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.
The Emergency Broadcast System (EBS), sometimes called the Emergency Action Notification System (EANS), was an emergency warning system used in the United States. It was the most commonly used, along with the Emergency Override system. It replaced the previous CONELRAD system and was used from 1963 to 1997, at which point it was replaced by the Emergency Alert System.
CONELRAD was a method of emergency broadcasting to the public of the United States in the event of enemy attack during the Cold War. It was intended to allow continuous broadcast of civil defense information to the public using radio stations, while rapidly switching the transmitter stations to make the broadcasts unsuitable for Soviet bombers that might attempt to home in on the signals.
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.
A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary (theft) or property damage, as well as against intruders. Examples include personal systems, neighborhood security alerts, car alarms, and prison alarms.
A police car is a ground vehicle used by police and law enforcement for transportation during patrols and responses to calls for service. A type of emergency vehicle, police cars are used by police officers to patrol a beat, quickly reach incident scenes, and transport and temporarily detain suspects, all while establishing a police presence and providing visible crime deterrence.
Ground-controlled interception (GCI) is an air defence tactic whereby one or more radar stations or other observational stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War I by the London Air Defence Area organization, which became the Royal Air Force's Dowding system in World War II, the first national-scale system. The Luftwaffe introduced similar systems during the war, but most other combatants did not suffer the same threat of air attack and did not develop complex systems like these until the Cold War era.
An emergency population warning is a method where by local, regional, or national authorities can contact 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.
A tell-tale, sometimes called an idiot light or warning light, is an indicator of malfunction or operation of a system, indicated by a binary (on/off) illuminated light, symbol or text legend.
Transition to war (TTW) is a North Atlantic Treaty Organization (NATO) military term referring to a period of international tension during which government and society move to an open war footing. The period after this is considered to be war, conventional or otherwise, but the term TTW found its origins in the peak of the Cold War as a key NATO concept within the tripwire escalation of the DEFCON status. This could include the suspension of peacetime services, closing motorways to all but military traffic and the internment of subversives without charge or trial. The Federal Emergency Management Agency would declare this period as Increased Readiness in a move to expedite Civil Defense training, among other things in order to prepare civil authorities for a nuclear attack, and to an extent is similar to Transition to War.
Emergency vehicle equipment is used in the United Kingdom to indicate urgent journeys by an emergency service. This usage is colloquially known as "blues and twos", which refers to the blue lights and the two-tone siren once commonplace. A call-out requiring the use of lights and sirens is often colloquially known as a "blue light run".
Emergency service response codes are predefined systems used by emergency services to describe the priority and response assigned to calls for service. Response codes vary from country to country, jurisdiction to jurisdiction, and even agency to agency, with different methods used to categorize responses to reported events.
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.
The Mount Rainier Volcano Lahar Warning System consists of two separate components, operating in tandem: Acoustic Flow Monitors (AFM) and the All Hazard Alert Broadcast (AHAB) sirens. The AFM system was developed by the United States Geological Survey (USGS) in 1998 and is now maintained by Pierce County Emergency Management. The purpose of the warning system is to assist in the evacuation of residents in the river valleys around Mount Rainier, a volcano in Washington, in the event of a lahar. Pierce County works in partnership with the USGS, the Pacific Northwest Seismic Network (PNSN), Washington Military Department's Emergency Management Division, and South Sound 9-1-1 to monitor and operate the system.
The National Emergency Alarm Repeater (NEAR) was a civilian emergency warning device in the United States. It was a 2–3" (5–7.5 cm) square box designed to plug into a standard power outlet to receive a special signal sent over the electric power transmission lines. Research and testing for the NEAR program was developed in 1956 during the Cold War to supplement the existing siren warning systems and radio broadcasts in the event of a nuclear attack. The advent of the radio Emergency Broadcast System rendered NEAR obsolete, although a severe disadvantage inherent in the Emergency Broadcast System was that it required a television or radio to be turned on for a household to receive the emergency alarm, whereas NEAR did not. Despite this advantage, upon the introduction of the Emergency Broadcast System, stockpiled NEAR repeaters were destroyed by their respective manufacturers.
Level crossing signals are the electronic warning devices for road vehicles at railroad level crossings.
There are around 6,000 level crossings in the United Kingdom, of which about 1,500 are public highway crossings. This number is gradually being reduced as the risk of accidents at level crossings is considered high. The director of the UK Railway Inspectorate commented in 2004 that "the use of level crossings contributes the greatest potential for catastrophic risk on the railways." The creation of new level crossings on the national network is banned, with bridges and tunnels being the more favoured options. The cost of making significant reductions, other than by simply closing the crossings, is substantial; some commentators argue that the money could be better spent. Some 5,000 crossings are user-worked crossings or footpaths with very low usage. The removal of crossings can improve train performance and lower accident rates, as some crossings have low rail speed limits enforced on them to protect road users. In fact, between 1845 and 1933, there was a 4 miles per hour (6.4 km/h) speed limit on level crossings of turnpike roads adjacent to stations for lines whose authorising act of Parliament had been consolidated in the Railways Clauses Consolidation Act 1845 although this limit was at least sometimes disregarded.
