[Boatanchors] Guy Wire Insulator Placement

[Glen Zook]

What I am using is personal experience.  In each case where I know of problems with an aluminum tower, the tower was installed using the manufacturer's recommended procedures.  In each case the wind load on the tower was less than the maximum rating of the tower.  In each case, the tower "buckled" at about the half-way point.  That is, there were no problems with the base installation.

These towers were installed in north Texas (Dallas, Texas, area) where the wind speed does, on occasion, get above 70 mph.  In fact, every few years, the wind speed can go over 90 mph.  These are "straight line" winds and not tornadoes.  A tornado, of course, is a completely different matter.

Obviously, there are different manufacturers of aluminum towers and, probably, different specifications that must be met in different countries.  As such, I have no idea as to if the aluminum towers sold in Australia are the same as those that were sold in this area.  But, I do stand on my comments based on my experiences.

In my professional experience as a telecommunications consultant, I have had quite a number of towers installed from less than 100-feet to over 500-feet.  As such, I do believe that I do have at least a "little" experience with different tower types.  Those towers ranged from guyed to self-supporting and I would never recommend using an aluminum tower!
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: "brianclarke01 at optusnet.com.au" <brianclarke01 at optusnet.com.au>
To: Glen Zook <gzook at yahoo.com>; Rob Atkinson <ranchorobbo at gmail.com>; Bill Stewart <cwopr at embarqmail.com> 
Cc: boatanchors <boatanchors at mailman.qth.net> 
Sent: Thursday, July 25, 2013 5:08 AM
Subject: Re: [Boatanchors] Guy Wire Insulator Placement
 


With all due respect, Glen,


Usually, I find you give fairly good advice.


But this diatribe you have contributed has no engineering merit whatever. You have given no statement of design for dead weight, wind loading, erection, ground support ...  I have designed towers using both aluminium and steel. Those two metals have different crush strength, sheer strength, fatigue resistance, weight, ease of fabrication, cost - I could go on.

To everyone else on this list, get an engineer to assess and certify any proposed tower you want to erect.

73 de Brian, VK2GCE
BEng, PhD, Fellow IEAust 



>----- Original Message -----
>
>From:
"Glen Zook" <gzook at yahoo.com>
>
>To:"Rob Atkinson" <ranchorobbo at gmail.com>, "Bill Stewart" <cwopr at embarqmail.com>
>
>Cc:"boatanchors" <boatanchors at mailman.qth.net>
>
>Sent:Wed, 24 Jul 2013 10:37:12 -0700 (PDT)
>
>Subject:Re: [Boatanchors] Guy Wire Insulator Placement
>
>
>Unfortunately, aluminum towers are just not as sturdy as steel towers!  A while back, I helped a local amateur radio operator get his quad out of his neighbor's tree when the aluminum tower failed in a windstorm.  The load on the tower was significantly LESS than the rating.  I have heard of similar problems with aluminum towers elsewhere.
>
>Also, a 60-foot self supporting tower  that can support any reasonably sized yagi is going to be pretty wide at the base.  Most towers are not installed using "Johnny balls"!  The vast majority are installed using a section installed in concrete poured in a hole against undisturbed soil.
> 
>Glen, K9STH
>
>
>Website:  http://k9sth.com
>
>
>________________________________
>From: Rob Atkinson <ranchorobbo at gmail.com>
>To: Bill Stewart <cwopr at embarqmail.com> 
>Cc: boatanchors <boatanchors at mailman.qth.net> 
>Sent: Tuesday, July 23, 2013 10:20 PM
>Subject: Re: [Boatanchors] Guy Wire Insulator Placement
>
>
>If you only want to go up 50 or 60 feet, I'd consider a free standing
>tower  Then johhny balls and guys are a moot subject.
>I'm told the Mosely TA33 is a good beam, but only covers 10, 15 and
>20.   Have you considered a quad?   Work well at low heights; small
>turning radius.
>
>A 40 foot free standing aluminum tower could be wenched over for work
>on the ground.
>
>important question re tower height:  what is your local topography
>like?   i.e., tower down in a hole; up on a hill, on flat ground...?
>
>Just some ideas but disclaimer:  I have never owned a tower, never
>owned a beam, rotator, any of that and never been a big DX chaser or
>high band op.  just a dipole here at 35 feet for the high bands.  All
>information above is from listening and reading.
>
>One thing I'd avoid is those cable/pulley crank ups.  Unless you are a
>professional mechanic and really know how to treat them, I'd stay away
>from them.
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