>>> Putting guys on will inevitably increase the compression loads on
>>> the downwind side a bit (from the vertical component of the
>>> tension in the guy, even if slack when unloaded, they will
>>> develop tension under wind load).
>> BTW, could you clarify that comment a little? I think the peak leg
>> compression (which occurs during strong wind in either the guyed
>> or unguyed state) is lower when guyed (reasonably), and you
>> yourself worked that out with an example a couple years ago, and
>> which seems obvious to me.
> the guy has some non zero tension, which has to resolve into a
> horizontal component (resisting the wind force) and a vertical
> component (pushing down on the leg). The wind force also bends the
> tower in the downwind direction, creating a compression load. And
> gravity. However, the bending load will be reduced by the horizontal
> force from the guy. So you can probably figure out an arrangement
> which either improves or worsens things.
So it's not inevitable then.
> If you throw in the wind loads on the tower itself, and the
> possibility of multiple guy levels, it gets pretty complex.
Complex yes, but the more guys (up to a point) the better I think.
On guyed towers, you see a pattern develop after seeing a lot of them.
This is really simplified but: 12" towers like to be guyed every 30'
with 3/16" wire, 18" towers every 40' with 1/4"-5/16", 36" towers every
60-80' with 3/8"-1/2", etc.
I think this gives us clues about what would be appropriate guying on a
self supporter. The upper bays would be closer spaced and use smaller
wire. If you keep the tower relatively vertical, straight, and untwisted
during winds, then it will survive.
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