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Thunderbolt 1000/1000T Civil Defense siren. 127 dBc @ 100 ft or 30 m

A civil defense siren (also referred to as an air raid siren, tornado siren, or outdoor warning siren) is a mechanical device (modern day sirens are electrically-powered) for generating sound to provide warning of approaching danger and sometimes to indicate when the danger has passed. Image File history File links Gnome-globe. ... Image File history File linksMetadata Download high resolution version (604x800, 110 KB) Summary This photo is an image of a Federal Signal Thunderbolt (1000/1000T, Either is visually indistinguishable) with blower at the bottom of the picture. ... Image File history File linksMetadata Download high resolution version (604x800, 110 KB) Summary This photo is an image of a Federal Signal Thunderbolt (1000/1000T, Either is visually indistinguishable) with blower at the bottom of the picture. ... This article is about devices that perform tasks. ... For delivered electrical power, see Electrical power industry. ... This article is about audible acoustic waves. ...

Initially designed to warn of air raids in World War II, they were adapted to warn of nuclear attack and of natural phenomena such as tornadoes. The generalized nature of the siren led to many of them being replaced with more specialized warnings, such as the Emergency Alert System. Strategic bombing is a military strategem used in a total war style campaign that attempts to destroy the economic ability of a nation-state to wage war. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Nuclear War is a card game designed by Douglas Malewicki, and originally published in 1966. ... This article is about the weather phenomenon. ... The Emergency Alert System (EAS) is a national system in the U.S. put into place in 1994, superseding the Emergency Broadcast System (EBS) and is jointly coordinated by the Federal Communications Commission (FCC), Federal Emergency Managemant Agency (FEMA), and the National Weather Service (NWS). ...

Sound is generated by a motor driving a shaft with fans on each end, one fan having a few more blades than the other. Around each fan is a housing with a number of cut slots to match the number of fan blades. The blades draw air in at the end and force it out through the slots in the housing in rapid pulses, which produces the sound. Modern sirens can reach up to, but not commonly, 135 decibels when measured 100 feet away from the siren; the loudest confirmed siren ever produced was the Chrysler Air Raid Siren, producing 138 dB at 100 feet. The Chrysler Air Raid Siren used a 180 hp V-8 hemi engine to drive the siren and weighed 5543 lb.^[1] For other kinds of motors, see motor. ... A shaft can be Look up shaft in Wiktionary, the free dictionary. ... For other uses, see Fan. ... A blade is the flat part of a tool or weapon that normally has a cutting edge and/or pointed end typically made of a metal, most recently, steel intentionally used to cut, stab, slice, throw, thrust, or strike an animate or inainimate object. ... Air redirects here. ... It has been suggested that this article or section be merged into sound pressure level. ...

Many warning sirens have a sound that is distinct from that used by emergency vehicles due to use of two simultaneous tones, usually in a 5:6 frequency ratio (a minor third). Pitch is the perceived fundamental frequency of a sound. ... A minor third is the smaller of two commonly occurring musical intervals compounded of two steps of the diatonic scale. ...

Some newer sirens have the ability to broadcast voice messages over large areas, depending on winds and noise. These electronic sirens are similar to electromechanical sirens; however, they rely on a series of large loudspeakers to produce sound. However, there is some question about the ability of a system of electronic sirens to broadcast a voice message with sufficient intelligibility over long distances - not only does the sound echo off some surfaces, the sound could have multiple arrival times from widely-spaced siren sites. Broadcasting is the distribution of audio and/or video signals which transmit programs to an audience. ... School public address system A public address or PA system is an electronic amplification system with a mixer, amplifier and loudspeakers, used to reinforce a given sound (e. ... For other uses, see Wind (disambiguation). ... Environmental Noise is unwanted sound, which may cause both nuisance and damage to health. ... For the Marty Friedman album, see Loudspeaker (album) An inexpensive low fidelity 3. ... In audio signal processing and acoustics, an echo (plural echoes) is a reflection of sound, arriving at the listener some time after the direct sound. ...

However, the relative simplicity, efficiency, and easily-serviceable design of modern electronic warning systems, in addition to the ability to broadcast any type of warning signal desired, makes them an attractive alternative for many municipalities.

Historical warning tones

An air-raid siren in Nice, France is still operational.

During World War II for a "Red Warning" of approaching danger, the siren produced a tone that rose and fell regularly between one high and one low tone. Image File history File linksMetadata Download high resolution version (2848x2136, 3077 KB) Summary An old air-raid siren found on top of the Parc du Château in Nice. ... Image File history File linksMetadata Download high resolution version (2848x2136, 3077 KB) Summary An old air-raid siren found on top of the Parc du Château in Nice. ... Time Zone CET (GMT +1) Coordinates Administration Country Region Provence-Alpes-Côte dAzur Department Alpes-Maritimes (06) Intercommunality Community of Agglomeration Nice Côte dAzur Mayor Jacques Peyrat (UMP) (since 1995) Statistics Land area¹ 71. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000...

A "White Warning" (All Clear) was a single continuous tone. Another alternating tone signified a "take cover" warning for immediate danger.

After World War II, two further warnings were introduced for nuclear attack - a "Grey Warning" indicated approaching nuclear fallout with a 2½ minute warning of long steady tones divided by equal periods of silence, the silence being created with a manual shutter or electric solenoid. Fallout is the residual radiation hazard from a nuclear explosion, so named because it falls out of the atmosphere into which it is spread during the explosion. ...

A "Black Warning", also for manual sirens, was either a Morse code 'D' (–··) or three quick tones, indicating imminent danger of fallout. 1922 Chart of the Morse Code Letters and Numerals Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message. ... Pitch is the perceived fundamental frequency of a sound. ...

These warnings were not used in the United States.

Current warning tones

Usage in the United States

ACA P-50 Civil Defense Siren. 135 dBc @ 100 ft or 30 m

Today, the most common tones sirens in the United States produce are "Alert," "Attack," "Wail," and "Hi-Lo." Image File history File linksMetadata Download high resolution version (1200x800, 316 KB)Copyright © 2005 Sulfur An example of a civil defense siren (also called a warning siren or tornado siren), found at Baran Park in Milwaukee, WI. Permission is granted to copy, distribute and/or modify this document under the... Image File history File linksMetadata Download high resolution version (1200x800, 316 KB)Copyright © 2005 Sulfur An example of a civil defense siren (also called a warning siren or tornado siren), found at Baran Park in Milwaukee, WI. Permission is granted to copy, distribute and/or modify this document under the...

While the tones used vary in some locations, the most common tone, the "Alert" is widely used by municipalities to warn citizens of impending extremely severe weather, particularly tornadoes. The sound of the "Alert" is a steady continuous note.

The "Attack" tone may also be used to warn of severe weather, but it is widely believed that this tone is to be reserved for an impending attack on the United States. This tone is best described as having a rising and falling sound ("wavering").

Finally, the "Hi-Lo" Fire siren tone can sometimes be used by local volunteer fire departments to alert firefighters of an emergency. This tone is also used in some cities to warn of the potential for flash flooding. The "Hi-Lo" tone is a continuous alternating higher pitched and lower pitched sound, similar to police sirens in Europe. It has been suggested that this article or section be merged with Siren (noisemaker). ... Firefighter with an axe A firefighter, sometimes still called a fireman though women have increasingly joined firefighting units, is a person who is trained and equipped to put out fires, rescue people and in some areas provide emergency medical services. ... For other uses, see Europe (disambiguation). ...

In some locations, sirens are also used to alert the public to releases of hazardous materials, such as chemicals from a derailed train car or a manufacturing plant. A hazardous material (HAZMAT) is any solid, liquid, or gas that can cause harm to humans, other living organisms, or the environment due to being radioactive, flammable, explosive, toxic, corrosive, a biohazard, an oxidizer, an asphyxiant, or capable of causing severe allergic reactions. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... The only derailment of a Shinkansen in normal operations occurred as a result of the 2004 Chūetsu earthquake; no injuries were reported from this accident. ... For other uses, see Train (disambiguation). ... A factory (previously manufactory) or manufacturing plant is a large industrial building where workers manufacture goods or products. ...

Sirens in integrated public warning systems

Sirens are sometimes used as part of an integrated warning system that links sirens with other warning media such as the radio and TV Emergency Alert System, NOAA Weather Radio, telephone alerting systems and wireless alerting systems in the United States and the Emergency Public Warning System in the Canadian province of Alberta. This integrated approach enhances the credibility of warnings and reduces the risk of their being dismissed as false alarms by corroborating the warning messages through multiple media. The Common Alerting Protocol is a technical standard for this sort of multi-system integration. The Emergency Alert System (EAS) is a national system in the U.S. put into place in 1994, superseding the Emergency Broadcast System (EBS) and is jointly coordinated by the Federal Communications Commission (FCC), Federal Emergency Managemant Agency (FEMA), and the National Weather Service (NWS). ... NOAA Weather Radio (NWR) is an American network of radio stations broadcasting continuous weather information directly from a nearby National Weather Service office [1]. NWR broadcasts National Weather Service warnings, watches, forecasts and other hazard information 24 hours a day. ... The Emergency Public Warning System is a system used in the province of Alberta, Canada, whereby local or provincial authorities can warn the public about impending or current emergencies affecting their area. ... For other uses, see Alberta (disambiguation). ... The Common Alerting Protocol (CAP) is an XML-based data format for exchanging emergency alerts and public warnings among different alerting technologies. ...

Types of sirens

Mechanical sirens (direct driven)

Federal Signal SD-10

A mechanical siren uses a rotor and stator to "chop" an air stream, which is forced through the siren by radial vanes in the spinning rotor. An example of this type of siren is the The Federal Signal "2T22" [2], which was originally developed during the Cold War and produced from the early 1950s to the late 1980s. This particular design employs dual rotors and stators to sound each pitch. Because the sound power output of this type of siren is the same in every direction at all times, it is described as omnidirectional. The Federal 2T22 was also marketed in a 3-signal configuration known as the Federal 3T22, which had capabilities for a "hi-lo" signal. Image File history File linksMetadata Download high resolution version (1200x800, 316 KB)Copyright © 2005 Sulfur An example of a civil defense siren (also called a warning siren or tornado siren), found at Baran Park in Milwaukee, WI. Permission is granted to copy, distribute and/or modify this document under the... Image File history File linksMetadata Download high resolution version (1200x800, 316 KB)Copyright © 2005 Sulfur An example of a civil defense siren (also called a warning siren or tornado siren), found at Baran Park in Milwaukee, WI. Permission is granted to copy, distribute and/or modify this document under the...

While some mechanical sirens produce sound in all directions simultaneously, other designs produce sound in only one direction, while employing a rotator mechanism to turn the siren head throughout 360 degrees. One such siren is the American Signal "Allertor" [3]. This siren also produces two pitches simultaneously in a musical interval, but in this case the rotor and stator incorporate separate sections for producing each pitch.

An example of such a siren being produced today is the Federal Signal Model 2001 series. Introduced in the late 80s, it is capable of battery backup. There are two separate motors in the 2001. One powers the siren rotor, while another powers the rotator mechanism[4].

One rare type of mechanical siren does not rotate or produce equal sound output in all directions. The Federal Signal "Thunderbeam" siren [5] employs a slowly rotating disc below the siren, which directs the siren's output throughout 360 degrees. This same method, applied differently, produces the distinctive sound character of the Leslie loudspeaker, but the rotation of the disc in the Thunderbeam is far too slow to produce the "warbling" sound associated with the Leslie loudspeaker. The Leslie speaker is a specially constructed amplifier/loudspeaker used to create special audio effects utilizing the Doppler effect. ...

"Supercharged" electromechanical sirens

Federal Signal Thunderbolt 1003

The Federal Signal Thunderbolt series is the most recognizable of all warning sirens due to its unique shape and design. It creates a very distinct tone, made specifically to get the attention of people. "Thunderbolt" sirens use a separate blower to force air through the rotor and produce greater air movement with each pulse, thus they are described as supercharged^{[citation needed]}. Image File history File linksMetadata Download high resolution version (800x1200, 884 KB) Summary Federal Signal Thunderbolt 1003, Civil defense, City hall, Lebanon, Illinois, 2006. ... Image File history File linksMetadata Download high resolution version (800x1200, 884 KB) Summary Federal Signal Thunderbolt 1003, Civil defense, City hall, Lebanon, Illinois, 2006. ... Thunderbolt Model 1003 The Thunderbolt siren was an electro-mechanical warning siren once manufactured in the United States by Federal Signal Corporation. ...

Specially-designed horns having an exponential profile amplify the sound, causing the air at the end of the horn to be displaced the same distance as air in the throat of the horn with the passage of each wavefront. This lends a unique "distorted" character to the sound of these sirens as the throat of the horn is overloaded.

Within the Thunderbolt product line, three different configurations were offered. The Thunderbolt 1000 is a single tone siren, and the Thunderbolt 1000T is a dual tone siren. The Thunderbolt 1003 is essentially the same as the Thunderbolt 1000T, except that it employs solenoid-actuated slide valves to create a "hi-lo" signal.

Other "supercharged" sirens (having a separate blower for supplying air) include the American Signal (ASC) "Hurricane" [6].

A variation on the 'Supercharged' electromechanical siren is the pneumatic Hochleistungssirene (HLS), produced by the German firm Pintsch-Bamag, and later by the German firm Hörmann. Soon afterward, Hörmann improved on the design to create the HLS 273, which did away with the massive siren head of the original in favor of a more compact head and cast aluminum exponential-profile horns.

These sirens stored an enormous reservoir of compressed air, recharged periodically by a diesel engine-driven compressor in a vault in the base of the massive siren unit. The later HLS 273 located the large (6000 liter) air tank underground beside the machinery vault, instead of in the mast itself as in the earlier HLS units. [7]

Electronic sirens

American Signal AL-8000 in O'Fallon, Illinois

Electronic sirens produce their sound in a fashion that is fundamentally different from electromechanical sirens. Instead of a motor-driven rotor spinning inside a stator, electronic sirens consist of an electronic tone generator, a high-power amplifier, and a horn speaker typically incorporating one or a multiple of electrodynamic transducers. Image File history File linksMetadata Download high resolution version (800x1200, 645 KB) Summary AL-8000, Alertronic High Powered Voice Siren, Civil defense, OFallon, Illinois, 2006. ... Image File history File linksMetadata Download high resolution version (800x1200, 645 KB) Summary AL-8000, Alertronic High Powered Voice Siren, Civil defense, OFallon, Illinois, 2006. ... OFallon is a city located in St. ... It has been suggested that this article or section be merged with Function generator. ... For the British rock band of the same name, see Amplifier (band). ... Horn loudspeaker with a sealed box driver mounting A horn speaker is a loudspeaker which uses a horn to increase the overall efficiency of the driving element, typically a diaphragm driven by an electromagnet. ...

Typically the loudspeaker unit incorporates horn loading, which causes them to be similar in appearance to some supercharged electromechanical sirens.

Many of these loudspeakers incorporate a vertical array of horns, in order to achieve a practical yet effective high-power audio source with pattern control in the vertical plane. Each cell of the loudspeaker horn is driven by one or a multiple of compression drivers, which are typically purpose-built for siren applications.

One type of purpose-built compression driver for this type of loudspeaker handles 400 watts of electrical power and features an enormous magnetic structure with two donut-shaped magnet slugs stacked on top of each other to provide enormous flux.

For siren applications, high-fidelity sound is a secondary concern to high output, and siren drivers typically produce large amounts of distortion which would not be tolerable in an audio system where fidelity is important.

As with electromechanical sirens, there are both omni-directional and rotating categories, though Whelen Engineering produces sirens which oscillate through 360 degrees, rotating in one direction and then in the other to allow a hard-wired connection between the amplifiers and the siren drivers. Also, these sirens can be set to rotate any amount from 0 to 360 degrees, allowing sirens to broadcast only in (a) certain direction(s).

An example of a rotating electronic siren is the Whelen Engineering "Vortex" [8], American Signal Alertronic 4000[9] and Federal Signal Siratone 408, 612[10], & 816, whose design incorporates four vertically-arrayed loudspeaker cells exiting into a common manifold. This horn design accomplishes pattern control in the vertical plane and focuses the output into a high-penetration beam.

Examples of omni-directional electronic sirens are the Federal Signal "Modulator" series [11], Whelen Engineering WPS2700, WPS2800, and WPS2900 [12], and American Signal I~Force, in which compression drivers located in each cell exit into the center of the cell.

The contour of each cell forms the horn profile in this case, though other omni-directional sirens simply array directional re-entrant horn modules in all directions to produce a continuous coverage pattern, such as the ATI Sound Blaster series [13], and Federal Signal DSA series[14].

Defunct manufacturers

• CLM Industries - Maker of Toronto and Chicago warning sirens during the Cold War. One was most famously featured in the 1980 Chicago based film, The Blues Brothers, used as a vehicle mounted PA system. Toronto and Chicago have removed the majority of these sirens and, in the case of Chicago, they have been replaced by newer Federal Signal models, such as the 2001 and Modulator sirens.

• SoundMaster - was a siren company that manufactured sirens similar to Alerting Communications of America (ACA), which then became American Signal. SoundMaster formed after a member of staff for ACA (a lawyer)^{[citation needed]} found scrapped plans from ACA in a dumpster behind an ACA office^{[citation needed]}. SoundMaster started producing sirens based on these plans^{[citation needed]} and sold them to municipalities in Ohio^{[citation needed]}. The company was shut down after an ACA engineer noticed one of the scrapped sirens installed and traced the origins of the plans^{[citation needed]}. Today only a handful of SoundMaster sirens exist^{[citation needed]}.

For other uses, see Cold War (disambiguation). ... This article does not cite any references or sources. ...

Civil Defense sirens around the world

One of the many public address systems setup in Sydney, Australia as a result of APEC Australia 2007. Manufactured by Bosch.

Image File history File links Metadata Size of this preview: 552 × 599 pixelsFull resolution‎ (739 × 802 pixels, file size: 114 KB, MIME type: image/jpeg) One of the various outdoor public address systems installed at various locations around Sydneys Central Business District. ... Image File history File links Metadata Size of this preview: 552 × 599 pixelsFull resolution‎ (739 × 802 pixels, file size: 114 KB, MIME type: image/jpeg) One of the various outdoor public address systems installed at various locations around Sydneys Central Business District. ...

Major cities currently using outdoor Sirens

• Edmonton, Alberta, Canada
• Lethbridge, Alberta,Canada
• Vulcan, Alberta, Canada
• Halifax, Nova Scotia, Canada
• Helsinki, Finland
• London, United Kingdom
• Manila, Philippines
• Mexico City, Mexico
• Osaka, Japan
• Paris, France
• Singapore
• Sydney, Australia
• Taipei, Taiwan
• Tokyo, Japan
• Seoul, South Korea
• Wanganui, New Zealand
• Paraparaumu, New Zealand
• Zürich, Switzerland

A typical air-raid siren in Haifa, Israel. Sirens of this type are ubiquitous in Israeli towns and cities, and have been used for air raids and missile attacks in previous conflicts.

Edmonton is the capital of the Canadian province of Alberta, situated in the north central region of the province, an area with some of the most fertile farm land on the prairies. ... Lethbridge is a city in the province of Alberta, Canada. ... The town of Vulcan is located midway between the cities of Calgary and Lethbridge, in the southern part of Alberta, Canada. ... The City of Halifax (1841-1996) was the capital of the province of Nova Scotia, and the largest city in Atlantic Canada. ... Location of Helsinki in Northern Europe Coordinates: , Country Province Region Uusimaa Sub-region Helsinki Charter 1550 Capital city 1812 Government  - Mayor Jussi Pajunen Area  - Total 187. ... This article is about the capital of England and the United Kingdom. ... For other meanings of the word, see Manila (disambiguation). ... Mexico City (in Spanish: Ciudad de México, México, D.F. or simply México) is the capital city of Mexico. ... For other uses, see Osaka (disambiguation). ... This article is about the capital of France. ... This article is about the metropolitan area in Australia. ... Nickname: Coordinates: , Country Region City seat Xinyi District (信義區) Government  - Mayor Hau Lung-bin (KMT)1 E9 Area  - City 271. ... For other uses, see Tokyo (disambiguation). ... Short name Statistics Location map Map of location of Seoul. ... Wanganui   is an urban area and district on the west coast of the North Island of New Zealand. ... Paraparaumu Airport Paraparaumu is a town in the south-western North Island of New Zealand. ... For other uses of Zurich, see Zurich (disambiguation). ... Image File history File links Metadata Size of this preview: 305 × 599 pixelsFull resolution (1351 × 2653 pixel, file size: 680 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Metadata Size of this preview: 305 × 599 pixelsFull resolution (1351 × 2653 pixel, file size: 680 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Hebrew Arabic حَيْفَا Founded in 3rd century CE Government City District Haifa Population 267,000 1,039,000 (metropolitan area) Jurisdiction 63,666 dunams (63. ...

Australia

A series of around 40 electronic sirens making up a large scale public address system is installed in the Sydney central business district. While installed in the months preceding the 2007 APEC conference, they are designed as a permanent fixture. Aside from this, there are also usually small scale sirens, like the Model 5 or Model A which are found at fire stations for call-outs. These are also used at Sydney's beaches for shark alarms. When the alarm goes off, everyone must leave the water with no delay. Alarms are also used around prisons for break-outs.

Canada

In Canada a nation-wide network of sirens was established in the 1950's as to pre-warn urban populations of a possible Russian nuclear attack. The system was maintained until the 1970s when advancements in military technology reduced the Russian nuclear missile strike time from 3-5 hours to less than 15 mins. Sirens can still be found in most Canadian cities, all in various state of repair. In Toronto for instance, the network has been abandoned to the point that no level of Government will take responsibility for it's ownership[15].

Sirens have recently been built within 3 kilometers of the Darlington Nuclear Power Plant and the Pickering Nuclear Power Plant, in the Province of Ontario. (Both plants are within 30 kilometers/19 miles from each other.) These sirens will sound in the event of a nuclear emergency such as "A severe accident at either the Pickering or the Darlington Nuclear Station that could result in a release of radioactivity". [16]

France

In France the Emergency population warning network is called the "Réseau national d'alerte" (RNA). The system is inherited from the air-raid siren network (défense passive) developed before the World War II. It consists of about 4,500 electronic or electromechanical sirens placed all over France.^[2] Some emergency situations can reach an entire population. ...

The system is tested every month, the first Wednesday at 12 noon.

In small municipalities hosting a centre for fire-fighters first intervention, the siren is also sometimes calling volunteer fire-fighters when their intervention is required, but the signal is different, and the system is increasingly being replaced by pagers.

Israel

Air raid sirens used are typically sounded to warn of rocket attacks and other threats to the civilian population, and were used throughout the Israeli and Hezbollah conflicts. The "all-clear" signal is used three times yearly to denote a minute's silence on Israel's Holocaust memorial day and Day of Remembrance. Yom haShoah VeHagvura or Yom HaShoah (יום השואה yom ha-sho’āh, יום הזיכרון לשואה ולגבורה-Yom ha-zikaron la-Shoah vla-Gvura), or The Remembrance day of The Holocaust and the Heroism, takes place on the 27th day of Nisan, in the Hebrew calendar. ... Yom Hazikaron (Memorial Day, Hebrew: יום הזכרון לחללי מערכות ישראל ונפגעי פעולות האיבה, Israel Fallen Soldiers and Victims of Terrorism Remembrance Day) is an Israeli national holiday. ...

The Netherlands

Siren on a pole as used in the Netherlands.

The Netherlands tests its air raid sirens once a month, every first Monday at 12:00 pm. ^[3] Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (1536 × 2048 pixel, file size: 1. ... Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (1536 × 2048 pixel, file size: 1. ... Motto: Je Maintiendrai (Dutch: Ik zal handhaven, English: I Shall Uphold) Anthem: Wilhelmus van Nassouwe Capital Amsterdam1 Largest city Amsterdam Official language(s) Dutch2 Government Parliamentary democracy Constitutional monarchy  - Queen Beatrix  - Prime minister Jan Peter Balkenende Independence Eighty Years War   - Declared July 26, 1581   - Recognised January 30, 1648 (by Spain...

Switzerland

Switzerland currently has 7750 mobile and stationary civil defence sirens, which can alert 99% of the population^[4]. There are also 750 sirens located near dams^[4]. Every year, on the first Wednesday of February Switzerland's sirens are tested. During this test, general alert sirens as well as the sirens near dams are tested to see if they are in working order^[4]. The Population is informed of the test in the days prior to it by radio, television, teletext and newspapers^[4]. The siren tests do not require the population to take any special measures.

Swiss Alarm Signals

The tones of the different sirens is provided on the last page of all phone books as well as on the Internet .

• The general alert siren goes off when there is a possible threat to the population. Sirens for this alert have a regularly ascending and descending tone lasting a minute and repeated after a two-minute interval. The population is instructed to inform those around them to proceed inside. Once inside, people are instructed to listen to emergency broadcasts made by the DRS, RSR, RTSI and/or RTR^[4].

• Flood alerts consist of twelve low continuous tones each lasting 20 seconds. The flood alert is activated once the general siren is sounding. If heard by the population in danger zones (near dams, therefore) they must leave the danger area immediately or find shelter^[4].

United States

In the United States, sirens are usually used to warn of tornadoes and flash floods, as threats of military attacks on the United States are rare. They are usually also present in areas within a ten-mile radius of nuclear power plants. Many cities in the US and other countries around the world periodically sound their sirens as a test, either weekly or monthly or yearly at a day and hour set by each individual city. A nuclear power station. ...

Major U.S. cities using outdoor sirens

Note: Chicago is home to Federal Signal and Milwaukee is home to American Signal. Nickname: Location in Jefferson County in the state of Alabama Coordinates: , Country State Counties Jefferson, Shelby Incorporated December 19, 1871 Government  - Type Mayor - Council  - Mayor Bernard Kincaid (Current) Larry Langford (Mayor-Elect) Area  - City 151. ... Baltimore redirects here. ... Nickname: Motto: Urbs in Horto (Latin: City in a Garden), I Will Location in the Chicago metro area and Illinois Coordinates: , Country State Counties Cook, DuPage Settled 1770s Incorporated March 4, 1837 Government  - Mayor Richard M. Daley (D) Area  - City 234. ... Cincinnati redirects here. ... Nickname: Location in the state of Missouri Coordinates: Country United States State Missouri County Boone Government  - Mayor Darwin Hindman Area  - City  59 sq mi (138. ... Nickname: Location in the state of Ohio, USA Coordinates: , Country State Counties Franklin, Delaware, and Fairfield Government  - Mayor Michael B. Coleman (D) Area  - City  212. ... Dallas redirects here. ... Austin is the capital of the U.S. state of Texas and the seat of Travis County. ... Denver redirects here. ... Detroit redirects here. ... : Gem City : Birthplace of Aviation United States Ohio Montgomery 56. ... Nickname: Motto: Where the West Begins Location of Fort Worth in Tarrant County, Texas Coordinates: , Country State Counties Tarrant, Denton Government  - Mayor Michael J. Moncrief Area  - City 298. ... For the city and county of Honolulu, see City & County of Honolulu. ... Indianapolis redirects here. ... : Crossroads of the South : The city of Grace and Benevolence United States Mississippi Hinds, (very small portions in Madison and Rankin) 106. ... Nickname: Location in Jackson, Clay, Platte, and Cass Counties in the state of Missouri. ... Louisville redirects here. ... For other uses, see Memphis (disambiguation). ... For other uses, see Madison (disambiguation). ... For other places with the same name, see Milwaukee (disambiguation). ... Minneapolis redirects here. ... Nashville redirects here. ... Oakland redirects here. ... OKC redirects here. ... “Omaha” redirects here. ... Sacramento redirects here. ... San Francisco redirects here. ... Savannah redirects here. ... Nickname: Location in the state of Missouri Coordinates: , Country State County Independent City Government  - Mayor Francis G. Slay (D) Area  - City  66. ... St. ... St. ... State capitol building in Saint Paul Saint Paul is the capital and second-largest city of the state of Minnesota in the United States of America. ... This article is about the state capital of Kansas. ... Nickname: Location in the state of Oklahoma Coordinates: , Country State Counties Tulsa, Osage, Rogers Government  - Mayor Kathy Taylor (D) Area  - City 186. ... For other uses, see Wichita (disambiguation). ... Spartanburg is the largest city and the county seat of Spartanburg CountyGR6 in South Carolina, and is the second-largest city of the three primary cities in the Upstate region of South Carolina. ...

Other uses

Sirens have been used in a number of pieces of music for special effect including Eradication Instincts Defined by Dimmu Borgir, Ionization by Edgard Varèse, Fireman by Lil Wayne, In Memoriam by Robert Steadman, Danjer by O.G.C., Pulse Of The Maggots by Slipknot, Mr. Churchill Says by The Kinks, When You Smile by The Flaming Lips, War Pigs by Black Sabbath, and "Christmas at Ground Zero" by Weird Al Yankovic. For the geologic feature in Iceland, see Dimmuborgir. ... Ionization is the physical process of converting an atom or molecule into an ion by changing the difference between the number of protons and electrons. ... Edgard Victor Achille Charles Varèse (December 22, 1883 – November 6, 1965) was a French-born composer. ... Dwayne Michael Carter, Jr. ... In Memoriam A.H.H. is a long poem by the English poet Alfred, Lord Tennyson. ... Robert Steadman (born April 1, 1965) is a British composer of classical music who mostly works in a post-minimalist style but also writes lighter music, including musicals, and compositions for educational purposes. ... O.G.C. [Originoo Gunn Clappaz] are a Hip Hop group consisting of Starang Wondah [Gunn Clappa One], Louieville Sluggah [Gunn Clappa Two] and Top Dog [Gunn Clappa Three]. The group is mostly known through their membership in the Boot Camp Clik, along with Black Moon, Smif-N-Wessun and... Slipknot (sometimes typeset as SlipKnoT to fit their logo) is a Grammy winning American metal band from Des Moines, Iowa. ... Mr. ... The Kinks were an English rock group formed in 1963 by lead singer-songwriter Ray Davies, his brother, lead guitarist and vocalist Dave Davies, and bassist Pete Quaife. ... The Flaming Lips (formed in Oklahoma City, Oklahoma in 1983) are an American alternative rock band. ... War Pigs is an anti-war song by British heavy metal rockers Black Sabbath from their 1970 album, Paranoid. ... For other uses, see Black Sabbath (disambiguation). ... Nuclear fireball World War III is the name given to a hypothetical world war that would be fought after World War II. Most usages of the term include the use of weapons of mass destruction such as nuclear weapons. ... This article is about the musician. ...

This kind of Siren has also been featured in 'Silent Hill'. This article is about the video game franchise. ...

During the 2007 MLB season, the Baltimore Orioles uses an air raid siren whenever an Orioles player hits a home run. // The 2007 Major League Baseball season is the 107th since the American and National Leagues combined to form Major League Baseball. ... This article is about the contemporary American major league baseball team. ... Homerun redirects here. ...

References

External links

Wikimedia Commons has media related to:

Civil defense siren

• Air Raid Sirens(ARS) - Site featuring articles, walk-through and recordings; some dated, some timeless. Community Forum offers help and advice as well as common information, dates, specs, photos, recordings, videos, servicing tips and much more.
• Civil Defense Museum - Overview of sirens since their inception
• The Winning Side - Air Raid Sirens in Post-Cold War Los Angeles
• Los Angeles air raid sirens - Pictures of unused nuclear-era civil defense sirens still extant in Los Angeles, California
• The Siren Archive - Over 1,000 siren photographs coupled with a few recordings from around the world
• The World's loudest and largest sirens ever
• Video of Swiss annual siren test, YouTube
• "Tocsin B", Canada's dry run of it's Nuclear Warning System from 1961 (contains actual pre-recorded radio warnings)
• Toronto Star story about air raid sirens in Toronto.

Image File history File links Commons-logo. ...

Manufacturers

• American Signal Corp Makers of the T-128 and T-135 (loudest siren in production)
• ATI System Electronic sirens
• Hormann America Inc
• Hormann Warningsystems GmbH
• Klaxon Siren
• Sentry Sirens Mechanical sirens
• Warning Systems UK Emergency warning systems for Government, Industry and the Military
• Whelen Engineering Electronic sirens