| Time
To Look Ahead
I am uneasy about
reading articles that appear in various newspapers on the
collapse of the World Trade Center’s twin towers. As
your story, "Engineers Seek Corrections," notes,
expert engineers promulgate their own theories on the causes,
and newspapers that are hungry for some "great"
and preferably "scandalous" revelations are all
too ready outlets (ENR 11/11 p. 11).
I was interviewed
[by a newspaper] on the day of the collapse and have had only
the benefit of the pictures seen on television. My opinion
was, and still is, that first, the impact knocked off all
the fireproofing material from the structure. Then, the enormous
fire softened up the columns to the point where their load-carrying
capacity was fatally compromised.
I am aware that
some engineers tend to blame the floor trusses and/or their
connections to the exterior wall. The claim is made that as
the floor trusses collapsed under the fire, the exterior walls
became unbraced and collapsed in a buckling mode of failure.
I believe, however, that this is the argument to which there
is a classical "So what?" answer. To the best of
my knowledge, no one has yet suggested that if rolled steel
beams were used as floor members, the structure somehow could
have survived the attack.
Somewhere in this
whole process, we seem to have lost sight that at the time
of design and construction, the concept and its particular
details all were great engineering achievements. The towers
stood for several decades and would have continued to serve
as mileposts for great structural engineering for many more
decades, if not centuries, had they not become victims of
madmen.
I would, however,
like to see a symposium where the profession could discuss
the issues. Not a post-mortem of what is the belief of one,
or another, engineer on the collapse. It would be much better
if we could get together and discuss the following proposition:
"Is it possible to design a tower building that will
withstand the impact of a 150 to 200-ton firebomb traveling
at 400 miles per hour? Yes or no?" Then perhaps we may
see some advanced thinking done not over the past, but over
the future.
Open Competition Works
Again
It
came as no surprise to those of us at Associated Builders
and Contractors that a bidding system promoting free and open
competition resulted in a number of competitive bids on the
most recent Woodrow Wilson Bridge replacement project contract
(ENR 11/18 p. 13).
The article notes
that Maryland officials can now breathe a sigh of relief.
We can’t help but think about the lost time and delays
that occurred as a direct result of Maryland Gov. Parris Glendening’s
(D) attempt to have a union-only project labor agreement as
part of the contract. With the threat of a PLA, only one bid
was received on the superstructure [and] it was not even in
the ballpark, so the process had to start over. It wasn’t
until the Federal Highway Administration [acted] that the
initiative was finally dismissed.
Before the state
and governor spend too much time patting themselves on the
back, the real thanks should go to the Bush administration
for recognizing and understanding the basic economic principle
that more competition brings about lower bids. Oh yeah, with
Governor-elect Bob Ehrlich (R) taking office, we won’t
have to deal with this problem again.
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