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Description This photo is an image of a Federal Signal Thunderbolt (1000/1000T, Either is visually indistinguishable) with blower at the bottom of the picture. The Thunderbolt was mainly used for Civil Defence purposes during the Cold War. Some have fallen into a state of disrepair, some were decommissioned and replaced with modern tornado sirens and some were lucky enough to be maintained and are still alerting the general public to major threats. This siren is capable of producing 127dBC at 100ft or 30 metres and is most commonly available in Single Tone. Dual/fire tones were a decibel worse off to Single Tone, so Federal Signal quietly forgot about it. This siren met it's demise quite a few years later. This siren was one of the 'originals' of the Civil Defence era. The newer sirens are mainly intended for tornado warnings and other disasters, although very capable of sounding a Civil Defence warning. The other siren in this topic is an American Signal Penetrator P-50. This siren is huge (6' diameter) and is capable of pumping out 135dBc at 100ft or 30m, audible up to 10 square miles or 15 square kilometres. But still slightly 'quieter' than the very well known and feared Chryslers which belt out 138dBc at 100ft or 30m. Enough to implict severe hearing damage to within ten metres or 30 feet of the horns 'spread angle', unprotected. While the P-50 is still capable of being used for civil defence purposes, it's main intended purpose is to alert the people of Baran Park and surrounding areas in Milwaukee, WI to the threat of tornadoes.
Date 2006-02-18 (original upload date)
Source Originally from en.wikipedia; description page is/was here.
Author Original uploader was Thunderbolttactical at en.wikipedia
(Reusing this file)

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Original upload log

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  • 2006-02-18 03:55 Thunderbolttactical 604×800×8 (113234 bytes) This is a Thunderbolt 1000/1000T (Either is visually indistinguishable), mainly used for Civil Defence purposes during the Second World War. Some have fallen into a state of disrepair, some were decomissioned and replaced with modern tornado sirens and so

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EXIF data:
File name thunderbolt1000tsrn.jpg
Size, Mbytes 0.110580078125
Mime type image/jpeg
Camera manufacturer EASTMAN KODAK COMPANY
Orientation of image 1
Image resolution in width direction 230
Image resolution in height direction 230
Unit of X and Y resolution 2
Exposure time 3983/1000000 sec (0.003983)
F number f / 8
Exposure program 2
ISO speed rating 100
Compressed bits per pixel 2.66
Exif version 0220
Lens focal length 6 mm
Date and time original image was generated 2002:05:02 03:04:42
Date and time image was made digital data 2002:05:02 03:04:42
Meaning of each component 
Shutter speed 7.97
Aperture 6
Exposure bias 0
Maximum lens aperture 4.33
Metering mode 2
Supported Flashpix version 0100
Color space information 1
Exif image width 604
Exif image length 800
Exposure index 100
Sensing method 2
Scene type 
Digital zoom ratio 0
Focal length in 35 mm film 39 mm
Software used Adobe Photoshop 7.0
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