The Siren Board

Here's another interesting siren from the Historical US Archive:


http://www.airraidsirens.com/images/corbis3.jpg


This bohemoth terrorized New York city between 1950 and around 1978 when they were removed. There were very few of them, perhaps 25.

The rest of the 741 sirens NYC operated were all much smaller

Who built them? I have only seen them in New York City, no place else.

They did rotate, they climbed to a pitch of around 440 Hz.

They were mostly mounted on very tall buildings, which actually cut down their range somewhat.

That is a HOR Super Sirex, it does rotate (unless the rotator is broken as appears to be common with them as they age) and is available in both dual tone and single tone. They are really, really big too!

Dave

How did they rotate?

Did it have an additional motor for rotation, or did the centrifugal force rotate it by itself?

Does it have two siren motors, one for each side, or only one in the center that rotates both shafts?

Is that the same as a Hormann siren?


Thank you,

Larry

One motor spins both rotors.

There is a separate motor for rotation of the siren head. If I'm not mistaken, the motor for that task is on the left side, on a length-based axis. So there must be a big gear connected to the siren head, inside that big circular base.

Nice photo. Thanks.

At first I thoughthe two cones were sound projecting horns.
Buthey aren't.

Why didn'they have the air enter the rotors from the inside (motor side) and have larger horns attached around the stators?

Seems that would have been much louder and sent less sound skyward.
But that roof probably reflected a lot downwards, too.
I bet it is nothere just for weather protection but also sound reflection.

Where are these sirens now? All scrapped?