I used 5' anchors with 6" augers (maybe they are 8"--can't remember) that they
use for power pole guys on my tower. My tower is 100' of 25G with 3 guys of
1/4" EHS. I have about 17' of wind load on top. Winds have gusted to about
60mph or so since I put it up about 6 years ago or so. My soil was
undisturbed. I screwed the anchors in with a long pipe at an angle about what
the middle guy is. The soil is about 4" to 6" of "dark dirt" on top of a
yellowish fine sand, that gets yellower and denser as it gets deeper. The
nearest standing water is a 1/2 mile away--so I am really dry. I have about 10
yards of concrete at the tower base. I have used one of these anchors (not
guyed to the tower!) for a winch anchor to pull stumps and only screwed it is a
few feet. The power line guys told me they tried to pull out a 5' shaft 12"
auger anchor from similar soil with a D6 cat and could not. They also said
they never have had to replace an auger anchor when a car hits a guy wire--the
cable is pulled--bolts and washers--right through a pole. They just drill
another hole. If you have firm, solid soil that will remain that way, you can
use screw-in anchors. If you have loam with some clay that holds water and get
mushy when it rains--they could pull out as the earlier post showed. Most of
the towers in my area use augers, including some 200' commercial towers. Check
with the soil conservation people in your county government to see what you
have and then go from there. Just because it will work across the road doesn't
mean it will work on your side.
Rudy Marcelletti, K8SWD
|