Civil defense siren

Federal Signal took advantage of this design and created their Thunderbolt Siren Series, utilizing Sutorbilt Roots Blowers of different varieties and outputs.

[citation needed] Electronic sirens may be mechanically rotated to cover a wide area, or may have transducers facing in all directions to make an omnidirectional pattern.

Individuals must go to shelters or their homes, lock doors and windows, take appropriate protective actions, and listen through the radio and television for instructions of civil defense.

They sound-off during the memorial of Atatürk's death on November 10 at 9:05 AM and often sound off for common emergencies such as Earthquakes, Tsunamis, Tornadoes, Chemical plant issues or incoming enemy attack.

On 2 June every year, the day of Hristo Botev and demised ones for the liberation and independence of Bulgaria is commemorated with a two-minute signal, different from the usual tone.

The sirens are mainly electronic ones (German made type ECN units or other high powered speaker systems on top of public buildings).

[citation needed] In Germany, the Warnämter ('warning authorities') were closed in the 1990s after the threat of the Cold War was over, since the ability to alert the public was then considered unnecessary.

In the 2000s, it was realized that the ability to warn the public is not only necessary in cases of war, but also in events like natural disasters, chemical or nuclear accidents, or terrorist attacks.

The electric sirens were controlled via phone lines and were operated from a central location, such as a city hall, fire station, post office, or local military base or outpost.

In the mid 2000s, the MoLaRi System was built around factories that work with hazardous materials, to warn surrounding areas in case of emergency or risk to public health or safety.

By order of the MPVO headquarters, the duty officer of the Central station of the radio network interrupted the broadcast of the program, turned on an electric player with a record of the alarm text.

The municipalities of Muta, Vuzenica, Podvelka, Radlje ob Dravi, Brežice, Krško and Sevnica use a 100-second-long wailing signal (named Neposredna nevarnost poplavnega vala) (consisting of four-second bursts separated by four seconds of silence) for the immediate danger of flash floods, used in case of overflow or collapse of a hydroelectric dam.

[citation needed] The Swedish alarm system uses outdoor sirens in addition to information transmitted through radio and television and sent by text messages and mobile apps.

The most common cause of general alarms is fire, specially in situations that involve industries, landfills, and other facilities containing dangerous substances which can create hazardous smoke.

[56] Audio sample of signal "Important public announcement" recorded in Stockholm, 6 March 2017ⓘ Switzerland currently has 8,500 mobile and stationary civil defense sirens, which can alert 99% of the population.

[citation needed] Every village, town, and city in the United Kingdom used to have a network of dual-tone sirens to warn of incoming air raids during World War II.

In 2008, a review of the current and future role of flood warning sirens was undertaken by Norfolk County Council, after plans to retire them were halted following concerns from nearby residents.

[77] Emergency planners had proposed to use a new warning system that would contact residents by telephone; however, this was abandoned due to technical limitations and local media and other communication methods are used instead.

Following severe flooding in Upper Calder Valley in June 2000, the Environment Agency replaced its network of sirens, with eight being placed around Walsden, Todmorden, Hebden Bridge and Mytholmroyd.

In November 2010, 36 flood warning sirens in Essex, including nine on Canvey, were retired following concerns from the county council that the system was "no longer fit for purpose".

[86] In June 2016, the West London Mental Health Trust, who manages the hospital, proposed decommissioning the sirens altogether and replacing them with social media alerts through websites such as Twitter.

In Canada, a nationwide network of Canadian Line Materials sirens was established in the 1950s to warn urban populations of a possible Soviet nuclear attack.

In the dry areas of the American West, residents may be required to shut off outdoor water systems to ensure adequate pressure at fire hydrants upon hearing the signal.

Some communities, particularly in New England and northern California, make use of coded blasts over a diaphone or air horn for fire signals, reserving the use of sirens for more serious situations.

This is typically a one-second burst of sound to verify the proper operation of the siren without causing a significant number of people to interpret the test as an actual alert.

In Pierce County, Washington there is a system of sirens set up along the Puyallup and Carbon River valleys to warn residents of volcanic eruptions and lahars (giant mudslides) from Mt.

[102] Sirens in the United States have been replaced by NOAA Weather Radios for advance warnings about future severe storms whenever people are inside cars or buildings.

In Victoria, many Country Fire Authority stations have sirens installed that are used to summon volunteers to an emergency callout, as well as consequently alerting the local community of brigade activity.

[110] In the years following the tsunamis of the Indian Ocean earthquake in 2004, Meerkat electronic sirens were installed in all populated areas of the west coast lower than 10 metres.

Morocco, like many other countries, has civil defense sirens installed in several cities and towns such as Casablanca, Oujda, Asilah, M'diq, Chefchaouen, and Qalaat Sraghna.

An HSS TWS 295 Siren (license-built Whelen WPS-2805) in Saudi Arabia
There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year on the first Wednesday in February. [ 1 ] Sound sample
Federal Signal Model 5 in Ballston Spa, New York , U.S.
An ACA Allertor 125 in Alert and Attack modes (video)
An older and damaged 3T22 at a fire station in Sandy, Oregon, that has now been restored and hung from the ceiling of the entrance lobby
A Hormann HLS F-71 Pneumatic air-raid siren in Haifa , Israel. Sirens of this type are common in Israeli towns and cities, and until 2012 [ 4 ] were used to warn against air raids and missile attacks.
A SoCal Edison Model 120 illuminated by a spotlight in the night sky in 2003. They were manufactured in-house by SoCal Edison and were installed in 1982 for use with the San Onofre Nuclear Generating Station Community Alert Siren System. The blower is located in the middle just above the mounting plate hidden within the mesh bird screen between the frame support structure for the horns.
American Signal AL-8000 in O'Fallon, Illinois , US
One of the various outdoor public address systems to warn the public of terrorism, installed at various locations around Sydney's Central Business District
An electronic ECN3000 siren in Kfar Hess , Israel
Siren in Israel, during missile attack, October 2024
TWS-295 siren for warning system, manufactured by HSS Engineering
A complete set of air raid alarms
A typical siren found on police stations in Taiwan, seen with loudspeakers around it. Either the yellow mechanical siren or the surrounding electronic sirens are in service.
An example of a Bosai Musen electronic siren. Note the left one has an unusal design and has the UNI-PEX branding, and the right one has a reflex horn design and has the TOA logo on the front. Both are capable of playing music at certain times of day and broadcasting voice announcements.
An example of the most common Bosai Musen types in Japan. Note the one on the left has a common reflex horn design, while the right one has an unusual speaker design. Both are made by TOA, a Japanese company.
An example of a Bosai Musen electronic siren playing a version of the Yuyake Koyake Japanese folk song as an end of day signal. Note that the horns are made by UNI-PEX and painted green.
A public warning system siren in Singapore
A HSS Engineering TWS-295 (Whelen WPS 2805) electronic siren
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Federal Signal Modulator 2008 : Netherlands Electronic Air Raid Siren
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There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year on the first Wednesday in February. [ 1 ]
Sound of the general-alarm signal
Sound of the water-alarm signal
A Second World War-era Gents air raid siren, originally sited at RAF Uxbridge in Greater London . Unlike other Gents air raid sirens, this is a 10/12/15 tritone siren which gives off a unique warning tone.
Flood warning sirens, like this one in Magdalen in Norfolk, UK, are common along the River Great Ouse , which is prone to flooding.
Federal Signal Model SD-10
Federal Signal Model 500AT
Federal Signal Model 2001
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A Grifco 777 Siren at Empire Bay Rural Fire Station
A Grifco 888 Siren at Penrith Fire Station, New South Wales, Australia
This electronic siren is to warn the communities of bushfire and fire callout. They are being set up at the mountains of Queensland, Australia.
This electronic siren is to warn the communities of bushfire and fire callout. They are being set up at the mountains of Queensland, Australia.
Bushfire warning sirens in Mount glorious, Queensland, Australia
Bushfire warning sirens in Mount glorious, Queensland, Australia