The following was Steve's question to me and my response which was snet off the
reflector.
Steve said:"Bill,
Are you an engineer? If so, can you devise a case, using a reasonable
tower and guy system, which contradicts my (and others) "theory"? I've
put this to a few engineers, and they haven't come up with one. I'd be
the first to shut up about it if an example could be shown...
Thanks,
Steve K8LX"
My response:
"Steve
Yes I am an engineer but I am not a structural engineer. But I do know
enough not to make assumptions about the consequences of guying a
self-supporting structure without knowing more about the effect the guying
has on the buckling mode. Just saying that you had talked to an engineer
does not mean anything to me if the engineer is not trained structural
engineer and I seriously doubt a structural engineer would have passed off
your scenario so lightly. Such a statement is simply not proof that the
guying can be done safely.
For example I do know that the buckling mode will depend on the section
modulus, yield strength, induced compressive stress (when combined with the
shear stress and bending stress to produce the principle stress) and the
location of the guys with respect to the length of the guyed sections. Too
much stress with too little section modulus and yield strength over an
improper length will induce buckling, which is not the same as the simple
question of the stress at the base and is much more difficult to analyze.
I addition to being an engineer, I was the chief lawyer for CF&I Steel
Corporation earlier in my career and later the VP and general Counsel of
SAAB's onshore aviation operation. I also taught Aviation Law as a
professor of Flight Technology. I am very familiar with he issues
considered by companies that produce towers since CF&I was one of them. The
liability to a company for "failure to warn" is one way litigants claim
liability against manufacturers. For that reason the warnings have to be
carefully analyzed and specific. I was, perhaps, better prepared than most
lawyers to do that as a design engineer (I helped design parts of the Boeing
747) so to suggest that the legal position of companies is just something
the lawyers cook up is pure nonsense.
So it is really up to you to prove that the guying can be done safely and I
don't think you have even come close. You apparently have no expertise and
have not given any credible evidence that anyone with approprite expertise
has made a considered evaluation of the subject and renedred a professional
opinion. Without that the willingness to accept your short-cutted theories
is foolhardy.
73
Bill
W7VP"
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