[TowerTalk] GAS604 screw anchor...

[K7LXC@aol.com]

In a message dated 04/20/2000 7:04:02 AM Pacific Daylight Time, 
rrossi@btv.ibm.com writes:

> My Rohn catalog does not give any data for the GAS604 screw anchor. All I 
can 
>  find anywhere is with the item description "screw anchor 2500 pound". I 
would 
>  guess that this is the holding strength in "normal undisturbed cohesive 
soil". 
>  Is there an engineering document from Rohn (or elsewhere) that someone 
could 
>  e-mail or fax me an image of??
  
       The AB Chance Company publishes the "Encyclopedia of Anchoring" 
(573-682-5521 and it's free) which shows there are eight different soil 
classifications with "Probe values" in in-lbs. But short of doing a soil 
test, it's hard to say what your conditions would be.

      The Chance 'encyclopedia' is interesting reading but of limited 
practical value.

      The main concern for the Rohn screw-in anchors is that the 3/16" EHS is 
rated at 4000 pound breaking strength and the anchor is only rated at 2500 
pounds. Obviously the anchor is going to pull long before the guywire breaks. 
Screw-in anchor creep is another real problem. Bottom line? Install regular 
concrete anchors instead. IMO screw-in anchors are for TEMPORARY use only. 
      
       To answer your question about the existence of Rohn documentation, 
I've never seen any and I doubt that it's available. 

Cheers,   Steve   K7LXC
Tower Tech 

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