[TowerTalk] Rohn BPC25G

[K7LXC at aol.com]

In a message dated 5/13/2007 11:32:34 A.M. Pacific Daylight Time,  towertal
k-request at 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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