Federal Signal 500AT Prototype?

[Darley Champion]

It would have certainly been not practical to install... The 500-DH-TT (famously known also as the 550AT) was already a pain to install given how heavy it was

[FahmiRBLX]

It would have certainly been not practical to install... The 500-DH-TT (famously known also as the 550AT) was already a pain to install given how heavy it was

I thought it's because of its mount. I got a hassle of trying to mount one (Obviously in ROBLOX) on a 2-pole tower (The one just like one that has an 8 Port Allertor IRL, or simply like 2 inverted L that meets at the downside top, or simply a square arch) and ended up put one on an observation tower from the Toolbox Models front page that I even need to take its roof off. Seriously, it's big.

[Darley Champion]

The 500-DH-TT was not only one hell of a hulk of a siren, the mount exacerbated the difficulty to install these, the few pole mounted 500-DH-TTs had very large, metallic poles...

[Tyler]

The 500-DH-TT was not only one hell of a hulk of a siren, the mount exacerbated the difficulty to install these, the few pole mounted 500-DH-TTs had very large, metallic poles...

Well not only that, the 500 wasn't intended for pole mount in the first place. Federal said it in their ads that the 500 was a platform mounting siren. Frankly I find it as an excuse to not chip into the Thunderbolt's sales, because little did they know that the 500 would turn into a beast once they pushed it out and refined it. Ask anyone here that has heard a 10/12 SHTT in person and they will tell you that they are insanely powerful, and rightfully so once you see the beautifully engineered stator paired with a 21" monstrous rotor, with perhaps the most balanced intake design you'll ever find on a dual tone rotor. The 10/12 model has a special place in my heart, because it was the pinnacle of Federal's innovation in the 20th century, yet it was a huge flop because Federal wouldn't allow it to compete with Thunderbolt.

[Darley Champion]

Yes, the 500-series sirens were sadly ill-fated, I'm unsure why they made up that "excuse" to kill it off. fearing that it would outshine the Thunderbolt maybe?

Eithier way, 500-series sirens are pleasantly awesome to look at. I've never heard in person a 10-to-12 500-SH-TT but even on video they sound like they could shake the walls of nearby buildings.

[Jake_7367]

Maybe the prone-to-fault rotation mechanism was to blame.

[Tyler]

Maybe the prone-to-fault rotation mechanism was to blame.

There's nothing wrong with the mechanism at all. The only catch is that you have to take the head apart to replace the middle drive belt if you don't have a linking belt. If you take a look at all the 500 videos on YouTube, you'll notice that most of the belts started failing 30-40 years after the sirens were installed. I haven't seen a manual for a 500, but I imagine Federal recommends a linking belt for the assembly, so it saves you the trouble of taking the entire siren apart just to replace a belt.


This is the mechanism on a 500AT, highlighting the middle drive belt. This is the linking belt that came from the factory.

IMG_0790.jpg (733.93 KiB) Viewed 4690 times

[500AT]

The Dundee Twp. Fire Dept decided to mount their model 500 SH TT on a heavy-duty steel tower in back of their old fire station. They were concerned about the weight of the siren being pole mounted, and not being sturdy enough to support the siren in high-wind situations. This same structure would be ideal to support even the weight load of a model 550 DH TT. This photo was shot in the spring of 1982.

Federal Signal Corporation Model 500SH TT by Ronnie, on Flickr

[Jake_7367]

What a shame they retired it.

[NahIDee]

What a shame they retired it.

Since when was it retired?