[UK-CONTEST] Guying a "lugless" Versatower

[Don Beattie]

May I add to this ?

We live here on top of a hill, with a 30 mile view to the SW (whence, 
generally, cometh the wind). Both towers here have been up for ten years, and 
the HD 80ft one is always guyed and normally up about 65ft. I raise it (in 
non-storm weather) to full height. It carries a ten-element 10-40m yagi. The 
guys work at both heights through use of strong commercial-grade galvanised 
lifting chain for the bottom 15ft or so, which allows the right link to be 
selected after raising or lowering. It is (touch wood) unmoved by the large 
gales we get here. Guying is Phillistran at three levels.  The 60ft standard 
tower sits at about 45-50 ft unguyed all the time, with a 3 ele SteppIR. I 
generally keep it with the bottom of the top section sitting in line with the 
top of the bottom section, meaning there is a good degree of overlap.

Based on my experience, out of caution I would not leave the 80ft HD tower guyed 
at full height in the worst gales, but it has survived some really big blows at 
65ft. The key thing for me is to turn the yagi to offer least wind resistance 
during a gale. And I agree with Chris - I would never try to adjust it when it's 
blowing, nor would I consider leaving it at 65ft unguyed in strong gales. When 
it's up at 80ft, I keep a regular eye on Wind Map ( 
http://www.xcweather.co.uk/ ) which I find really helpful. But even at 80ft, 
when a big contest is afoot, I would take a risk and leave it there, even in 
a gale. It's just my natural caution that makes me lower it at other times.

The spec says tha an 80ft Versatower can be left at full height with 5.2 sq ft 
of top load at 85 mph unguyed. Not my idea of fun but...a guyed tower can take 
17 sq ft at 100 mph.

Just my 4d-worth.

Don, G3BJ

 



________________________________
From: Chris Tran GM3WOJ <zl1ct1 at gm7v.com>
To: Regwoolley at aol.com; uk-contest at contesting.com
Sent: Monday, 29 August, 2011 7:46:27
Subject: Re: [UK-CONTEST] Guying a "lugless" Versatower

>
> I must add anyone that would want to leave a tower fully up in high winds
> is barking mad. I would much prefer to get the thing down the slow way
> than seeing it crash the fast way!
>
> Reg G8VHI
>

Hello all

Sorry to disagree Reg but the worst thing you can do is to try to lower a
guyed crank-up tower in a high wind.

Let's be clear - I am talking about a tower guyed in the correct places,
with properly tensioned wire rope guys and antennas which do not exceed the
recommended head loading for the tower.

As soon as you start to crank the tower down, the effect of the guying
disappears immediately and the tower is very vulnerable to the wind forces.

So the best advice is to do the guying job properly and sleep easily through
every storm (OK maybe with one eye open watching the tower!)

73
Chris
GM3WOJ / ZL1CT

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