All clear is the signal, generally given by an air raid siren, which indicates that an air raid or other hazard has finished and that it is safe for civilians to leave their shelters; it is commonly used in radios as well.
All clear is the signal, generally given by an air raid siren, which indicates that an air raid or other hazard has finished and that it is safe for civilians to leave their shelters; it is commonly used in radios as well.
During the First World War, the Metropolitan Police introduced their first air raid warning system in London in 1917, which consisted of police officers detonating maroons (a type of loud firework) and the "all clear" was sounded by Boy Scout buglers. [1]
Immediately before the Second World War, a network of sirens had been established in towns across the United Kingdom; the "alert" was given by a rising and falling tone and the "all clear" by a continuous tone. [2] The sirens remained in place during the Cold War but instead of being the responsibility of local police forces, the alarms were activated by the United Kingdom Warning and Monitoring Organisation. Following an air raid, the "all clear" would only be sounded if no nuclear weapons had been used, or when any nuclear fallout was deemed by the Royal Observer Corps to have reached safe levels, which might have been up to two weeks later. The system was discontinued in 1992. [3]
The following is a list of countries that use All Clear on sirens:
Civil defense or civil protection is an effort to protect the citizens of a state from human-made and natural disasters. It uses the principles of emergency management: prevention, mitigation, preparation, response, or emergency evacuation and recovery. Programs of this sort were initially discussed at least as early as the 1920s and were implemented in some countries during the 1930s as the threat of war and aerial bombardment grew. Civil-defense structures became widespread after authorities recognised the threats posed by nuclear weapons.
A civil defense siren is a siren used to provide an emergency population warning to the general population of approaching danger. Initially designed to warn city dwellers of air raids during World War II, they were later used to warn of nuclear attack and natural disasters, such as tornadoes. The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies.
Air Raid Precautions (ARP) refers to a number of organisations and guidelines in the United Kingdom dedicated to the protection of civilians from the danger of air raids. Government consideration for air raid precautions increased in the 1920s and 30s, with the Raid Wardens' Service set up in 1937 to report on bombing incidents. Every local council was responsible for organising ARP wardens, messengers, ambulance drivers, rescue parties, and liaison with police and fire brigades.
A siren is a loud noise-making device. There are two general types: mechanical and electronic. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire engines.
The four-minute warning was a public alert system conceived by the British Government during the Cold War and operated between 1953 and 1992. The name derived from the approximate length of time from the point at which a Soviet nuclear missile attack against the United Kingdom could be confirmed and the impact of those missiles on their targets.
An emergency population warning, or public warning system is a method where by local, regional, or national authorities can contact or notify members of the public to warn them of an impending emergency. These warnings may be necessary for a number of reasons, including:
The United Kingdom Warning and Monitoring Organisation (UKWMO) was a British civilian organisation operating to provide UK military and civilian authorities with data on nuclear explosions and forecasts of fallout across the country in the event of nuclear war.
Emergency vehicle equipment is any equipment fitted to, or carried by, an emergency vehicle, other than the equipment that a standard non-emergency vehicle is fitted with.
The Coventry Blitz was a series of bombing raids that took place on the British city of Coventry. The city was bombed many times during the Second World War by the German Air Force (Luftwaffe). The most devastating of these attacks occurred on the evening of 14 November 1940 and continued into the morning of 15 November.
Federal Signal Modulators are electronic warning devices produced by Federal Signal Corporation that are used to alert the public about tornadoes, severe weather, earthquakes, fires, lahars, tsunamis, or any other disaster. They are identified mostly by their distinctive stacked "flying saucer" design. The Modulator II is sold based on the more compact chassis of the siren compared to the original Modulators.
The Wartime Broadcasting Service is a service of the BBC that is intended to broadcast in the United Kingdom either after a nuclear attack or if conventional bombing destroyed regular BBC facilities in a conventional war. It is unclear if the Wartime Broadcasting Service is still operational as plans are kept mainly secret with the BBC and government officials. According to an article by the BBC, recordings of a nuclear attack warning are still re-recorded and kept up to date periodically.
Civil defense in Israel deals with a variety of military and terrorist threats to the civilian population, which have included concealed bombs such as suicide bombings and car bombs, projectiles such as missiles, rockets and mortar shells, and hijacking of aircraft, buses and buildings. Threats have originated in all countries and territories bordering Israel, as well as Iraq, and an Israeli civil airliner was attacked with missiles in Kenya. Perceived threats that have not materialized to date include sustained interruption of the economy, nuclear attack from Iran, and chemical or biological attack from Iraq or elsewhere.
In civil defense sirens, the ATI High-Power Speaker Station (HPSS) is an electronic outdoor warning siren manufactured by Acoustic Technology, Inc (ATI) that is used to alert citizens of air raids, and natural disasters.
The Public Warning System (PWS) is a network of civil defense sirens installed by the Singapore Civil Defence Force on over 2,000 strategic points in Singapore to warn Singaporeans of impending dangers, air raids and atomic bomb blasts. Thus far, the siren network has only been used for occasional public awareness drills, monthly noon chimes and for commemorating the island's Total Defence (February 15) and Civil Defence Days (September 15). It was also used to mark a minute's silence nationwide for the passing of former prime minister Lee Kuan Yew on the evening of 23 March 2015 and on 1 and 9 August 2020 to mark the first National Day at home.
The siren suit is a one-piece garment for the whole body which can easily be put on or taken off, originally designed for use on the way to, and in, air-raid shelters. The suit solved the problems of warmth and modesty encountered when seeking shelter during nighttime air raids in the United Kingdom during World War II. It was roomy and could be put on over night clothes quickly when an imminent air raid was announced by the sirens.
A firefighting apparatus or firefighting appliance describes any vehicle that has been customized for use during firefighting operations. These vehicles are highly customized depending on their needs and the duty they will be performing. These duties can include firefighting, technical rescue, and emergency medical services.
The United Kingdom's mobile phone alert system is a public population warning system that uses Cell Broadcast technology. The warning system is intended for use in major incidents such as flooding or terror attacks. The Emergency Alert System was launched on 19 March 2023, and tested on a nationwide basis for the first time on 23 April 2023.
Canadian Line Materials LTD. (CLM) was a Canadian siren manufacturing company which built civil defense sirens. These sirens were built and installed all over Canada to warn residents and military about incoming nuclear attacks from the USSR during the Cold War.
Ukraine Siren Alerts (UASA) is a siren alert electronic system created by Israeli student Bernard 'Boaz' Moerdler. The system automatically alerts users of sirens in Ukraine using data from municipal and cities who post alerts on their website and is based on Israel's Red Color system, which alerts users when a siren is sounded anywhere in Israel. Initially launched on Twitter, the system has since expanded to Telegram and Facebook channels alongside releasing their new website which includes SMS and email alerts.
The Thunderbolt is a mechanical outdoor warning siren that was manufactured by Federal Signal Corporation from 1951 until its production ended in 1991. It is a unidirectional, rotating siren with a large square-shaped horn, and can come in various colors, usually yellow, by request.
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