Doug wrote: "...leg compression will be increased with properly tensioned
guys." Well, of course it will.
But why do guys on a self-supporting tower have to be "properly tensioned"?
I thought they would be just for "insurance", a little extra support when
there's a little extra wind, or as a last stop-gap against a catastrophic
failure, or with aluminum towers, to limit the motion that "eggs out" the
bolt-holes. Why not make such guys "snug" but not "tensioned"?
73, Jerry K3BZ
----- Original Message -----
From: "Doug Renwick" <ve5ra@sasktel.net>
To: <towertalk@contesting.com>
Sent: Saturday, April 09, 2005 4:49 PM
Subject: Re: [TowerTalk] Guying a self-supporting tower
> We are finally getting a technical discussion on this topic.
>
> K7LXC@aol.com wrote:
>
> > The big problem with guying self-supporting towers is that the guys
have
> > the potential to increase the leg compression preload when properly
tensioned.
> > And as the leg capacity is the primary factor for tower strength, adding
> > additonal compressive force can lead to failure when a big windstorm
blows through
> > and the leg strength is exceeded.
> >
> Certainly leg compression will be increased with properly tensioned guys.
> I have believed that tower failure (guys remain intact) will be caused by
> torsion or twisting action on the tower, not by compression failure.
Someone
> with actual failure experience should comment on this belief.
>
> > Delhi towers are sort of a special case. Yes, they're the classic BX
> > design and include straight sections along with the tapered ones and,
yes, the
> > manufacturer does say "Guy wires must be used for larger loads or if
straight
> > sections are added".
>
> I do not believe that Delhi towers are a special case...they have cross
arms
> and three legs and can be tapered or straight like so many other designs.
> They are not heavy weight sections, but they will take a lot of
compressive
> forces on the legs.
>
> > No other self-supporting tower or manufacturer makes that kind of a
> > statement or suggests guying the tower.
>
> Can you provide the self supporting tower manufacturers that state their
towers
> are not to be guyed? And can you provide supporting references? And if
there
> are some that do say 'do not guy', I would be interested to find out why
based
> on engineering reasons.
>
> > They're designed to be self-supporting and guying them goes against
their
> > engineering and design.
>
> Explain please how guying these towers 'goes against' their design and
> engineering. It's obvious that they are designed and engineered to be
> self-supporting. How does guying degrade their design?
>
> --
> Doug Renwick VA5DX
> PO Box 50, Clavet, Saskatchewan, Canada S0K 0Y0
> VE5RA@sasktel.net
> First VE5 5BDXCC, 160M DXCC & 9BDXCC
> What profit it a ham if he gains all the awards yet forfeits his soul?
> I'll run the race and I will never be the same again.
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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