On Mon, 12 May 1997 11:59 EST dhand@mdi.com (David Hand) writes:
>.¡¦Ø¸ dhand@DS9.MICRODES.COM
>
>I was reading the thread on guy tensioning and a couple questions
>came
>to mind ...
>
>If the guy points are not equal distance from the base (my case)
>wont the tension need to be unequal?
>
>Given that each guy is going to exert a horizontal and a
>(compressive) vertical vector component .
>If the guy angle isnt equal (I.E. some guys are steeper than
>others )
>the vectors will add up differently so ....
>
>If the lateral components are equal, the compressive force
>wont
> be and vice -versa.
>
>Humm .. I think I just made a real good case for setting them up to
>all
>be equal .... but I really
>cant see that working out here.
>
>
>Second Question ....
>
>If you used 4 guys with equal spacing and equal tension on all
>how
>would you attach the guys to the tower to equalize the compression
>on
>each leg? If you attached two guys to any leg that leg would
>have twice the compression on it, or am I OTL (out to lunch)???
>
>I suspect that the lateral forces should be equalized first then
>
>if the compressive load is
>with in some broad but unknown range your OK
>
>Anyone have any ideas??
>
>Dave WB4HYP
>
>
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>Submissions: towertalk@contesting.com
>Administrative requests: towertalk-REQUEST@contesting.com
>Problems: owner-towertalk@contesting.com
>
I don't see any need to equalize the compression on each leg.
If you are forced to use asymmetrical guy positioning, then
adjust tension to equalize the lateral forces. If you depart
significantly from the manufacturer's recommended layout, you
(or your PE) should calculate your worst case
leg compressive force (steepest guy, highest wind, worst wind
direction, max ice) to make sure you
do not exceed the compressive force spec for the leg, or the
tension capability of the guy wire, or any other tower specs.
Rohn recommends four-way guying on their foldover towers, and
they show two guys attached to one of the legs, so the
compressive forces exerted by the guys are doubled on that leg.
Consider the source of the above advice. I'm an electrical engineer,
not mechanical, but I got a "B" in Statics (34 years ago).
Dave Hachadorian, K6LL
k6ll@juno.com
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|