[TowerTalk] Only 2 Pier Pins on Rohn 25 Baseplate?

[Bob Smith]

Hi Jon,

The one or two pier pin system is adaquate for most towers.  I just completed
installation of two 80' Rohn 25 towers bracketed at 50' on the side 
of a water tank
and made some 'bases' that were installed in the concrete foundation 
that used 4@
threaded bolts in the base.  This was a little 'overkill' but the 
towers were designed to
have a single 24dbi PacWirelesss grid antenna, 
http://www.pacwireless.com/products/DC24.shtml,
installed at the top and the companydidn't want to have guys from the 
tower.   So, with a
4'x4'x5' footing, the 'manufactured' rohn bases with extensions of 4' 
long, the heavy duty eve
bracket (36" from the tank) mounted to an 8" pieces of stainless 
angle ( 7' long) the towers
are bracketed at 50' and free stand from 50'-80'  with the antenna 
(1sqft wind load) at the top.
I've got some pictures of the bases if you would like to see 
them,   let me know,

bob
NA6T

Robert Smith Consulting
"Wireless Installations -- Government, Businesses & ISP's"
F.C.C. Licensed-Commercial & Amateur Services
A.R.S NA6T
ARRL Life Member
1-707-964-4931 w/answering machine
Fort Bragg, California   95437

"On The Air-Conditioned Mendocino Coast, In REAL Northern California"
No trees were destroyed in the sending of this message.
However, a large number of electrons were terribly inconvenienced.



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Message: 8
Date: Thu, 25 May 2006 01:27:48 -0700
From: "jknodel M Knodel" <jknodel at msn.com>
Subject: [TowerTalk] Only 2 Pier Pins on Rohn 25 Baseplate?
To: towertalk at contesting.com
Message-ID: <BAY104-F345DE7B1A256E53A076400A8990 at phx.gbl>
Content-Type: text/plain; format=flowed

Hello all,

I am back again with another question.  Thank you to all who have replied
and helped answer previous questions that I have posted.

I noticed that the standard (not hinged) concrete base plate for Rohn 25
only has holes for 2 pier pins.  Is is advisable to drill an additional hole
or two in the base plate and install additional pin(s)?  It would seem that
this would secure the plate to the concrete foundation more securely.

Or, is the plate designed for only 2 pins so that the tower base can
slightly move with the wind forces, such as the commercial towers do with a
single point bearing connection?

Thanks for any help.

73,

Jon, N7XW




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Message: 9
Date: Thu, 25 May 2006 04:28:48 -0500
From: "bob" <wf3h at vsswireless.net>
Subject: Re: [TowerTalk] Only 2 Pier Pins on Rohn 25 Baseplate?
To: "jknodel M Knodel" <jknodel at msn.com>, <towertalk at contesting.com>
Message-ID: <01c101c67fdd$a1783ef0$6401a8c0 at bob>
Content-Type: text/plain; format="flowed"; charset="iso-8859-1";
         reply-type="original"

I only had 1 pier pin. Tower was up for 15 years. It gently rotated slightly
with the wind as it was designed to do. So, no, no additional pier pins are
needed...as K7LXC always says....do what the mfr says and don't do what he
doesnt say

Bob/WF3H

----- Original Message -----
From: "jknodel M Knodel" <jknodel at msn.com>
To: <towertalk at contesting.com>
Sent: Thursday, May 25, 2006 3:27 AM
Subject: [TowerTalk] Only 2 Pier Pins on Rohn 25 Baseplate?


 > Hello all,
 >
 > I am back again with another question.  Thank you to all who have replied
 > and helped answer previous questions that I have posted.
 >
 > I noticed that the standard (not hinged) concrete base plate for Rohn 25
 > only has holes for 2 pier pins.  Is is advisable to drill an additional
 > hole
 > or two in the base plate and install additional pin(s)?  It would seem
 > that
 > this would secure the plate to the concrete foundation more securely.
 >
 > Or, is the plate designed for only 2 pins so that the tower base can
 > slightly move with the wind forces, such as the commercial towers do with
 > a
 > single point bearing connection?
 >
 > Thanks for any help.
 >
 > 73,
 >
 > Jon, N7XW