How would a pier pin pull out? There is little lateral force and
absolutely no upward force on the pin.
John KK9A
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] Rohn BPC25G
From: "D. Scott MacKenzie"
Reply-to: kb0fhp@comcast.net
Date: Fri, 18 May 2007 20:19:35 -0400
Thank you - I appreciate it.
The fender washers and nuts would be located in the concrete - they serve as
resistance to prevent pulling the pin out.
Looks like I am good to go then - I can start getting the foundation and
stuff ready for the tower....Thanks!
Scott
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of K7LXC@aol.com
Sent: Thursday, May 17, 2007 10:13 AM
To: towertalk@contesting.com; kb0fhp@comcast.net
Subject: Re: [TowerTalk] Rohn BPC25G
In a message dated 5/13/2007 11:32:34 A.M. Pacific Daylight Time, towertal
k-request@contesting.com writes:
> I have the Rohn BPC25G, which is the concrete base plate for 25G. It
requires a single pier pin, but there are two holes - one in the center,
and
one at the edge of the plate. I realize I use the center pin, but what
purpose does the other hole serve?
Hmm, I don't know. I don't recall seeing a second hole in the base
plate. Doesn't sound like anything to worry about.
> The pier pin, Rohn 3/4x12PP, is also a smooth pin, without any other
features. There is nothing to hold it in the concrete.
Except the concrete or some epoxy.
> Would 3/4" threaded rod (material is similar to the pier pin), with
large
fender washers also serve as a better pin - at least there would be
something to hold it in the concrete. There is nothing that I have found
in
the Rohn catalog that would provide me guidance.
Sure, I've done that before. There really aren't any lateral forces on
the pier pin so the all-thread will be plenty. What are the fender washers
for? Don't put them between the concrete and the baseplate - the baseplate
should sit right on the top of the concrete.
Be real careful with your temporary guying as you put it up and you'll
be good to go. I personally don't see any value for using a pier pin with
25G
- the forces are pretty small. A pier pin is really for big towers where
using it will help to equalize the compressive forces on the legs -
something you
don't necessarily get when you bury the bottom section in concrete.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188
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