On 4/15/20 4:23 AM, Rob Atkinson wrote:
Lots of big towers and telephone poles are safely anchored by screwing something
into the ground. I'd venture that very, very few wooden poles, even those giant
ones, have any concrete involved at >all, and they have fairly large side
loads, both static, and wind driven, from the wires and line equipment.
It's ridiculous to draw an equivalence between a lattice tower
properly resting on a pier and pin with a telephone pole, that is
solid wood, and in the ground 10 feet in a tight hole made with an
auger. Wood as a material behaves in a completely different manner
under stress. Phone pole guying is usually done to counter the pull
of power cables at the end of a line or when there's a change in
direction. Otherwise wood poles are usually unguyed. A tower on a
pin has to be guyed just to remain vertical. A wood pole won't
collapse from being sunk into the ground. A tower will unless it is a
short stub
I was thinking more of the anchors for the guys and at least for ones
I've seen recently, they're under quite a bit of tension (at a corner in
the line, so the line tension is asymmetric.
Yes, the stiffness of the wooden pole in a hole in the ground helps, but
under constant load (which is the case in most phone poles) they'll lean.
I've not measured the tension on a phone pole guy, but there's not a lot
of "give" in the guy wire when you lean on it, so the load on that screw
in anchor is pretty high.
But this goes back to the original comments - a screw in anchor is an
engineered solution, not a wheelbarrow, shovel, and drawing solution.
Horses for courses.
73
Rob
K5UJ
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