Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Is this news?

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I participated on a WTC panel in New York in 2002 discussing WTC.  WTC 7 was a bit of an issue in that there was no significant impact from airplanes or WTC 1 or WTC 2 to cause the collapse.  There were a lot of very sharp people that looked into the collapse including Arup engineers, Ron Hamburger, and Gene Corley to name a few.  As usual, I was like a kid studying at the knee of the great ones.  Being on the panel just gave me a good seat. 
The investigators had a pretty good idea about what happened to WTC 7, but it took a while to sort it all out.  It was troubling to the extent that One Meridian and First Interstate were among the classic high rise fires that had devastating long lasting fires, but no collapse. 
WTC 7 was problematic because it did not take that long (relatively speaking) for the fire to cause collapse.  And it was the first high rise collapse caused by a fire.  The crux was 2 fold.  One - the transfer truss was acting to transmit column loads and two - the fire proofing of the truss may have had holidays due to construction activities.  There was fuel in the basement that was the source of the fire, and once the truss local temperatures achieved the point to initiate yielding, there was no stopping it. 
This issue had the potential to legitimately change the building and fire codes.  WTC 1 & 2 were anomalies.  We are not going to make airplane impact a design load case for every building over 10 stories high.  WTC 7 had some legitimate building code concerns. 

Harold Sprague

> From: mblangy(--nospam--at)
> To: seaint(--nospam--at)
> Subject: Is this news?
> Date: Thu, 21 Aug 2008 12:08:25 -0700
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at:
> *
> * This email was sent to you via Structural Engineers
> * Association of Southern California (SEAOSC) server. To
> * subscribe (no fee) or UnSubscribe, please go to:
> *
> *
> *
> * Questions to seaint-ad(--nospam--at) Remember, any email you
> * send to the list is public domain and may be re-posted
> * without your permission. Make sure you visit our web
> * site at:
> ******* ****** ****** ****** ******* ****** ****** ********

Get thousands of games on your PC, your mobile phone, and the web with Windows®. Game with Windows