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
************************************** See what's free at http://www.aol.com.
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