Hi Scott,
Yes, please share. I am very interested.
Tnx & 73
Bob KQ2M
From: K9MA
Sent: Saturday, September 21, 2019 12:57 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Fwd: Guy Wire Tension Calculation
Hi Hans,
By coincidence, I just finished doing the math, recalled from my statics
course some 50 years ago. 1.15 at 30 degrees is indeed the worst-case
factor. It's really a simple calculation, but I'm a bit rusty on this
stuff. I'll share the details, if anyone is interested.
73,
Scott K9MA
On 9/20/2019 23:57, Hans Hammarquist via TowerTalk wrote:
> Hi Scott,
> I don't have the reference but I did some calculations myself some years ago.
> I don't remember the exact numbers but the 1.15 factor is right. If that
> happens at 30 degrees or if it was 15 I can't recall, the 1.15 factor is
> correct.
> The explanation is that when the wind attacks the tower 30 degrees off the
> guy wire facing the wind, one of the guy wires, on the other side of the
> tower, will pull on the tower sidewise and will increase the tension in the
> wire facing the wind.
>
> Now, the 15% increase in the guy wire tension isn't that much. You,
> presumingly have a much larger safety margin, so an additional 15% should not
> be the factor, collapsing the tower.
> 73 de,
> Hans - N2JFS
>
>
> -----Original Message-----
> From: K9MA <k9ma@sdellington.us>
> To: towertalk@contesting.com <towertalk@contesting.com>
> Sent: Fri, Sep 20, 2019 10:30 pm
> Subject: [TowerTalk] Guy Wire Tension Calculation
>
> Does anyone have a reference for calculating worst-case guy wire tension
> for a 3-wire system? The only thing I'm unsure of is the effect of wind
> direction. One source states that worst case is for wind 30 degrees one
> side of a guy, and is 1.15 times the force with the wind aligned with
> the guy. The 1.15 factor is easy to calculate, but is that really the
> worst case?. It's also clear that, with the wind exactly between two
> guys, the tension in each is the same as when the wind is aligned with
> one guy. Whether 30 degrees really is the worst case direction seems a
> non-trivial calculation.
>
> Note that I'm not asking about calculating the effect of vertical angle,
> etc., as that's straight-forward. I'm just interested in the worst case
> horizontal component of guy wire tension as a function of wind direction.
>
> 73,
>
> Scott K9MA
>
--
Scott K9MA
k9ma@sdellington.us
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