St. Louis County, Missouri Federal STH-10

[FedTB]

I discovered a couple of days ago through a YouTube video of a Whelen 2910 monthly test activation (siren located in Chesterfield) that there's a Federal STH-10 in St. Louis County's siren system. At the end of the 2910's test, the STH-10 can be heard wailing away in the distance, just a few miles away, though it sounds sick and is very low-toned. I had no idea that this siren even existed, and even more surprising is that it's still activated by St. Louis County E.M.A. and never taken offline when the massive new system of Whelen 2900-series sirens were installed in 2011.

The STH-10 is located at St. Louis County's water treatment plant in Chesterfield, at the Missouri-American Water Company building on Hog Hollow Road. I found a picture online of the water treatment plant and, sure enough, the STH-10 can be clearly seen, mounted on the roof of the office building. It's painted gray instead of the familiar "CD Yellow" of the old St. Louis County Civil Defense siren system installed back in the 1950s and '60s. I have no idea how old this siren is, when it was installed, etc. But it doesn't have the typical high pitched tone of a "healthy" STH-10 and is, instead, low-toned, like the motor is burning out.

The building itself is old and I'm assuming that the purpose of the siren being installed there was for CD use and not as some sort of warning siren in case of an accident at the plant. It would be interesting to know the STH-10's history.

[metalstorm]

Now that's an oddball especially since it's being activated with the newer system. I wonder why it wasn't replaced with a 2905. STL County has a few of the smaller 2900 series as either gap fillers installed after the big upgrade or that were part of the previous system and kept

[FedTB]

Yes it is an oddball! I would find it hard to believe that the powers-that-be that planned the new siren system would've "forgotten" that the STH-10 was there. I don't know anyone at St. Louis County's EMA to call and ask, and I'd feel odd if I did call. I checked the official online map of the siren locations for the county and the STH-10 is not on there; no surprise there.

St. Louis County's siren system is tested on the first Monday of the month at 11 AM, weather permitting of course. And tomorrow is test day but I have something else going at that time but plan on catching a future test of the STH-10.

[uncommonsense]

I'm guessing it must be owned/activated by the plant or an independent entity. That siren wasn't on any of the documentation about the existing sirens in the county when the 2910s were going in.

[SiraTone]

There’s also an STL-10 near by down the road at the Howard Faust treatment plant which is another water plant. So Chesterfield has an active STH-10 and STL-10.

[FedTB]

Sira Tone, it's funny that you mention the STL-10, which I didn't even know existed at that plant, because in the video that I mention, it sounds more like an STL-10 than an STH-10, since it's the lower tone. So maybe it IS the STL-10 that's heard and not the STH-10.

BTW, it's the Howard Bend plant, not Howard Faust.

Thanks for the additional info.!

[SiraTone]

There’s a video of both the STH-10 and STL-10 going off with ambience.

[FedTB]

SiraTone, I watched that YouTube video and the still picture shows the Howard Bend Station water works building as well and a gray STH-10 can clearly be seen, but no STL-10. So it seems that one of the STH-10's really is "sick" with a bad motor that makes the siren's tone much lower than normal, making it sound similar to a STL-10. At least that's my conclusion.