Wouldn't the idea of moving the anchor points as far away from the tower as
possible (space allowing). I want to remember calculating that an anchor point
135% from the attachment height gives the least sway on a tower. That would
also give less downwards force than the commonly recommended 80%.
Please correct me if I'm wrong with the 135%.
Hans - N2JFS
-----Original Message-----
From: Grant Saviers <grants2@pacbell.net>
To: dw <bw_dw@fastmail.fm>; TowerTalk <towertalk@contesting.com>
Sent: Sat, Feb 6, 2016 1:14 pm
Subject: Re: [TowerTalk] [Bulk] Military mast and guy-wire tension?
comments in line
On 2/6/2016 7:41 AM, dw wrote:
>
> And there is some concern about tower failure due to downward
> compression from over-tightening?
Yes. Two of the simple failure modes are exceeding the compression
strength of the tower leg and column buckling of a thin slender column.
The initial tension is added to the tension created from wind forces so
does reduce the maximum load permitted from wind. Towers have to lean a
bit for the tension in the guy to increase, which offsets the wind
load. The tension in the guy generates a horizontal force to oppose the
wind load and a vertical force which increases the tower compression
loads. Simple geometry can be used to calculate those forces. Keeping
towers and masts straight ("in column") is what multiple guys levels do,
otherwise they would buckle with just a top guy.
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