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Musings on Civil Defence sirens

Air raid sirens are one of my interests, probably started by the original Silent Hill game when I was a kid. I think I also just like things that cover a lot under brief symbolism. I like flags and they represent an entire landmass, people, language, and way of doing things in just one icon. Likewise air raid sirens, properly called Civil Defence sirens, cover a variety of possible things going down with just a sound pattern. There are multiple tones for different uses, but most make use of the recognisable rising and falling wail to mark the likes of tornadoes, severe thunderstorms, flooding, and even volcano eruptions.

Civil Defence symbol.

I haven’t found sirens interesting for a while due to having seen rocket fire in Israel and having the Red Alert app on my phone so I get my own mini siren in England when Israel is attacked. They give me a feeling of dread now and have featured in nightmares.

But a recent discussion got me thinking about them again and I ended up going on a YouTube train. This, of course, got me overthinking how I’d deploy different siren tones in different situations if I were in charge of a civil defence system.

Before I knew it I was making needlessly thorough notes. So here we go:


Warning categories if I was in charge of a Civil Defence siren system


Red alert

Traditional up-and-down WWII air raid siren sound for air and nuclear attacks, or undefined emergencies.

Sound examples:




Black alert

5 short, sharp pulse tones, repeated. For times when people need to get inside the nearest building, lock the doors and windows because of a ground threat: Active shooter, terrorist attack, escaped prisoner, nearby hazardous explosion, escaped zoo animal, etc.

Basically a “get the fuck off the street” alarm. This is the one that would go off when the zombie apocalypse started.


The exact sound I want for this I’ve only heard in Israel and I’m not sure what it would be called for use with other sirens, but here’s a video example, you can hear the noise clearly at 0:40. If this wouldn’t get people moving then I don’t know what would because it’s fucking terrifying.



Yellow alert

Alternating (hi-lo) wail to symbolise approaching tornado, severe weather, earthquake, natural disaster that requires seeking shelter.

Spooky sound example:



Blue alert

Hi-lo pulses to instruct the seeking of higher ground for the likes of flooding, tsunamis, and acqua alta.

Sound example:



Orange alert

Steady pulse signal for emergencies that are not helped by you getting indoors. Such as approaching wildfires, pollution clouds and airborne hazards, loss of nearby hazard containment (but not close enough or appropriate for a black alert), lava flow, lahar, avalanche, and so forth.

Basically a “leave the area” alarm.

First sound shown in this video is the one I would use for this:

That’s gotta get people running away.



White alert

Long single tone to announce the “all-clear” after one of the other alerts, or used before an announcement over loudspeakers (probably on the same poles as the sirens), or for the commencement of memorial days and national holidays.



Voiceover through loudspeakers could announce the precise type of emergency if it’s not immediately obvious. There should also be lights on the poles that flash in appropriate patterns to help people with zero hearing discern which alert is being broadcast.

I’d test them at 5pm on Fridays by going through all of the alert tones in succession, flanked on either side by the white alert.

So the sirens above can basically be categorised as Get in, Get down, Get up, and Get out.




Sadly England doesn’t have much civil defence to speak of anymore, aside from flood sirens and alarms around oil refineries and similar places that could have potentially devastating emergencies.

We have a worrying lack of air raid shelters should a sudden war break out. It’s a shame that our siren infrastructure in particular has fallen to the wayside, because there are plenty of uses of it. England is seen as a place where weather, climate, and wildlife are much milder than elsewhere, but we do actually get tornadoes sometimes, and we get pretty horrendous storms that uproot trees and crush cars. If it were up to me, we’d have a fully functioning siren network.

Map of most likely tornado locations; the entire United Kingdom is highlighted.
Tornado aftermath in Birmingham, England, July 2005.



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