Balls on transmission lines
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LawnGuyLandSparky
Senior Member
Just to put this mystery to rest...
These:
Are what's INSIDE these:
These:
Are what's INSIDE these:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Maybe the ground wires aren't strong enough for the balls, but they're on top because lightning usually comes from above.
Balls on transmission lines
There is a set of these orange balls on some transmission lines next to the Lake of the Ozarks Bagnell Dam. My daughter, being curious about everything, asked what the orange balls were for as we drove across the dam. Since they were running over a long span of water, i said they were floats that would keep the power lines from sinking in a severe flood. Later, when she was a little older, she began to question whether a flood could reach hundreds of feet over the top of the dam, and also whether Aardvark milk was trucked around in those tank cars on trains, which is another thing I told her at 6 years old. I have maintained steadfastly that they are floats.
--Lawrence
There is a set of these orange balls on some transmission lines next to the Lake of the Ozarks Bagnell Dam. My daughter, being curious about everything, asked what the orange balls were for as we drove across the dam. Since they were running over a long span of water, i said they were floats that would keep the power lines from sinking in a severe flood. Later, when she was a little older, she began to question whether a flood could reach hundreds of feet over the top of the dam, and also whether Aardvark milk was trucked around in those tank cars on trains, which is another thing I told her at 6 years old. I have maintained steadfastly that they are floats.
--Lawrence
My dad also tried to convince me they were floats. He said that if the line broke over the river the balls would float and the current would carry the ball to river bank. This way they didn't need to get their boats out to make the repair. I can't wait to try this on my kids!
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
You guys are so mean! 
I Design Transmission Lines
I Design Transmission Lines
The people who say they are for visibility are right. Usually they are for aircraft, but sometimes also for birds. (Fish and wildlife people make engineers do nutty things.)
For lake crossings, they may be also for warning sail-boaters.
They can be attached to the overhead ground wires, or the current-carrying phase conductors, or both. All depends on who is making us engineers do nutty things.
They are NOT for vibration. Other devices control vibration (stockbridge dampers, impact dampers, airflow spoilers, detuning pendulums, etc.
They are NOT filled with any kind of gas.
I Design Transmission Lines
The people who say they are for visibility are right. Usually they are for aircraft, but sometimes also for birds. (Fish and wildlife people make engineers do nutty things.)
For lake crossings, they may be also for warning sail-boaters.
They can be attached to the overhead ground wires, or the current-carrying phase conductors, or both. All depends on who is making us engineers do nutty things.
They are NOT for vibration. Other devices control vibration (stockbridge dampers, impact dampers, airflow spoilers, detuning pendulums, etc.
They are NOT filled with any kind of gas.
broadgage
Senior Member
- Location
- London, England
Agreed, here in the UK orange or red plastic balls are used to make the line more visible to airplanes and to wildlife.
They are not filled by hydrogen or helium, the lifting effect that could be obtained would be minute and not worth the expense and trouble. To be pedantic, they are filled with air at atmospheric pressure.
The balls look like floats, because they ARE floats, mass produced for toilet cisterns and for fishing nets.
I recently found 2 that had fallen from a line, they were standard toilet cistern floats.
The intention is not however to float a downed line, they are not big enough anyway.
Vibration dampers are similar to those illustraed some posts back, consist of two weights fixed to short rods, the whole assembly being fixed paralel to the line.
Zorak
Member
Maybe someone already mentioned this, but the only places that I have ever seen the balls on transmission lines are when they cross highways. I have not seem them on all lines that cross highways, but that is where I have seen them. Go a section upstream or downstream and you do not see them.
But highways are supposed to have straight lengths to facilitate aircraft landing in emergencies. Most likely, you are not going to try to land in some uneven pasture (though Kansas is pretty flat) but put down on a level smooth (applies to all states but Missouri) highway , thus I think in my neck of the woods (Kansas), they are there to help pilots see the transversing transmission lines when having to make emergency landings.
That's my guess.
Z
But highways are supposed to have straight lengths to facilitate aircraft landing in emergencies. Most likely, you are not going to try to land in some uneven pasture (though Kansas is pretty flat) but put down on a level smooth (applies to all states but Missouri) highway , thus I think in my neck of the woods (Kansas), they are there to help pilots see the transversing transmission lines when having to make emergency landings.
That's my guess.
Z
K8MHZ
Senior Member
- Occupation
- Electrician
I think it's to reduce corona effect and to reduce the likelihood of an ungrounded conductor energizing the grounded conductor in the event of a line break.
Lightning comes from both ends and meets in the middle. Watch the high speed photos of the stepped leaders coming from both the clouds and the most prominent object in the area. The potential is from a charge center in a cloud to a charge center in the earth (for cloud / ground strikes) and the incipiently ionized air really doesn't care which end is which.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Maybe, but it would still be weird to see the ground wires strung between the lines and the dirt.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Besides visibility, they are used in places where the lines can not be separated enough to prevent wind slapping, which is to say they keep the cables from touching in high wind, we have then in a few places where the pole trees are not broad enough to keep the wire apart so they use these balls to prevent the wire from being driven together by the wind.
mivey
Senior Member
Hmmm. Not buying it. Does not meet any spec I've ever seen.
add: Not saying you have not seen it. Just can't believe that was the reason for it.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
And I agree, but we do have some used to stop wire slapping, at least this is what I was told there for by the POCO, but heres a link to a manufacture of these BALLS, and a good resource of some info backing the visibility requirements by FAA. nothing on the bird requirements, but there is allot of info on the net for that one, just Google "balls on power lines" and it will pull up all kinds of info
mivey
Senior Member
I don't recall any specs for the ones we use that say they can be used for keeping the lines from slapping together. There are aluminum, fiberglass and ABS balls. For obvious reasons the aluminum would be excluded. The fiberglass would not hold up to much smacking around as they are not as durable as the ABS ones.
As for the ABS balls, the ones I have seen are not spec'd to allow them to be slapping together in a high wind. The correct way to avoid this problem is to properly design the line to allow for blow-out conditions, even when there is a slack span.
K8MHZ
Senior Member
- Occupation
- Electrician
Sadly, some of these weren't seen by a USCG helicopter pilot.
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