[TowerTalk] Guy anchors in shallow soil

[john at kk9a.com]

How did you dig your tower base?  Often times it is easy to dig a hole
with a small backhoe and use a standard concrete anchor.

John KK9A

To:	 "towertalk at contesting.com" <towertalk at contesting.com>
Subject:	 [TowerTalk] Guy anchors in shallow soil
From:	 Linux Mercedes <linuxmercedes at gmail.com>
Date:	 Sat, 30 Aug 2014 17:27:44 -0500

So I have been trying to put up a 50' 25G tower for a little while now. I
bought some 6'x8" screw anchors thinking they'd go into the clay soil
pretty easily, and they do...for about two feet. Then they hit rock; I am
pretty sure it's bedrock or something similar from talking to my
neighbors. Obviously that's hardly enough earth for a screw anchor to hold
on to.

What are my options here? Looking at Rohn's drawings, I am entirely sure
that going down 4' for a concrete base is out of the question. I am
currently thinking I'll bust a hole about 8" around down maybe 3', dig an
angled trench for the bar of the screw anchor, and set it in the hole with
a bag or two of concrete. Hand digging that hole doesn't sound fun,
though.

For what it's worth, I'm in central Missouri.

Thanks!
--Nathan