OK, guys. As the instigator of this thread (which has been interesting, to
say the least) I'd like to provide an opportunity to review my original
post, submitted as a challenge (tongue-in-cheek) to K7LXC's notion that the
'Prime Directive' can be circumvented if we "over-engineer". It's
available below.
Please note the following:
1. The main point of my post was that intuition, not supported by analysis,
could lead to unintended consequences. The guyed self-supporting tower was
used as an example. It seems that everyone, even Yuri (the strongest
challenger), in plenty of "thoughtful dialogue", has validated this premise.
Thanks!
2. I'm an engineer, too; but of the electrical/electronic persuasion.
Although I can understand every line of the stress analysis provided with my
self-supporting tower, I would never attempt to GENERATE such an analysis.
It's out of my field. That would be like asking an allergist to fix my gimpy
shoulder. Those who wish to re-engineer outside their field should
understand and accept the consequences. For this particular example, if you'
re a stress guy, knock yourself out. Otherwise, you might miss the
subtleties.we have discussed a few: buckling, point loads, shear strength,
load distribution as a function of deflection, and lumped-constant moments
(using an electrical analogy here). There may be others. Anyone have a
finite-element analysis program?
3. I n a subsequent reply to Jerry, K3BZ (and the List), I acknowledged the
presence of self-supporters for which the manufacturer permitted auxiliary
guys (presumably supported by analysis).
4. The final comment in my original post was to do your homework first,
before relying on intuition alone. Some of us have the credentials, but most
don't (I'm included here). When it comes to safety issues, the laws of
physics don't make special allowances for amateurs.
5. If I had the opportunity to rewrite the original post, I would have used
the cable-supported crank-up as the main example rather than the monolithic
tower. WITH THAT EXCEPTION:
I'm stickin' by my original post, and thanking all participants for sharing
their thoughts.
Despite some occasional emotion, there has been mostly straight thinking in
this thread. That's Towertalk in action!
73,
Chuck, N4NM
(Hoping we can put this to bed)
N4NM's original post:
Steve wrote (referring to breaking the 'Prime Directive'):
>> I'll never
>> discourage someone from over-engineering something.
Except when a counter-intuitive "improvement" obeys the 'Law of Unintended
Consequences'. For example, adding guy wires to a self-supporting tower.
Sometimes you just gotta do a little research first. As someone recently
said, "Caveat Amateur"!
73,
Chuck, N4NM
|