What’s on the pole?

October 3, 2006 2:43 PM

Can anyone identify the device on this pole?

These poles are located every couple of miles along the Washington side of the Columbia River between Plymouth and Goldendale. At first I thought they might be some kind of antenna for the agriculture businesses or barges on the river but then I remembered that the Umatilla chemical weapons depot is right across the river and wondered if they might be some kind of chemical detectors. Does anyone know for sure?

posted by Tenuki to Technology (17 answers total)

They look like cell signal transmitters.
posted by rintj at 2:55 PM on October 3, 2006

That's not what cell antennas look like.
posted by Steven C. Den Beste at 3:09 PM on October 3, 2006

Yeah, they usually look like palm trees. /snark
posted by muddgirl at 3:11 PM on October 3, 2006

Actually, cell towers don't usually have toruses on them, they usually have bars. Those things would be useless as cell phone transmitters because cell phone signals are directional, not omnidirectional.

My guess is sirens for warning about a chemical leak. There are similar looking devices used for tornado or tsunami warnings in various areas.
posted by SpecialK at 3:21 PM on October 3, 2006

(BTW, is anyone else miffed by knee-jerk responses to "what is this?" questions? There was one last week that was actually the bolt from a rifle, the first three responses all said it was a router bit even though it obviously had no rotational function nor attachment point...)
posted by SpecialK at 3:22 PM on October 3, 2006

For what it is worth, I've seen notification sirens near the Dugway weapons depot in Utah, and I don't remember them looking quite like that, but they were similar.
posted by Good Brain at 3:37 PM on October 3, 2006

Best answer: Indeed, it's a warning siren. More info here.
posted by jal0021 at 3:42 PM on October 3, 2006

Check out the bottom of this very Web 1.0 page.
posted by knave at 3:48 PM on October 3, 2006

It's my toilet brush.... I've been looking for that!
posted by Doohickie at 3:58 PM on October 3, 2006

Indeed, it's a warning siren. More info here.

Yep, you're right!


posted by ericb at 4:01 PM on October 3, 2006

They are community warning sirens made by Federal Signal in University Park, IL. I used to build them in the early 90's.

You do not want to stand next to these when they go off. They are incredibly loud :)
posted by SteveTheRed at 4:34 PM on October 3, 2006

So the next question: why would a siren look like that?
posted by smackfu at 4:36 PM on October 3, 2006

Best answer: Inside, there are are four horns that sit horizontally in sort of an iron cross shape. The housing protects the horns and associated electronics from the elements. More discs = more dB.

On a side note, I once tested one of these discs inside the factory at my bench, but I forgot the resistor array that we used to attenuate the sound. The bad part was that I lost my hearing for about two hours. The good part was that I couldn't hear my boss chewing my ass. :o)
posted by SteveTheRed at 4:45 PM on October 3, 2006 [2 favorites]

Hmmm.... I think SteveTheRed deserves a "best answer" for building the damn thing under question.
posted by Kraftmatic Adjustable Cheese at 6:40 PM on October 3, 2006

I was thinking exactly what Kraftmatic Adjustable Cheese said.
posted by zek at 6:44 PM on October 3, 2006

I didn't mean my post above to sound as grumpy as it might be read. I should have ended it with a ! to indicate how impressed I am by this thread.
posted by Kraftmatic Adjustable Cheese at 7:04 PM on October 3, 2006

Not answering the question, just clarifying some misinformation on cell towers from above. Cell towers are usually, but not always directional. There are plenty of omnidirectional antenna choices for cellular (and also directional that look omnidirectional). However the giveaway that the device is not a cell tower is the lack of any sizable ground equipment.
posted by forforf at 8:40 PM on October 3, 2006