On 4/2/2012 8:57 PM, Greg wrote:
>
> This I guess answers a question I was going to ask. I have 20 ft of
> r25 bracketed to my garage at abt 12 ft. My plan was to put another
> 10 or maybe 20 ft on it unguyed and with a haze for a 6m5x and as a
> support for an 80m edz of abt 340 ft. No climbing would be needed
> except for installing the two more sections. I was not planning on
> guying this but I guess I should. I could probably do temp guys for
> installation.
>
Go to http://www.rohnnet.com/rohn-g-series-self-supporting-tower and
click on G series self-supporting Brochure Download. Also look up 25G
bracketed towers. Between the two they'll basically tell you what you
can and can't do. Remember too that ROHN does have a safety factor
built in.
I don't claim to have always done things the smart way as the following
two links will attest. The tower is a 90' American Steel. It is neither
as well constructed, or out of as quality materials as the 25G and might
be 1/2" to 1" narrower than the 25G. It's also 24" between the cross
braces. I don't think there was a straight section left in that tower
at the time these photos were shot. Oh! The tower was also "over guyed"
using 1/4" wire rope instead of the 3/16" which added considerably to
the vertical load and particularly the load supported by the base. IIRC
the legs on the bottom two sections were "belled" together and required
a jack to get them apart.
http://www.rogerhalstead.com/ham_files/tower8.htm
And zoomed back enough to show the whole tower.
http://www.rogerhalstead.com/ham_files/tower9.htm
BTW that was the day I decided to replace that skinny little tower with
a 45G. <:-))
73
Roger (K8RI)
>
> 73
> Greg
> AB7R
>
> On Apr 2, 2012 5:06 PM, "K8RI" <K8RI-on-TowerTalk@tm.net
> <mailto:K8RI-on-TowerTalk@tm.net>> wrote:
>
> On 4/2/2012 7:05 PM, Jim Hoge wrote:
> >
> > I can only imagine how wallowed out the bolt holes must be on a
> self supporting 40' Rohn 25G tower. I won't climb more than 20'
> of unguyed 25G. The "I've done it for years" statement is not an
> acceptable reason for unsafe practices. Temporary guys are a must
> when working on that tower. It only takes one whoops to make it a
> really, really bad day.
>
> I'm used to climbing 100' of 45G guyed with 6000# test Phillystran
> which
> is rock steady in a 20 or 30 MPH wind. I have 40' of a 50' 25G up.
> It's
> bracketed at the roof line and guyed with 5/16" synthetic temporary
> lines. just below 40' and at 30'. Technically it could go that high
> without guys. I find it to be "unsteady" at 40 feet with guys on
> a calm
> day. No way would I climb 40' of the stuff unguyed, let alone more.
>
> The top section is ready to raise, has the guy brackets in place, and
> all I have left to do is calculate the lengths of the Phillystran guys
> and prepare them.
>
> Call me chicken if you'd like, but I've been climbing for over 50
> years
> and have never once gotten hurt on a climb.
>
> We used to live a few hundred yards West of a commercial tower. I had
> permission to climb it as I often worked on it. Many an evening I'd go
> up that thing just to shoot photos of the sunsets. I like to
> climb and
> I like to fly aerobatics, but I do not like to take unnecessary
> chances.
>
> 73
>
> Roger (K8RI)
>
>
>
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