The Siren Board

http://www.youtube.com/watch?v=JEfYnByuTQ0
Here is a video of the mighty Chrysler Air Raid Siren. At 180 HP it was the most powerful warning siren ever put into production. It had a 70 dB radius of up to 4 miles as opposed to the 70 dB radius of under 10,000 feet as the loudest warning sirens of today. Of course it could be heard far beyond this 4 mile 70 dB radius. It's large warning radius was due to both is output of 138 dB at 100 feet and its frequency of 440 Hz. These wouldn't have any problem being heard from indoors at two miles!

The siren in the video has smaller modified horns than the original, but I'm surprised to see one of these fired up from indoors!! At least I'm glad to see that no one was standing in front of it! That much sound can kill!!

I can't help but wonder, what if that engine blew? Wouldn't it have caused harmed to the individuals standing nearby? Maybe I'm just over pre-cautious, but I wouldn't have stood near that when they fired it.

That and that one individual seemed to know about this siren, why didn't he recommend or hand out hearing protection to the other guys? It seems really irresponsible of him.

Anyways, I know very little of old world sirens since I'm young, and while I don't care for the design of the Chrysler Air-Raid Siren, it was capable of doing it's job and doing it well beyond the abilities of todays sirens.

Was this the very first Air Raid siren the US employed?

coyoteunknown wrote:I can't help but wonder, what if that engine blew? Wouldn't it have caused harmed to the individuals standing nearby? Maybe I'm just over pre-cautious, but I wouldn't have stood near that when they fired it.

I thought about that too... Any engine that's been sitting that long could be a hazard. I hope they at least changed the oil and hand-cranked the engine a few times to verify it wasn't ready to freeze up, or anything. Additionally, I hope they attacked the blower bearings with a grease gun first! If a dry bearing seized up and that chopper got loose, it would mow everything down in it's way like an out-of-control locomotive down hill

Charles

The 180 HP Chrysler siren was in a class by itself. Today's lower powered higher pitched sirens would sound like little more than noisy toys next to it. I was very surprised to see them firing it up from inside a building and only the operator using hearing protectors! This was very irresponsible of him! I hadn't even thought of the possibility of the engine blowing.

What also amazed me is that you could still barely hear the guy in the glasses shouting at 3:07 into the video. Listen carefully. I suppose it was because the horns were pointed the other way, but it was still inside the building. That building must have had very non-reflective walls, as the siren's output (on axis) would have exceeded his vocal efforts by a good 55 dB! At 90 degrees off axis it might be closer to only 35 dB.

Speaking of still being able to hear the man shouting, I once heard a dog barking in the next yard when I was standing near the base of an operating Thunderbolt siren. I thought that was rather amazing at the time. It had to be due to being off axis to the horn, along with little or no nearby reflectors.

One thing I will never forget is that when I was Publisher of Horn & Whistle magazine between 1988-1994, one of our members walked right up to the six horn array of a fully wound up Chrysler siren!! He said the sound made his vision blur. I guess!! I felt he was lucky to come out of this alive!! All he was wearing was ear protection.

coyoteunknown wrote:I can't help but wonder, what if that engine blew? Wouldn't it have caused harmed to the individuals standing nearby? Maybe I'm just over pre-cautious, but I wouldn't have stood near that when they fired it.

That and that one individual seemed to know about this siren, why didn't he recommend or hand out hearing protection to the other guys? It seems really irresponsible of him.

Anyways, I know very little of old world sirens since I'm young, and while I don't care for the design of the Chrysler Air-Raid Siren, it was capable of doing it's job and doing it well beyond the abilities of todays sirens.

Was this the very first Air Raid siren the US employed?