[TowerTalk] Foundation Failure

[Tom Frenaye]

At 11:36 AM 10/12/2006, Michael Baker wrote:
>        When have you EVER seen a tower foundation FAIL? I mean deteriorate
>to the point it wouldn't work as a tower base anymore.  

I had a tower base "fail" about 20 years ago.   It may depend on what people think "fail" means.

During Hurricane Gloria in 1985, I had a 4-6" tree limb fall on a lower guy anchor of a 90' Rohn 45 tower guyed at 30/60/90' and with 20/15/10 monobanders and a couple of inverted Vees on it..   

The tree limb caused enough down pressure to actually bend one leg of the tower - it bent outward several inches (about 4' from the ground).    That in turn caused a guy anchor on the other side to pull out of the ground (a screw in anchor that should have been in concrete).   So the tower started to sway and then titled about 20 degrees onto some nearby trees.   My wife and I grabbed the loose anchor and tied it around a nearby tree and I think that kept things from completely failing.    

The next day after inspecting the damage I noticed the ground was broken about two feet out from the tower, almost all around the base.   What had apparently happened is that as the tower leaned over into the trees, it had enough leverage to move the entire base within the (somewhat sandy) soil.  To me that was a foundation failure.   The concrete didn't deteriorate though.

I was able to fix the tower - I put in a concrete anchor, then had a professional tower crew come and untangle the tower from the trees, get it back vertical, and I think the base moved "back" to where it started.   I also had a welder come in a few weeks later and remove the bent portion of the tower leg and put in a replacement.    

I moved a few years later so the base was discarded.  That tower section is still in use at the present QTH.

          -- Tom


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