ECN Forum Forums General Topics of the Trade General Discussion Area Recommended hole depth for high poles???

Does anyone know the recommended hole depth for different size poles? I believe the recommended depth for a 30 ft. pole is 5 ft. in the ground, but other sizes I'm not sure. Thanks for the input... Steve

That depends on the soil conditions and how much tension in on the wires.

Your local Power Company probably knows best.

when i last looked at my duke power notes from several years ago, they required any temporary power pole (saw service) to be 4 ft in the ground. that was when i bought a post-hole digger. for a 30 ft pole i'd call 'em to be sure.

Lineman’s Handbook - §11

25 ft pole 5.0 ft in soil / 3.5 ft in rock
30 ft pole 5.5 ft in soil / 3.5 ft in rock
35 ft pole 6.0 ft in soil / 4.0 ft in rock
40 ft pole 6.0 ft in soil / 4.0 ft in rock
45 ft pole 6.5 ft in soil / 4.5 ft in rock
50 ft pole 7.0 ft in soil / 4.5 ft in rock
55 ft pole 7.5 ft in soil / 5.0 ft in rock
60 ft pole 8.0 ft in soil / 5.0 ft in rock




[This message has been edited by Bjarney (edited 08-28-2003).]

Bjarney,
Are poles in the US set into concrete(cement) at the base of the pole?.
What is more common wood or concrete poles?
What sort of wood is used (where wood is used), to fabricate poles and cross-arms in the US?.

[This message has been edited by Trumpy (edited 08-29-2003).]

Not seen concrete used with wood poles for distribution circuits, which are just about universal [at least in the western US] and planted in tamped soil. Concrete might be used in rock. Transmission and subtransmission <20 years are tubular steel—a good part of them are pre-rusted “Corten” finish—and also “ANSI 71 Sky Grey.” A lot of lattice towers still in service 69-525kV. Concrete bases for tangent towers, but some directly buried tubulat steel where strain is limited.

One common wood for poles is pressure-treated Western Red Cedar, and pressure-treated Douglas Fir for crossarms—although wood crossarms are out of vogue. Fiberglass rod is used for some insulator supports—some galvanized steel—and a lot of circuits are fairly-tight triangular construction—vertical in others. Utilities [and regions within large utilities] seem to all have variations.

The general rule of thumb is...10% of the height of the pole..plus 2 feet.

That is our companies general requirements..but of course soil conditions might dictate something else.