My reference for noting that guys go slack is the K7NV FEA tower study.
While Kurt doesn't note the stress in the downwind guys the lean of the
tower at the top is pretty convincing to me that they slack. For 100'
tower the top moves 15 to 18" downwind for embedded base and as much as
54" a for pier pin base. While the wind loads in the study are high,
nothing fails in these models.
For big commercial towers with very heavy guys/ft I have no opinion.
http://k7nv.com/notebook/towerstudy/towerstudy1.html
Grant KZ1W
On 9/23/2017 22:59 PM, Roger (K8RI) on TT wrote:
It depends on the wire (size, length, composition, and the tension. I
used to regularly climb a 200' commercial tower that had 1" wire rope
for guys. there was an 18" tall, guy attachment point (don't remember
the height) Those guys would ring like a tuning fork when struck with
with a metal tool. it was way above 440
Hz. That kind of vibration will unscrew a lot of hardware, but not
with that kind of tension. The tower was a very solid 2' on a side in
20' sections, down onto an elevated pier pin base. The elevated base
was a good 6' on a side. The pier pin was about 7' to 8' above ground.
I have no idea as to how deep the concrete went.
Turnbuckles on 1" guys are BIG!
73, Roger (K8RI)
On 9/22/2017 Friday 8:04 PM, Steve Maki wrote:
On 9/22/2017 19:36 PM, Grant Saviers wrote:
At the specified torque values for structural bolts, the fastener is
far less likely to loosen. That isn't the static load in a
turnbuckle which is exposed to many of the conditions that cause
common fasteners to loosen.
You would think so. But guy wires (and turnbuckles) seem to be under
a different dynamic situation than nuts and bolts in a motor for
example. Vibrations are relatively slow, and tension never nears zero
in a system with proper pre-tension. I think.
-Steve K8LX
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