Towertalk
[Top] [All Lists]

Re: [TowerTalk] [Bulk] Rohn 25G tower permitting

To: towertalk@contesting.com
Subject: Re: [TowerTalk] [Bulk] Rohn 25G tower permitting
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Wed, 04 Feb 2015 09:46:35 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 2/3/2015 10:56 PM, Brian Carling wrote:

If the 25G is short enough to only need one set of guys, then it will work fine with a "dirt base". ROHN used to sell them. The only requirement for a 50 - 60' 25G even with a big tribander is the soil must be firm enough to keep the base from sinking, or moving sideways.

The base of a guyed tower need only to stabilize the tower, keep it from sinking, or moving sideways.

73

Roger (K8RI)

Thank you Jack,

It is similar to where I was heading, but I am planing to use one set of guy 
wires and a slightly smaller base. If you have guy wires the size of the base 
is not that critical.

I have someone working with me now on the engineering and drawings based on 
information from the Rohn 25G catalog and the TI 222 document.

Best regards - Brian Carling
AF4K
117 Sterling Pine St.
Sanford, FL 32773

Tel: +USA 321-262-5471




On Jan 30, 2015, at 1:56 AM, Jack Brindle <jackbrindle@me.com> wrote:

Rohn has a section in their catalog for unguided towers which includes Rohn 25. They call for something 
like 2.5’ x 2.5’ x 4’ of concrete for the base. I’m not sure I really want to 
be up 35 feet on that, but it has been in their literature for as long as I can remember. I am sure many 
folks have built one of these, and would love to hear opinions on ways to make it safe. I suspect this is 
what the original poster was referring to. Not all of us can have tall towers - sometimes 35 feet will have 
to do, and extensive guy systems can be problematic on small city lots. So, the question really is how do 
we put this stuff up and make it safe? Is this where you were heading, bcarling?

73,

Jack B, W6FB


On Jan 29, 2015, at 8:19 PM, Roger (K8RI) on TT <K8RI-on-TowerTalk@tm.net> 
wrote:

On 1/29/2015 6:57 PM, Grant Saviers wrote:
My 140' Rohn 65 base is 4x4x2 ft. PE engineered.  So 3' of concrete is a bit 
much, check the Rohn catalog.  The most important thing with a base in concrete 
is the legs go through it and into some gravel for drainage.  I've seen many 
legs split by water freezing in them.
Or use a pier pin base with solid lefs. Easy to make and not expensive.

73

Roger (K8RI)

I wouldn't go as far as "3/4 ply and broomsticks" but the loads from 30' won't 
need much of a base for 2000psi soils.  It's all in the catalog.

Grant KZ1W


On 1/29/2015 10:10 AM, Wilson wrote:
I think you are being led around by the short hairs.
How did you decide a 27’ tower needed to be in 3’ of concrete?
For practical purposes there is no bending and no horizontal load at the base of this 
tower, assuming it is guyed, of course, which –25 must be.
You could stand 30’ of 25 on a piece of 3/4” plywood and three broomsticks and 
have a fine installation!
The guywire and anchors are your real design hotspots, so a reasonable estimate 
of overturning moment is necessary.
With it, you figure the worst guyline load and that gives you an anchor 
capacity requirement.
You may have the perfect place for some screw in anchors, or an ideal place to 
display some heavy yard art!
Yes, you’ll have a little horizontal load due to drag on the tower itself, if 
it’s in the clear, so maybe use rebar or pipe instead of the broomsticks.
I have a 2’ square pad and a tilt plate for mine (40’) and it’s overkill.  The 
tilt plate is great for antenna maintenance.

And are you required to tell them all about the antennae to be installed?
The less you tell them, the better, since you’ll be changing eventually anyway.

WL
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

--

73

Roger (K8RI)


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk


--

73

Roger (K8RI)


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
<Prev in Thread] Current Thread [Next in Thread>