The recent post about hex nails revealed a lot of opinions concerning our practice of putting nails in utility poles. And they're all pretty much sound opinions.
My utility company clients all know that folks drive nails in their poles. While they could actually probably care less about 95% of them, their "policy" requires them to frown on the practice. The major issue is introducing moisture into the wood or actual damage. Their second issue, believe it or not, is liability. Their employees have actually injured themselves on some of the garbage that us dawdling citizens have mindlessly nailed, stapled, glued and wrapped on and around the poor old local power pole. There was even a claim that a cardboard "garage sale" sign had impeded proper sight of the intersection from a vehicle and was instrumental in an accident...and after all, it WAS the power company's pole...
Between these two issues, I leave them alone. A 60d nail IS large enough to cause some issues in a smaller (Class 5) diameter pole...especially if it's from 1947 and dry rotted. A RR spike is even worse. I have been known to smack a short (1 1/4") PK and a washer in a pole when there was simply nothing else out there. A small nail in a sound pole isn't going to do much damage...But I'd like to share with you all some thoughts about using nails in poles, and it has nothing to do with the power company's wishes or policies.
Poles are a structural member of a very dynamic system, they are NOT fixed or rigid. When they DON'T move or give enough, they snap. While a lower voltage distribution line that just has a couple of conductors attached at the pole is not under very much tension, a pole with a cross-arm at the top can be under a lot of torque. Uneven tension at installation, strong wind shear and eventually maintenance causes these poles to torque (twist) in their hole. I have seen them twist enough to pull the staples off their #10 ground wire that is stapled down the side to the ground rod. That is radial movement of 6 or 8 inches. Harmonic oscillation of 600' of conductor in the wind can cause a lot of movement.
Cyclic wet and dry soil conditions in conjunction with either wind loaded or simple system weight compression of the entire line can 'hammer' a pole deeper in the ground over a period of time. Now granted it is usually considered insignificant to the power company...tell that to a fella that can't get his notes to fit a 15 year old level loop by 0.05'. Tension from contraction has even been known to "lift" a pole if the poles on either side span are significantly higher.
So the next time you want to set a reference for a corner or set a BM, you might not worry so much about whether the power company wants you to set a nail in their pole....you might consider whether or not YOU want to set one there.
There's usually better places. Use your imagination..
Now, that's the difference between someone who knows what they're talking about and the rest of us who just think we know a little somethin'.
paden cash, post: 366106, member: 20 wrote: The recent post about hex nails revealed a lot of opinions concerning our practice of putting nails in utility poles. And they're all pretty much sound opinions.
My utility company clients all know that folks drive nails in their poles. While they could actually probably care less about 95% of them, their "policy" requires them to frown on the practice. The major issue is introducing moisture into the wood or actual damage. Their second issue, believe it or not, is liability. Their employees have actually injured themselves on some of the garbage that us dawdling citizens have mindlessly nailed, stapled, glued and wrapped on and around the poor old local power pole. There was even a claim that a cardboard "garage sale" sign had impeded proper sight of the intersection from a vehicle and was instrumental in an accident...and after all, it WAS the power company's pole...
Between these two issues, I leave them alone. A 60d nail IS large enough to cause some issues in a smaller (Class 5) diameter pole...especially if it's from 1947 and dry rotted. A RR spike is even worse. I have been known to smack a short (1 1/4") PK and a washer in a pole when there was simply nothing else out there. A small nail in a sound pole isn't going to do much damage...But I'd like to share with you all some thoughts about using nails in poles, and it has nothing to do with the power company's wishes or policies.
Poles are a structural member of a very dynamic system, they are NOT fixed or rigid. When they DON'T move or give enough, they snap. While a lower voltage distribution line that just has a couple of conductors attached at the pole is not under very much tension, a pole with a cross-arm at the top can be under a lot of torque. Uneven tension at installation, strong wind shear and eventually maintenance causes these poles to torque (twist) in their hole. I have seen them twist enough to pull the staples off their #10 ground wire that is stapled down the side to the ground rod. That is radial movement of 6 or 8 inches. Harmonic oscillation of 600' of conductor in the wind can cause a lot of movement.
Cyclic wet and dry soil conditions in conjunction with either wind loaded or simple system weight compression of the entire line can 'hammer' a pole deeper in the ground over a period of time. Now granted it is usually considered insignificant to the power company...tell that to a fella that can't get his notes to fit a 15 year old level loop by 0.05'. Tension from contraction has even been known to "lift" a pole if the poles on either side span are significantly higher.
So the next time you want to set a reference for a corner or set a BM, you might not worry so much about whether the power company wants you to set a nail in their pole....you might consider whether or not YOU want to set one there.
There's usually better places. Use your imagination..
Never knew that about the instability of power poles; thank you for the heads up. [sarcasm]That is why I use fire hydrants for bench marks.[/sarcasm]
Ken
I do not know if I can make the link below work or not, but it is a video of several large power poles that were downed in a storm we had a short while back.
[MEDIA=facebook]1170342642998233[/MEDIA]
kkw_archer, post: 366184, member: 5453 wrote: I do not know if I can make the link below work or not, but it is a video of several large power poles that were downed in a storm we had a short while back.
Nice video. A lot of people would be surprised to hear the design wind load on wood transmission lines is only around 90 mph. Around here the wood is giving way to direct bury galv. steel modular poles. They crumple up too in a tornado.
These went down reportedly due to straight line winds, but I didn't hear any reported speeds. I sure would have like to have seen them going down (from above), I bet it was a sight.
Yeah, I kind of found out about that 25 years ago. I was a young chief running my control and level loop getting ready to do some layout for an addition of a existing industrial park. I set a RR spike for a TBM in the base of a power pole that was scheduled to be removed. When the Electric Co op finally took the pole down, they cut about a 3' section of it which included the spike and brought it to our office. They set it next to my desk for decoration. They thought they were being funny....
