[what the--]Hemi-Powered 180hp ULTRA SIREN

[Grind Hard]

http://www.youtube.com/watch?v=IAMiTfSU7ZA

http://www.victorysiren.com/x/index.htm

Clearly, I need one of these. Those god-damned Rap Cars would not stand a CHANCE. People would never cut me off in traffic again. McDonalds would never screw up my order either.

....

Who am I kidding I'd go deaf the first day I owned it and end up in prison.

Still... 180hp... That's quite a few horses under the hood!

[GKman]

Thanx for posting. A real kick.

Sure I'm not the only one reminded of Kurt Vonnegut's reference to the fellow who acquired the Berlin air raid siren powered by a Messerschmidt engine for his little volunteer fire department. Think the book was God Bless You Mr Rosewater. Looks like fact is as strange as fiction.

[vpt]

Nice!


For some reason I want one.

[Weston Bye]

Although not what we do, a guy once brought an electric motor driven siren from a fire engine in the front door to see if we could convert it from 6V to 12V. Being as close to an expert on such things as we had, the siren ended up on my desk.

Well..... I just had to test it. I put on my ear protection and fired it up with a bench power supply.

Even with the door closed, and the concrete block walls around my office, and the poured concrete floor of the conference room above, everyone thought the tornado siren up the street was going off.

After an amusing distraction, I sent it back, saying no, we couldn't help the guy, and went back to more important but less enjoyable tasks.

[Fasttrack]

I spent a couple days pawing through the "internets" learning about air raid sirens a couple of months ago. Really cool stuff! Apparently, there is an entire community of people that restore old air raid sirens, foghorns and freighter horns. There are some legal hoops you have to jump through to sound any of these ... for obvious reasons

This one always makes me laugh...
http://www.youtube.com/watch?v=hMy0H_ySfp0

Or how about this ... next time someone is tailgating you, just let 'er rip
http://www.youtube.com/watch?v=6Maso...feature=relmfu

[Grind Hard]

I'd love to get a look at the blower section, taken apart. I bet there is some amazing curved blades/vanes in there.

[Ed P]

Here's a 2003 article from Invention & Technology:

FEEL THE NOISE

THE ART AND SCIENCE OF MAKING SOUND ALARMING

BY MICHAEL LAMM

IN 1991 HARRY BARRY FOUND THE NOISEMAKER OF HIS DREAMS: a huge air-raid siren from the 195Os. It weighed more than .S1OOO pounds and was powered by a .33 I-cubic-inch V-8 Chrysler industrial gasoline engine. Barry, who has been collecting sirens, horns, and whistles since he was 15, had his latest treasure hauled from Detroit to his home in northeastern Pennsylvania. Might years later, in 1999, he invited Mric Larson, a professional pipeorgan restorer and fellow siren collector, to hear it in full song.

The two men towed the siren, which was mounted on a trailer, to a remote wooded area by a lake. Barry started the engine and let it warm up, and Larson noticed that the V-8 had no mufflers. In the Summer 2000 issue of Horn & Whistle, Larson told what happened next:

“When the engine had warmed up sufficiently, Harry then threw the clutch engaging the compressor and siren rotor plate. Although at this point the V-8 engine was probably only idling at 500 RPM, the siren began to produce sound, an enormously powerful and deep tone, not unlike the bass of a pipeorgan flue pipe but much louder and with more harmonic development. … Finally, Harry flipped a switch that activated a solenoid attached to the engine throttle.

“At this point, the engine began to pick up speed and reached top speed in about ten seconds. 1 stood at a respectful distance to the side and behind the huge siren and held my ears. As the machine approached rated speed, I could actually feel the pavement of the road vibrate.… At first I thought I was feeling mechanical vibration from the engine and the compressor, but the rubber tires of the trailer would have absorbed that. The vibration of the ground was strictly the result of the siren sound output. Finally Harry flipped the switch to the other position and the siren slowed down until again it reached idle speed.

“Then he invited me to try it. I stepped up on the trailer and went to the small control panel on the side of the engine compartment to flip the switch. Although I now wore Harry’s hearing protectors, it soon became evident that they weren’t sufficient and I slid a finger under each earmuff to hold my ears. At this point I was standing probably about seven feet behind the compressor-siren assembly. Suddenly everything else disppeared from existertee.… I looked briefly at my clothes and saw the fabric appeared blurry. My garments were vibrating at this same frequency! I even felt the sound in my beard and mustache.… My nose and the area just below my eyes began to ache slightly, and I noticed my eyes beginning to tear over.…

IN ONE LIGHTHOUSE, NOISE FROM THE SIREN WAS INTENSE ENOUGH TO EXTINGUISH LIGHTS, CURDLE MILK, AND KILL CHICKENS IN THE EGG.
“I felt as though I could reach out and touch the sound, or lean on it or even sit on it, maybe even pick it up with a shovel or swim in it. It was that physically real, as though the sound itself had taken on a new and somewhat viscous, liquid form. Now, I had to figure out how to shut this thing down without removing my fingers from my ears. Finally, I reached up and hit the switch with my right elbow! Then I stepped down and back as the siren once more slowed to idle speed.” While every pastime has its own particular joys, very few collectors of stamps, coins, or shaving mugs can report such a visceral experience with their hobby...
The Chrysler Corporation was also developing an air-raid siren early in World War II, and its researchers met with Bell engineers in March 1942. This led to production of the ChryslerBeIl Victory Siren, which was powered by an in-line, eightcylinder, 140-horsepower Chrysler automobile engine. The twostage blower produced five pounds per square inch (psi) of pressure, for a sound output of 137 decibels (dB) at a distance of 100 feet, with a frequency of 430 Hz. To give an idea of how loud 137 dB is, a jet aircraft engine at full throttle produces about 130 dB at 100 feet. A shotgun blast generates roughly 140 dB at the muzzle (every 10 decibels represents a doubling of loudness as perceived by the average listener).

Towns and cities across the United States and Canada ordered Victory sirens to warn citizens of air raids, tornadoes, and other disasters. Despite a 1942 price of $3,760 per siren (about $41,000 today), Detroit and Chicago bought 20 apiece. New York and Cincinnati purchased 10 apiece. In some instances the Chrysler-Bell Victory Sirens served their buyers into the early Cold War. None are known to survive today.

From 1952 through 1957 Chrysler produced an improved version of its World War II siren driven by a 180-horsepower hemi V-8. This was an industrial version of Chrysler’s famous automobile engine, and it powered the siren through an automotive fluid coupling. The hemi V-8 drove a three-stage centrifugal compressor at 4,500 rpm. The compressor housing was about 42 inches across and 18 inches deep. The entire output of the compressor section then entered a circular chamber to which six cast-aluminum horns were attached.

The horn throats, set at 60-degree intervals, formed a ring around the front of the siren. Just inside this circle was a round, half-ton, steel rotor plate with six ports. As this plate rotated, also at 4,500 rpm, the ports alternately opened and closed the throats of the six horns, creating a high-amplitude sound wave. The pressure inside the Chrysler siren was less than seven psi, but the compressor managed to move a huge quantity of air: 2,610 cubic feet per minute. Since the Chrysler siren’s blast was highly directional, many cities mounted their sirens on rotating turntables.

In cold climates, engine-block heaters and battery warmers helped keep sirens on full alert in winter. Since inactivity tended to make the system unreliable, sirens were usually tested for 15 minutes at least once a month. Sirens could be started and shut down remotely, by either dedicated telephone lines or radio signals. The early Victory sirens were also equipped with a seat and a control panel so that an operator could start and stop the device manually.

New warning methods have taken precedence in many situations, but sirens still have their uses. In Hawaii, for example, large sirens warn of tsunamis (tidal waves) and tropical storms. Fire departments stick to their mechanical sirens because they are louder than the electronic variety. With today’s motorists sealed into their cars with stereos blaring or cell phones in their ears, firefighters want to be sure they will be heard. While no one wants air-raid and civil defense signals to be as familiar as they were during the Cold War, it seems unlikely that the sound of a siren’s lusty wail will ever vanish completely.

Ed P