The Siren Board

http://www.youtube.com/watch?v=3pL8Ic4Linc

Is this siren's rotor air powered?

I have a little toy which is blown to make it spin and sounds like a siren.

Does this siren operate on the same principle?

Michel, who sent this video to me, said it was pneumatic powered.
Also said it was a Rickmers Werft.

Is this something unusual?

Is there anything remarkable about these sirens?
Especially loud?

Interesting how the sound immediately dies off at the end.
No wind-down.

I like the 2t22 better not only for it's dual-tone minor third interval but also the marvelous long wind-down to silence.

First of all, great video, and thanks for posting it here.

The rotor gets nothing but the air from the compressor. The rotor itself is cylinder, made of brass, I think. You'd need a huge impeller-style rotor to suck in as much air as that compressor gives. With a compressor powerful enough, you can make the rotor smaller, as the case is in this.

This HLS siren does not have the air spinning the rotor, but a very fast electric motor.

Rickmers Werft must be another company uncovered in its production of the HLS.

The thing that I find remarkable about these sirens is that they can output (131) Decibels at a hundred feet from them. One of the key factors for such sound level in all directions is the remarkably small rotor and the fact that the rotor and stator only have four ports, preventing too much loss of air from the compressor.

its the same one on that video I found on youtube