[paradox460]

Sirens don't even need to be that complicated. A motor, a noise generator wheel (basically just a big spinning squirrelcage fan), and a horn. You could toggle them on/off with a simple relay/contactor.

[gojomo]

These "sirens" actually need to be able to play spoken announcements - something they did easily since about 2005, before the fumbled 2019-2024 shutdown/upgrade.

More history, through January 2022, via JWZ's blog:

https://www.jwz.org/blog/2022/01/the-reason-the-tuesday-noon...

[pastureofplenty]

JWZ doesn't like HN and doesn't want his site being linked to on here so your URL redirects to a crude image.

[jcgrillo]

what a delightfully epic troll, good on jwz :)))

[paradox460]

Now that you mention it, I do remember hearing the spoken message every Tuesday.

Still, a big loudspeaker is even simpler than a classical motorized siren. No moving parts!

[gojomo]

Yep! And as of the shutdown over 4 years ago, even if their control plane was insecure, they presumably had 119 working loudspeakers of the proper loudness/weatherproofing/etc.