[TowerTalk] hinge/base plate

[K7LXC at aol.com]

In a message dated 4/25/2007 8:25:21 A.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  here is what i have and what i am wanting to  do,

>  as it "stands" now i have a rohn 20 tower at 40ft when i  installed this 
tower about 10 years ago i didnt use a base plate so she is  in 3x3x4 or 
close to that, in concrete since then i have become a ham and  noticed the 
need for more tower work, what i am wondering is unstack the  one cut it 
flush with the concrete make a hinge plate and bold it down to  the existing 
concrete using heavy duty lag bolts? will this hold? we do  not have alot of 
wind or ice here. i do not have this one guided off no  room for it so 
getting down to it will it hold with out guy wires at a  hight of 40ft, 
bolted down with lag bolts that i will have to drill into  the existing 
concrete?


    If you're in Prentiss County, it's a 70 MPH  windspeed zone. Freestanding 
25G is rated 1.5 square feet at that windspeed.  Rohn specs call for a base 
size of 4x4x4 using 2.4 cubic yards of  concrete so your base is a little 
undersized. Fatally? Probably not. 
 
    So your plan is to take it all down, put in a  hinged base and then 
reassemble everything? Personally I'd be more comfortable  having a section in 
concrete instead of the hinged base so I'd leave it  the way it is. Lots less work 
too. 
 
    You can drill the concrete and put in anchor  bolts with epoxy and it'll 
hold just fine if that's the way you want to go.  

Cheers,
Steve      K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188








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