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Re: [TowerTalk] tower specs/not wind loads

Subject: Re: [TowerTalk] tower specs/not wind loads
From: "Pat Barthelow" <>
Date: Tue, 24 Jan 2006 13:15:34 -0800
List-post: <>

Been there, done that, on a Rohn 25, 50 footer free standing, of a ham 
friend, donating some tower work....The tower was professionally installed, 
with what looked like  a 5' by 5' square concrete base.  I did not know how 
deep the concrete was.  I assumed the engineering was right because the 
tower was installed by a well known local 2 way radio business...
I worked on it from time to time, on my friend's  TA 33 beam, and was 
DEFINITELY  uncomfortable with the sway and 'exposure' I felt 50 ft up, 
unguyed.  Kept telling myself quietly...Well this WAS installed by a 2 way 
contractor.. must be right.....I later was told that there was no official 
Rohn specs for any unguyed 25 tower, but that it was not uncommon to have 
done on a case by case basis (with case by case engineering) to heights of 
40 ft.   Gave me the Willies......haven't been up that tower since.

73, DX, de Pat Barthelow AA6EG

>From: "A.J. Farmer (AJ3U)" <>
>To: Steve Shelton <>
>Subject: Re: [TowerTalk] tower specs/not wind loads
>Date: Tue, 24 Jan 2006 16:00:04 -0500
>On 1/23/06, Steve Shelton <> wrote:
> > Hi, I am fairly new to towers and I have tried to research information
> > on rohn's 25, 45 and 55 towers.  I have found quite a bit of information
> > on these towers but not the exact answers that I am looking.  One of my
> > questions is what is the maximum safe height on these three towers
> > without guying?  How much weight can they handle guyed or unguyed? The
> > reason I ask is that I do a lot of tower climbing and often run into a
> > rohn 25 that is not guyed.  Most are only 40' but some as high as 80'
> > and without guy wires these towers do a lot of swaying.  I would feel
> > more comfortable on these particular towers if I knew for sure that an
> > extra 200lbs harnessed to the side of this tower is not going to be the
> > stick that broke that camels back.  Thank you for any information that
> > you have.
>C'mon fellas - none of you answered this guy's question but instead
>hijacked the thread and started on about other things not even related
>to his question...
>Steve, my understanding is that the maximum freestanding height of
>Rohn 25G is 30 to 40 feet.  I would assume that this limit allows for
>an average (200lb?) climber doing maintenance, but I have always
>wondered the same thing.  I don't know about 45G and 55G, but I do
>know that they were designed as guyed towers, not freestanding.
>Everyone talks about wind load, but what about the load of somebody is
>hanging off the side near the top?  How does that compare?  I don't
>have the engineering experience to do this calculation.  Perhaps
>someone on this list knows how to do this?  If so, then that load can
>be compared "apples to apples" with a wind load, right?    Some hard
>numbers sure would make me feel better about being up there...  I have
>a 30 foot freestanding 25G tower and it makes me nervous when it sways
>when I'm on top.  I can't imagine being up 80 feet unguyed...  You are
>a brave man, indeed!
>A.J. Farmer, AJ3U


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