[Phys-L] Re: Here we go again. WTC brought down by aircraft, not.

[Bernard Cleyet <anngeorg@PACBELL.NET>]

"Andre Marshall, a professor in the University of Maryland’s department
of fire protection engineering, offers the case of fire protection
codes, which are determined by panels representing ..."

Brian!

I'm not sure why you quote Dr. Marshal in reference to the BYU Prof.


bc, recovered from a "clean" install of OS X.


p.s. "... which a  single kick of a boot is sufficient to puncture. No
aircraft required."

If I remember correctly this saved some lives.  To gain access to the
stairs some broke thru the drywall.   Furthermore, I now, after your
mind jiggle, remember that asbestos was removed for the reason you gave.




Brian Whatcott wrote:
> At 01:06 AM 11/17/2005, you wrote:
>
> >  Dr.Marshall notes
> > the non-standard construction of the towers, whose truss system was
> > devised for  convenience during construction " the trusses were
> > lightweight and easy to raise  hundreds of feet in the air during
> > construction.
>
> ///
>
> > bc
>
>
>
> The floor trusses were welded tube. The design was pushed through
> despite the designers' reservations. A single person with a step ladder
>   and a hack saw would be capable of destroying the truss's integrity.
> No explosives required.Some of the spray insulation was
>   subsequently removed as a health hazard.
>
> The crucial fire resistance of the center pillar intended to carry the
>   gravity load  was unprotected plaster board - which a
> single kick of a boot is sufficient to puncture. No aircraft required.
>
> I take it that a physicist such as a BYU physics prof might also ask for
>   further investigation if he heard that a decent wood pillar is more
> fire-resistant than a steel rolled section of equivalent compressive
>   strength.
> That is to say: expertise in one field does not necessarily transfer.
>
>
> Brian Whatcott    Altus OK    Eureka!
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