There is actually more to it than that Jim. Whenever there is a combination
of a spring, a mass and a dampening source there is the prospect of dynamic
oscillation. In so cases the potential oscillation dies out in an
exponential decay in the same manner as an overdamped electrical transient.
(In fact the mathematical solution is exactly for a mass, spring and damper
as it is for a capicitance, resistance and inductance). In other cases the
oscillation can run away with iteslf such as what happened with the First
Narrows Bridge. Adding a spring without taking into condiseration the
dynamic effect is totally foolish. In the wrong wind with the wrong guy
tension it is possible to set up a destructive longitudinal oscillation.
More than likely the tower designers have taken that into consideration in
designing th guy system. I would never mess with their recommendations by
using a spring on the guys without a proper engineering analysis.
73
Bill
W7VP
----- Original Message -----
From: "jimlux" <jimlux@earthlink.net>
To: "Drax Felton" <draxfelton@gmail.com>
Cc: <towertalk@contesting.com>
Sent: Sunday, October 26, 2008 9:26 AM
Subject: Re: [TowerTalk] Spring between equalizer plate and earth anchor
> Drax Felton wrote:
>> A local ham told me to get some heavy duty hood springs from a
>> 1950-1960's
>> car and put them between my guy wire equalizer plates and earth anchors.
>>
>> This is to "prevent backlash" during storm force winds.
>>
>>
>>
>> Any thoughts on this?
>>
>>
>>
>> I think if Rohn didn't engineer it to work that way - then don't.
>>
>
> You're right.
>
> The fact that the guys aren't straight lines (they're catenaries) means
> that as the load increases they get a bit longer, just like a spring.
>
> Why put another device in series with the string? Just increases the
> number of things that can break.
> _______________________________________________
>
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>
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