Operating the Chrysler Air
Raid Siren
David Stall is fortunate enough to own
one of the three fully functioning Chrysler Air Raid Sirens that exist
today. He also has his siren located in rural Texas surrounded by
lots of open space, which is very helpful since he loves to run the
Hemi® and blow the siren.
The clear zone (minimum safe
distance) extends 320 feet. Even then, if you are in front of the
siren it would be uncomfortable and prolonged exposure could damage your
hearing.
The Chrysler Siren is very directional
and the majority of its sound force is directed out in front of the
giant projector horns. However, there is still lots of sound power
to go around. Just operating the siren from the side control panel
requires a minimum hearing protection of 30dB.
Recording of the BigRed™
Chrysler Air Raid Siren!
Sound Clip #3 -
Start & Idle [ CLICK HERE FOR SOUND
] .WAV file - 22 seconds (480KB)
This is a recording of BigRed ™
on May 23, 2003,
the first time
it was started and run in Texas. The propane tank was turned on, the
ignition hotwired, and the starter cranked. After cranking for
only 3½
seconds and on the very first try, this giant Chrysler Siren roared to
life. The engine was loud, but the growl of the siren soon drowns
out the engine noise with a jet engine like roar.
Sound Clip #4 -
Rev & Stop [ CLICK HERE FOR SOUND
] .WAV file - 23 seconds (499KB)
This is a recording of David revving the Hemi
engine of BigRed™ and shutting it down after the very first time
it was started and run in Texas (May 23,
2003). This was the siren's first test run. If
you listen carefully at the end of the clip you can hear the squeaky
noise of the turntable drive pulleys. Some
additional work, including lubrication of the compressor bearings, will
be performed before it is run up to full throttle.
( Sound clips #3 &
#4 were recorded by David Stall using a Marantz professional cassette
recorder model PMD222 and an Electro-Voice dynamic microphone model 635A
located six feet from the radiator end of the siren. The automatic
level control was used. As a result, the recorded volume of the
engine decreases significantly as the siren volume increases. )
Sound Clip #5 -
Start [ CLICK HERE FOR SOUND
] .WAV file - 3 seconds (176KB)
This is a recording of BigRed™
on May 24, 2003, the second time
it was started and run in Texas. This time it started instantly after cranking for
only a
second and on the very first try.
( Sound Clip #5 was recorded by David Stall using a Marantz professional cassette
recorder model PMD222 and an Electro-Voice dynamic microphone model 635A
located six feet from the radiator end of the siren. The recording
level was manually set. As a result, once the engine started
growling the siren the volume of the siren over drove the input and
caused distortion that rendered the remainder of the recording unusable. )
Sound Clip #6 -
Start & Idle - No Siren [ CLICK HERE FOR SOUND
]
.WAV file - 45 seconds (986KB)
This is a recording of BigRed™
on May 25, 2003, the third time
it was started and run in Texas. This time it we were testing the clutch
and the engine was started and idled with the compressor clutch
disengaged.
Sound Clip #7 -
Engaging the Siren Clutch at Idle Speed [
CLICK HERE FOR SOUND
]
.WAV file - 6 seconds (148KB)
This is a recording of BigRed™
on May 25, 2003, again during the third time
it was run in Texas. Continuing the testing of the clutch. In this
clip you can hear the engine load when the clutch engages the
compressor, then of course you can hear the siren at idle.
Sound Clip #8 -
Full Run [ CLICK HERE FOR SOUND
]
.WAV file - 59 seconds (1.25MB)
This is a long recording of BigRed™
on May 25, 2003, during its entire fourth
run in Texas. Again the engine is started with the clutch disengaged,
idled, clutch engaged, and run up to about 3000 RPM, a hesitation while
checking performance, then 4600 RPM - full throttle! (Note: The
clutch works great, in the future the engine will be usually started and
stopped with the clutch in either engaged or disengaged position.)
Sound Clip #9 -
Gunning the Big Hemi - No Siren [
CLICK HERE FOR SOUND
]
.WAV file - 8 seconds (176KB)
This is a brief recording of the Hemi engine that
drives BigRed™ being gunned
on May 26, 2003, during its sixth
run in Texas. The clutch is disengaged and
there is no siren sound. If you're a Chrysler Hemi or big engine
fan this clip is for you! It's easy to see how these engines ended
up in lots of hot rods during the 1970's.
( Sound Clips #6,
#7, #8 & #9 were recorded by David Stall using a Marantz professional cassette
recorder model PMD222 and an Electro-Voice dynamic microphone model 635A
located 40 feet away at the rear quadrant of the siren. The
automatic level control was used. As a result, the recorded volume
of the engine is the same as the siren, which of course is tremendously
louder. )
These
are recordings of Harry Barry's Detroit,
Michigan, Chrysler Air Raid Siren.
Sound Clip #1 -
Start & Idle [ CLICK HERE FOR SOUND
] .WAV file - 12 seconds (269KB)
In this sound clip you can hear the big V-8
Chrysler engine start up and the impressive growl of the siren at normal
idle speed (650 RPM).
Sound Clip #2 -
Winding Up [ CLICK HERE FOR SOUND
] .WAV file - 20 seconds (225KB)
Listen
carefully and you can hear the big V-8 Chrysler engine rev up and the
flutter of the siren rotor as it comes up to full speed (4600 RPM).
Sound Clip #10 -
Warning Signal [ CLICK HERE FOR SOUND
] .WAV file - 24 sec.(256KB)
This is a
recording of Harry Barry's Detroit siren as heard five miles away.
Although the siren was pointed in Harry's direction, it was not visible
over a ridge between the two distant points. The siren was mounted
on a trailer and not at optimum height for sound coverage. At this
distance it takes the siren sound about twenty-four seconds (same length
of time as this clip) to travel from the
siren to the listener. The
siren volume was estimated to be 55 to 58 dB at this distance!
( Sound Clip #1 was captured by David Stall off a videotape of Harry Barry's
Detroit Siren. Sound Clip #2 comes courtesy of
Andy Stoy, and was captured by Mike Grogan off a videotape of Harry
Barry's Detroit Siren. Sound Clip #10 was captured by David Stall off a videotape Harry Barry
recorded of his Detroit Siren in Pennsylvania on December 28, 2003. )
The Operating & Maintenance Manual gives
this description of the
Chrysler Air Raid Siren warning signal.
WARNING SIGNAL
The Warning Signal consists of a variation in the sound tone of the
Siren called "Warbling". This is produced by increasing the speed of the
Siren Engine to 4600 R. P. M. then decreasing the speed of the Siren
Engine, repeating the cycle in regular intervals for a Three minute
period.
The required intervals can be regulated by using the
second hand of an ordinary watch, a satisfactory fluctuating note will
be obtained by Pressure on the Signal switch on an Eight second "ON" and
Four
second "OFF" cycle, repeating that sequence for the Three minute
duration of the "Warning" Signal.
THE TIME PERIOD OF THE "WARNING" AND THE "ALL
CLEAR" SIGNALS IS ESTABLISHED BY THE FEDERAL CIVIL DEFENSE
ADMINISTRATION; THE PROCEDURE FOR PRODUCING THE SIGNAL HAS BEEN
ACCEPTED BY VARIOUS MUNICIPALITIES AND IS AT THIS TIME CONSIDERED
UNIVERSAL THROUGHOUT THE COUNTRY, IT IS HOWEVER, SUBJECT TO GOVERNMENT
REGULATIONS AND CHANGES.
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