I know of 2 places where there are powerlines that run high over highways, and have something peculiar on them. One is on Rt.2 in western Mass. and the other is on Rt.84 a little west of the Rt. 684 interchange (not too far east of the Hudson).
On each of the lines there are what appear to be large red, orange, or yellow colored balls of some sort.
We have some theories for thier purpose. One is that they make the lines more visible presumably so planes don’t fly into them. Another is that they either weigh down or have some aerodynamic property to keep the lines from flapping in the wind like the Tacoma Narrows bridge.
Anyone have the definitive word on their purpose? If so please qualify with your credentials or source of information.
I have seen them down near Quantico marine base, as well as up on 95 near the private airport. I was told by a Marine officer that it is to improve visibility for low flying aircraft.
Visibility is one reason for the balls. You’ll also see them in windy areas. Putting a weight on a cable damps its resonant frequencies and makes it less likely to snap in high winds.
My credentials: I work as a field contract administrator for a pipeline construction firm in Canada.
We recently had to pay our contractor to replace two of these warning balls on powerlines that crossed our right of way. In that case, they were used as a marker to warn the company helicopter pilot (he flies the right of way looking for problems) of their presence.
You’ll also see them in the countryside if there’s a lot of cropdusting going on, for the same purpose.
I’d never heard of them being added for extra weight, but it makes sense now that you mention it.
The Bird Kill reason was actually our other possible theory, but I didn’t post it cause I thought it was the least resonable. It appears to be a beneficial side effect.
So basically we think that my 3 original threories, visibility, weighing down, and so birds don’t die all seem to be the effects of the Balls.
Oh, and I should have known that the male powerlines have balls. I wonder how that relates to the Male Plane (Mail Plane) mentioned in The Three Amigos movie. Maybe the Male Planes are the only ones that would avoid the Male Powerlines?
According to the link yojimbo provided, they are not the dampeners.
So we have two separate items being added to line - giant “antipasta twirls” that are hard to notice, and big colored fiberglas balls. The balls may provide some stabilizing effect as an extra weight, but their intention was as visibility aids for pilots. Both additions seem to have the effect of reducing the number of dead birds. Is it possible that the lines move enough in the wind to kill birds who don’t anticipate it? Then the effect is not visibility, but stabilization? That’s my guess.
Them round ball things on powerlines are to keep near-sighted pilots such as myself from snagging our little airplanes in the wires on either departure or landing.
They may have some other uses, as well, but from my perspective that’s the main one.
The thing is, I seldom see power lines with balls on them other than when they cross a river. I used to think that they were floats to ease recovery in case the line went down. Now, I imagine that aircraft often follow rivers, but still, I seldom see power lines with balls on them other than when they cross a river.
Just to add my $0.02 - power lines are pretty much impossible to see from above. In a small plane, it’s amazing to me that I can be looking at power lines with the balls, and I know there are lines there, but I can’t see them.
All the power line balls I’ve seen are near where you would expect aircraft to be.
I suspect that the river connection is because most valleys have rivers running through them. Power lines usually stay more or less horizontal, so they’re higher above the ground when crossing valleys, so they’re in navigable airspace.
Another reason they might be near rivers and other areas of water is that this is were you would get swans and other large water birds trying to land and take-off on/off the water.
