Power/ Utility Pole
Power/ Utility Pole
(OP)
I am in the process of detailing some power transmission poles that bring power from the road into a substation yard for a new facility. My question is, does the electrical contrator usually field drill the holes in the pole for the connections of insulators and other hardware?






RE: Power/ Utility Pole
RE: Power/ Utility Pole
RE: Power/ Utility Pole
These are dodecagonal or 12-sided steel poles anywhere from 45' to 60' tall.
RE: Power/ Utility Pole
RE: Power/ Utility Pole
RE: Power/ Utility Pole
Often, steel structures will be specified with flanges that have a series of pre-drilled holes for various hardware spacings. Utilities standards departments will have established specifications to suit their construction types. The crews will pick the closest holes that fit conductor elevation and spacings.
RE: Power/ Utility Pole
RE: Power/ Utility Pole
RE: Power/ Utility Pole
see my first post...I am detailing and having the poles fabricated...I am the manufacturer.
RE: Power/ Utility Pole
What would be the big deal with using thru-bolted hardware on a steel pole? What are the concerns here?
RE: Power/ Utility Pole
RE: Power/ Utility Pole
Keith Cress
kcress - http://www.flaminsystems.com
RE: Power/ Utility Pole
As the design engineer of the poles I can assure that drilling a several small holes will be of no structural consequence whatsoever. Even holes drilled in very heavily loaded building beams/frames are for the most part totally ignored in the design process so long as they are not drilled in an area of high stress or are unusually large (something other than bolt holes).
RE: Power/ Utility Pole
Keith Cress
kcress - http://www.flaminsystems.com
RE: Power/ Utility Pole
Sorry, I wasn't trying to get indignent on you, but it sure as hell sounded that way didn't it!!!
RE: Power/ Utility Pole
You might want to include threaded holes for ground connectors if any equipment needs grounding or if the poles need connected to a separate grounding electrode.
RE: Power/ Utility Pole
Thank you.
Makes damn good sense.
First good answer.
My main concern was drilling the galvanized pole afterwards and having to make repairs.
The biggest problem I have here is I am a Structural Engr who is designing and detailing the poles (working directly for the owner....everything done in house).
Laying out power transmission lines is not my thing. We have required pole heights, line elevations and hardware details from our Electrical consultant, but i am not comfortable with laying out the hardware locations on the detail drawings. I have completed it, but still dont have much confidence in it. My thinking was that if i left the poles blank I could have the contractor work directly with the Electrical Engr consultant and be sure the hardware locations were correct.
RE: Power/ Utility Pole
RE: Power/ Utility Pole
RE: Power/ Utility Pole
"Practice within your expertise"
So, designing a pole for line tension loads, ice, wind etc. is not the expertise of a Structural Engineer? Should I consult a "Pole Engineer". Can you do it for me?. I am well within my expertise here and I by no means expect the fabricator to do anything but EXACTLY what I put on the drawing. If my electrical "expert" wasn't a jagoff, I wouldn't have to worry about it. I'd detail the pole showing attachemnt points and have him review it.
RE: Power/ Utility Pole
RE: Power/ Utility Pole
"As an engineer, we all shall participate in none but honest enterprises. When needed, our skills and knowledge shall be given without reservation for the public good. In the performance of duty and fidelity to our profession,we shall give the utmost."
I am not questioning your expertise! I was just suggesting for you to exercise what you are an expert at?..........
RE: Power/ Utility Pole
I've never seen it (the transmission design) left up to the installer, or the pole manufacturer.
Field drilling is common if something like a crossarm for a distribution circuit is attached to the same pole. Even then there should be a design standard, and a work package from the estimator/designer.
What is the transmission voltage for this line?
RE: Power/ Utility Pole
Do you mean field drilled at some random point through the pole? Now, I'm no structural engineer, but my understanding is that these things are hollow. Just running a bolt through the middle and placing it under tension (dead ending a conductor, for example) and the pole could squash like a beer can.
In my experience, attachment points for significant loads have to be properly reinforced (the odd street light is probably OK). At least that's what my structural people have told me.
RE: Power/ Utility Pole
ASCE 48-05 is currently under revision with some cautions regarding these issues.