The Siren Board

Hi everyone, I am a new member and I am hoping to find out more about a Crompton Air Raid siren that was used in Tamworth NSW Australia in WW2. It still works. I am attaching a picture. I am a volunteer cataloguer at the Tamworth Powerstation Museum and this is part of the collection. Thanks!
From the ID Plate: Crompton Parkinson Proprietary Limited (Australia).
6682626, 2.75 HP, 12900 RPM, 3PH, 50 cycles, 400/440 volts, 3.8 Amps, Star, Cont rating.
Supplied by Noyes Bros. (Sydney) Ltd. 115 Clarence St. Sydney.
Another Plate: Supplied by British General Electric Co. Pty. Ltd.

Very very cool siren. Never seen one like that before. My guess would be is that this siren was manufactured by the same company that made the "Carter" style sirens used in England during WW2 and throughout the Cold War. My guess would be is that it is a very rare siren.

What's the port ratio, 12/14? I know there was a video of one running for a fire call over there. I can't find it.

Looks like 12/12. But wow, pushing 13000 RPM, or just a typo?

Welcome aboard!

stormsetter4 wrote:Very very cool siren. Never seen one like that before. My guess would be is that this siren was manufactured by the same company that made the "Carter" style sirens used in England during WW2 and throughout the Cold War. My guess would be is that it is a very rare siren.

I don't think so, but it does have a tag on it displaying a different English electronics manufacturer. Since I live in England, I could look into it though.

Thanks! And yes a typo should read 2900 rpm thanks for picking that up.
How do i find out/work out the port ratio?

Nice siren. I not seeing one like it before. You can find out how many ports it has by counting the holes in the stators or by counting the blades on the rotors/fans & count them individually by doing one rotor then the other & you should then get a number for how many ports this siren has for each rotor & stator. For example the siren in my avatar is an 8 port as it has 8 blades.