Mourning the Towers

From: Steven Hoblit

>Some relevant information:

http://www.panynj.gov/wtc/wtccomplex.htm

http://www.skyscraper.org/tallest/t_wtc.htm

WTC 1 and 2 were a hollow box variant. Despite the horrific degree of 
collateral damage from the collapse, it could have been a lot worse. There 
was a very specific decision not to include as much masonry as similar 
structures have.

Some sites are understandably down, either in deference to the victims and 
families of yesterday's events or to add further information.

(example: http://www.m-yamasaki.com/)

Visiting lower Manhattan in high school and college, I used to lie on my 
back in the plaza at night with friends and watch the towers sway, 
occluding stars on either side as they slowly moved back and forth.

Going up to the top (to Windows) via the express elevators was the most 
enjoyable elevator ride I've ever taken. You could jump at the end of the 
ride up and go flying a few feet off the floor.

I hope the area becomes a memorial. There is no way that all people in 
there will be found. Probably some who will never be accounted for: those 
without immediate family, or whose place of work was family. Perhaps a 
decision to do this can start to provide a modicum of closure to those 
whose loved ones have disappeared.



From: Declan McCullagh 
To: politech@politechbot.com
Subject: FC: Pat Farrell on "architectural implications" of WTC attack
Date: Tue, 11 Sep 2001 20:59:04 -0400

[Also see John Young's note below. --DBM]

***********

Date: Tue, 11 Sep 2001 17:31:48 -0400
To: Declan McCullagh
From: Pat Farrell 
Subject: Architectural implications of WTC attack

Hi Declan,

I've written up a small article on politics and technology of architecture
relating to today's WTC destruction. I wrote it because I see all the
mass media hand wringing and wailing as missing the key point.
A pointer to it in politech, or feel free to take it all if you think
anyone would be
interested.
  
URL is http://www.pfarrell.com/rants/archtower.html  
---


Date: Tue, 11 Sep 2001 13:25:30 -0700
From: John Young 

The '45 Empire State Building crash is oft studied in architectural
and structural engineering to learn why the building withstood the
hit. The plane was a B-24, I believe, but in any case a much smaller
craft than the ones which hit the WTC and the Pentagon. The '45
plane's engines did penetrate the building, shooting out the far side
and falling to the ground and killing passersby, but most of the plane
remained inside the structure for it was made of far more fragile
materials than a building. A relative small amount of damage was
done to the structure of the building though fire was devastating,
especially from flaming gasoline cascading inside.

The fireball that shot from the second WTC tower hit, opposite
where the jetliner penetrated, blew out windows and perhaps part
of the latticework exterior structure. Flaming fuel probably
cascaded down the shafts of elevators and ductwork and
stairwells whose fire-protection enclosures would have been
destroyed by the explosive crash and ballistic heavy plane
parts. These fuel flames, and fires started from them,
would have weakened interior structural support beyond
protection provided by code-required fireproofing. Once
the interior structural supports were weakened, and
the exterior lattice lost its integrity collapse was inevitable.

I modify my first evaluation to speculate that the interior
supports appear to have given way before the exterior lattice
(whose girdle of closely-space columns and thin vertical
windows between gave the buildings a unique look compared
to use of large panes of glass elswhere)  The lattice amazingly
contained the interior collapse and the whole mess dropped
vertically, almost, as newscasters report, as if executed by a
demo expert.

I did not expect the Twin Towers to collapse. To suffer terrible
fires and localized interior damage but not total collapse. The
first was unbelievable, and as I said, I thought only the portion
above the crash fell. Then the smoke cleared momentarily
to show the totality. Then the second tower, collapsing in a
near-perfect copy of the first. The sudden dropping of the
floors above the crash, that impacting load overpowering
the remaining system, and the straight drop collapse, neither
tower falling much to the side, indicated what had happened.

Close-ups of the exterior show the latticework bridging the
crash penetrations, reminding of sales pitches from the
19th Century when cast-iron manufacturers promoted
their architecture with structural compoments missing
with no apparent destabilization -- the load automatically
shifting to remaining components. Their prognostications
failed at the first intense fire which overheated and cracked
the cast iron, sometimes collapsing more quickly than
predecessor masonry bearing wall and wood floor system
composites.

Humbling news: My daughter is safe and sound. She heard the
first crash and saw the tower blazing on the way to work and
thought it was merely (!) a fire. Her office remained at work
unaware of what had happened, and was happening, without
TV or radio, until telephoned from overseas headquarters
which ordered everyone home. At first the office dismissed
the alarm, saying, hey, this is New York, no problema, we
have work to do, our customers come first, sure that would
impress the venal bastards. Then someone was sent
outside to check reality.

---

From: "Kent, A.D." 
Subject: RE: Eerie                                                                        Date: Wed, 12 Sep 2001 08:59:02 -0500
X-Mailer: Internet Mail Service (5.5.2653.19)

Response from one of the WTC architects regarding structure failure...

http://www.jpost.com/Editions/2001/09/12/News/News.34647.html                             
---

Towers Collapsing
-------------------
According to NYTimes, the fire's melted the floor supports:

"The high temperatures, of perhaps 1,000 to 2,000 degrees, probably
weakened the steel supports, the experts said, causing the external
walls to buckle and allowing the floors above to fall almost straight
down. That led to catastrophic failures of the rest of the buildings."

entire article:
http://www.nytimes.com/2001/09/12/nyregion/12CENT.html




From: "Kent, A.D." 

Response from one of the WTC architects regarding structure failure...

http://www.jpost.com/Editions/2001/09/12/News/News.34647.html