View Full Version : Birds On A Wire

01-14-2000, 01:12 PM
If the bird has both feet on one wire, he is essentially just a bump on the wire. If the bird puts one foot on one wire and the other foot on another wire, he is a goner. (Difference of potential)

01-14-2000, 01:21 PM
The birds haven't been to college and haven't taken freshman physics, so they don't know what's supposed to happen to them. It's like the coyote running off the cliff -- he doesn't fall until he looks down.

"To do her justice, I can't see that she could have found anything nastier to say if she'd thought it out with both hands for a fortnight."
Dorothy L. Sayers
Busman's Honeymoon

01-14-2000, 03:14 PM
CrystalGuy, but isn't the bird at different potential when the bird approaches the wire to land? What a bug zapper it should make!

01-14-2000, 05:32 PM
Originally posted by Jinx:
CrystalGuy, but isn't the bird at different potential when the bird approaches the wire to land? What a bug zapper it should make!

If that was the case, no bird would survive landing on a wire. In order for current to flow, a circuit must be closed. A bird with one foot on one wire and one foot on another wire very effectively closes the circuit and current will then flow in a big way.

01-14-2000, 05:38 PM
Because they can. They just do. But crystal guy is 100% right. That's why you have to go to KFC to get fried pigeon. :D

Talk to me, baby!

01-15-2000, 12:14 AM
I understand that high voltage lines are not insulated, yet birds can fly up and perch on these live wires. I was told that since a flying bird is not grounded, there is no electrical shock to the bird.

But, the bird IS at a different potential than the electric wire, so one would expect an electrical spark to arc to the bird. Yes?

Mr Thin Skin
01-15-2000, 12:32 AM
Maybe a teeny one for lil' birdies. For big birds, such as helicopters, there is a substantial arc. I saw a show a few years back about a company that performed high-tension line maintenance via helicoper. It seemed that ground-based maintenance was violently expensive, and using helicopters turned out to be relatively cheap. In the show I saw, they were replacing these wire separators. The helicopter had a little platform below the runners, some worker, dresses entirely in conductive clothing (Faraday cage type thing) reached out and grounded the helicopter to the lines. A one-two foot arc would form between the grounder and the power lines. After that, work proceded quickly.

So it has to do with the capacitance of the boid.

Mr Thin Skin
01-15-2000, 12:34 AM

I saw a boid at toidy toid and toid

01-15-2000, 12:52 AM
When I was very young, I saw some men working on an electrical high-voltage tower near my house once wearing suits as you described. I thought I was seeing "spacemen", but never spoke about it. I figured there HAD to be some logical explanation.