[TowerTalk] Guy Anchor Corrosion

[Art Greenberg]

Mark Allen of Rohn presented at Hamvention this past weekend on the topic 
of tower safety and maintenance. One of the issues raised in his 
presentation is that of guy anchor corrosion due to soil contact. He 
showed photographs of a large anchor that failed due to corrosion at the 
point where the anchor exited a buried concrete foundation.

I am planning a 70-foot 45G installation. The current Rohn catalog shows 
buried guy anchor foundations for all guyed installations of 45G. In my 
case, the Rohn design calls for an "AB2" guy anchor foundation block, 
which is 4'x6'x1.5' buried in a 4' deep hole, meaning that the top of the 
block will be 2.5' below grade.

I do vaguely recall an older Rohn catalog (if memory serves, it was spiral 
bound and thick as a phone book) that showed guy anchor foundations that 
did prevent soil contact with the guy anchor. Do any of you have one of 
those old catalogs?

I have contacted Mark to see if Rohn can make an older/alternative guy 
anchor foundation design available.

As an aside, catching corrosion before it causes a guy anchor to fail 
would require excavating all the way down to the foundation block. Isn't 
the weight of the soil above the foundation considered in the design of 
the foundation? I wonder if such an excavation is safe.


--
Art Greenberg
WA2LLN
art at artg.tv