[TowerTalk] Power lines, hawks, and fire ignition (slightly off-topic)

Jim Lux jimlux at earthlink.net
Mon Jul 26 14:19:24 EDT 2004


At 10:53 AM 7/20/2004 -0600, Bill VanAlstyne wrote:
>I couldn't help but wonder at this snippet from an AP newswire article in
>this morning's paper regarding how the Santa Clarita wildfire in California
>supposedly started: "[The wildfire] was ignited when a red-tailed hawk flew
>into a power line, was electrocuted and fell, burning, into brush."
>
>I know some of you guys on this list are extremely knowledgeable about the
>basic physics of electromagnetism. Could somebody please explain how a
>single high-tension AC wire can ignite a hawk? (Yuck.) Where does the
>current flow -- I mean, between what and what?
>
>Bill / W5WVO
>_

It's a pretty rare HV line that's a single conductor.

The hawk's wingspan can easily be 4 ft, more than enough to bridge two 
wires on a MV (14-16kV) feeder.  Doesn't look that big when you see them 
flying up in the air, and the wings fold nicely when they are perching at 
lower heights.

OR, the hawk lands on the crossbar of the power pole and bridges between 
grounded pole and hot wire.

For hardcore researchers it's Buteo jamaicensis...




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