 26 of the North Tower (assuming Pat was returning to his office); it was not connected to the impact zone, so why is fire coming out of it?

"All the elevator doors were black & burnt out & mangled at all
kinds of odd angles. There were a couple of inches of water on
the floor. They were hoarding us away from the central courtyard
towards West Street."
Lots of witnesses report the same thing - elevator door blowout, although some were still functioning initially.

[philb]

3. Which tower were the elevators in?? story is inconsistent with firemen

statements regarding WTC1. There were little if any doors blown out initially.

What would cause local elevators that were functioning initially to stop working? They were nowhere near the plane impact or fire.

In WTC1 a big explosion happened on floors 22,23, or 24 that destroyed some local elevators. What caused this explosion and when did it occur?

http://www.flcv.com/firemen.html

[rumpel]

5. I also thought that was confusing. Strange also that the computer systems

guy said that the system was up until collapse. Which implies power and internet connection (phone or cable) was working in the building?

Was everything compartmentalized in the building like the elevators?

Also, to the architect site, he presumes the tons of paper created all the heat? That I thought was not plausible.

[philb]

9. In most offices, much of the paper is in metal file cabinets

it wouldn't burn readily

also even paper on book cases I don't think would create a hot fire,
and would be relatively hard to start

Are they suggesting that someone mistakenly furnished WTC with a lot
of extremely flamable materials. That would be pretty dumb.
If that was the problem why didn't they note who was to blame for improperly equipping the building with flameable materials.
The state offices here don't do such.

They had a major fire in WTC before that was worse than this one apparently, so they should have learned from that one.

[rumpel]

7. It is tower 1, he says the first one to get hit.

[philb]

2. So does this settle the issue of construction? Where does that leave us?

[rumpel]

8. No, only more questions.

I tend to think the core must have been one of the strongest in the building, just because of the amonut of vertical support beams. As they say, run to a bathroom during an earthquake. The thought being, that the ratio of space and load bearing walls and beams is greater than in an open room.
So, I think the core may not have needed additional concrete support and still be the strongest portion of the structure? (Even though I have yet to find the elevator shaft walls) This would be a question for an engineer.

But something occured to the core structure independently from the few floors that may have collapsed indeed.

If the "planes" were the delivery method of x to the core, it would explain that x traveled down the elevators and caused the damage this lady saw. (And for me x does not equal jet fuel).
However since that alone would not bring down the building other methods have been added, based on the sparks the firefighters saw, standing outside. The core could not be seen from the outside but the perimeter structure.

It says, they incorporated phone and cable into the floor during construction, and they were working on the electrical that weekend, that is too much of a coincidence for me.

[SittingBull]

4. GWashingtonBlog

has a link to construction video

http://www.georgewashington.blogspot.com/

[rumpel]

6. Interesting. I found something that describes the construction on a site

I think is geared toward kids but found it interesting, and it pretty much seems to be the same as the video you posted.

It only mentions concrete to have been used on floors, but that could amount to a quite a lot:

http://science.howstuffworks.com/wtc5.htm

"The construction process worked from the inside out. First, the crew built the steel framework of the inner core to a particular height, and then assembled the perimeter wall around it. The perimeter structure was actually formed from pre-fabricated sections of vertical columns attached to horizontal beams (called spandrels). The prefabricated sections were about 10 feet (3 m) wide, either two or three stories high, and weighed about 22 tons.

The floor structure was then installed between the outer perimeter wall and the inner core. The floors also came in pre-assembled sections, consisting of 32-inch-deep (81-cm) trusses topped with a corrugated metal surface. To finish each floor, the crew would pour concrete over the metal surface and top it off with tile. The floor sections included pre-assembled ducts for phone lines and electrical cable, to make things easier for the electricians who would come in later. After the steel structure was in place, the crew attached the outer "skin" to the perimeter -- anodized aluminum, pre-cut into large panels."

It seems concrete over metal delays the heat from fires to reach the metal, but engineers seem to think this to only last a few hours. But this probably has to be checked into.
Some think that the floor trusses buckled and came loose from the outer walls and the floors collapsed that way.
Yet, the center of the building was independent from this perimeter structure and I have a hard time envisioning how those floors can simultaneously bring down the core structure.