It's the difference between "thinking it's strong enough" and "knowing it's
strong enough"..
And that difference affects the assessment of the risk you want to accept.
The former has more risk than the latter. The difference may not be
significant in some situations (a tower out in the lower 40 with nothing
around) and may be significant in others (a tower in a suburban backyard
with litigious neighbors).
In many situations, analysis may not be the way to approach the risk
problem. Proof testing may be a better approach, for something that is hard
to analyze.
Experience is basically a form of proof testing. If you build 1000 windmill
towers with a back of the envelope sketch and none fall down, you figure it
must be a strong enough design. What you don't know is how close you are to
the ultimate failure, nor if your design is overdesigned (much more strong
than it needs) or inefficient (makes poor use of material.. weak for the
amount of material). However, if materials are cheap, and labor is cheap,
maybe coming up with the most efficient engineering design isn't sensible.
If you're trying to sell a product in a competitive market, or install that
product in a highly regulated environment, what's sensible (or required)
changes.
----- Original Message -----
From: "Jerry K3BZ" <k3bz@arrl.net>
To: "David Robbins K1TTT" <k1ttt@arrl.net>; <towertalk@contesting.com>
Sent: Sunday, April 10, 2005 8:24 AM
Subject: Re: [TowerTalk] Guying a self-supporting tower - Yes
> That would be the "sensible" conclusion if one is an engineer or if one
> believes that only engineers can reach "sensible" conclusions.... and I
say
> that with all due respect. Maybe it's just that I'm not smart enough to
> understand what's being said, but I sometimes think engineers over-analyze
> things to such an extent that any "meaningful" conclusions get lost in the
> arithmetic... 8^)
>
> 73, Jerry K3BZ
>
> ----- Original Message -----
> From: "David Robbins K1TTT" <k1ttt@arrl.net>
> To: <towertalk@contesting.com>
> Sent: Sunday, April 10, 2005 7:25 AM
> Subject: Re: [TowerTalk] Guying a self-supporting tower - Yes
>
>
> > The only 'sensible' conclusions to this are the following:
> >
> > 1. do what the manufacturer says for 'standard' installations
> > 2. do what a qualified mechanical engineer who has performed the
analysis
> on
> > the specific design says for non-standard installations
> >
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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