[TowerTalk] Spring between equalizer plate and earth anchor

[Bill]

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 at earthlink.net>
To: "Drax Felton" <draxfelton at gmail.com>
Cc: <towertalk at 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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