[TowerTalk] concrete bases for freestanding towers

[Adam Shirley WJ4X]

My 40 HDBX has closer to 6 yards under it. It's a block 6.5 square, 6 ft
deep. The old Rohn drawings specified a 4' deep hole. I also have a yard
of gravel in the bottom of the hole to prevent ice lensing. (Which at 6
ft deep shouldn't ever happen here in 4 land! HIHI)

I take the Walt Disney mantra of engineering, take what you know, design
it to your best, then "plus" it to make it better.


73!
 -Adam




On 5/13/2011 8:18 AM, WA8JXM wrote:
> Many years ago I had a 64' freestanding tower with a 3el triband beam (TA-33) on it.  The base was only 2 cu yards of concrete.  As far as I remember, that was all the manufacturer (Heights) recommended at the time.
> 
> Now when I look at anyone's recommendations, the base requirements are much larger.  Rohn (and others) recommends 3 cu yards even for a 40' BX tower.    I had used only 1 cu yard for a freestanding 40' tower.
> 
> Is my memory faulty, or have the recommended bases grown over the years?  Were the old recommendations inadequate, or has everyone grown super conservative over the years?   "If one yard is adequate, three will be better, so let's use five yards"???
> 
> As one ham commented on the air yesterday, the only failures he has ever heard of were in the tower itself, not the base falling over.  
> 
> Ken 
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