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Four-minute warning
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.
The warning would be initiated by the detection of inbound missiles and aircraft targeted at the United Kingdom. Early in the Cold War, Jodrell Bank was used to detect and track incoming missiles, while continuing to be used for astronomical research.
Throughout the Cold War, there was a conflict between the Royal Air Force and the Home Office about who was in charge of the warning system. This was not for any practical or technical reason but more to do with who would be blamed if a false alarm were given or if an attack occurred without warning. By the 1980s, the warning was to be given on the orders of a Warning Officer from the Home Office's Warning and Monitoring Organisation stationed at RAF Booker near High Wycombe.
From the early 1960s, initial detection of attack would be provided primarily by the RAF BMEWS station at Fylingdales in North Yorkshire. There, powerful radar would track the inbound missiles and allow confirmation of targets. In later years the first indication of any imminent attack would be expected to come from infrared detectors aboard the United States Defense Support Program (DSP) satellites. BMEWS would still play an important role in tracking and confirming the destination of any launches.
The British government was not the main beneficiary of BMEWS, given that it would only receive what Solly Zuckerman described in 1960 as "no more than five minutes warning time" of an attack. The United States was the United Kingdom's most important military and technological partner, and its US-based Strategic Air Command would have thirty minutes warning from the Fylingdales station, whilst the RAF's own V bomber force would have about ten minutes. A 1977 Home Office manual for scientific advisers stated that, while "[n]o particular warning time can be guaranteed", a minimum of three minutes' warning was to be expected.
It was the responsibility of the United Kingdom Warning and Monitoring Organisation (UKWMO) at the United Kingdom Regional Air Operations Centre (UK RAOC) located at RAF Booker to alert the nation to an imminent air attack. Once an alert was initiated the national and local television and radio networks would break into transmissions and broadcast a warning (the warning message would originate from an emergency studio in BBC Broadcasting House in London). Simultaneously the national air raid siren system would be brought into service. A system, which used the same frequency on normal telephone lines as the peacetime speaking clock, was employed for this whereby a key switch activation alerted 250 national Carrier Control Points or CCPs present in police stations across the country. In turn the CCPs would, via a signal carried along ordinary phone lines, cause 7,000 powered sirens to start up. In rural areas, around 11,000 hand powered sirens would be operated by postmasters, rural police officers, or Royal Observer Corps personnel (even parish priests, publicans, magistrates, subpostmasters or private citizens could be involved in some remote rural areas).
The national warning system saw many changes over the years. During the 1960s and 1970s, much of the local authority civil defence planning in the United Kingdom became outdated, although the WB400/WB600 warning system was maintained and kept serviceable along with updating of ROC instrumentation and communications. The system's main problem was that many of the telephone lines it needed had to be manually switched in times of pre-war tension by Post Office telephone engineers. The links were not hardened against the effects of EMP. In the late 1970s and early 1980s heightened fears and tensions led to a resumption of contingency planning and the upgrading of many systems. The outdated WB400/WB600 systems were replaced with brand new WB1400 equipment, communications links were made permanent and hardened against EMP disruption.
The national siren system originating from World War II had a secondary role of "general warning", particularly for imminent flooding. Following the end of the Cold War, a telephone-based system was thought to be more appropriate for national warnings and less expensive to maintain.
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Four-minute warning AI simulator
(@Four-minute warning_simulator)
Four-minute warning
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.
The warning would be initiated by the detection of inbound missiles and aircraft targeted at the United Kingdom. Early in the Cold War, Jodrell Bank was used to detect and track incoming missiles, while continuing to be used for astronomical research.
Throughout the Cold War, there was a conflict between the Royal Air Force and the Home Office about who was in charge of the warning system. This was not for any practical or technical reason but more to do with who would be blamed if a false alarm were given or if an attack occurred without warning. By the 1980s, the warning was to be given on the orders of a Warning Officer from the Home Office's Warning and Monitoring Organisation stationed at RAF Booker near High Wycombe.
From the early 1960s, initial detection of attack would be provided primarily by the RAF BMEWS station at Fylingdales in North Yorkshire. There, powerful radar would track the inbound missiles and allow confirmation of targets. In later years the first indication of any imminent attack would be expected to come from infrared detectors aboard the United States Defense Support Program (DSP) satellites. BMEWS would still play an important role in tracking and confirming the destination of any launches.
The British government was not the main beneficiary of BMEWS, given that it would only receive what Solly Zuckerman described in 1960 as "no more than five minutes warning time" of an attack. The United States was the United Kingdom's most important military and technological partner, and its US-based Strategic Air Command would have thirty minutes warning from the Fylingdales station, whilst the RAF's own V bomber force would have about ten minutes. A 1977 Home Office manual for scientific advisers stated that, while "[n]o particular warning time can be guaranteed", a minimum of three minutes' warning was to be expected.
It was the responsibility of the United Kingdom Warning and Monitoring Organisation (UKWMO) at the United Kingdom Regional Air Operations Centre (UK RAOC) located at RAF Booker to alert the nation to an imminent air attack. Once an alert was initiated the national and local television and radio networks would break into transmissions and broadcast a warning (the warning message would originate from an emergency studio in BBC Broadcasting House in London). Simultaneously the national air raid siren system would be brought into service. A system, which used the same frequency on normal telephone lines as the peacetime speaking clock, was employed for this whereby a key switch activation alerted 250 national Carrier Control Points or CCPs present in police stations across the country. In turn the CCPs would, via a signal carried along ordinary phone lines, cause 7,000 powered sirens to start up. In rural areas, around 11,000 hand powered sirens would be operated by postmasters, rural police officers, or Royal Observer Corps personnel (even parish priests, publicans, magistrates, subpostmasters or private citizens could be involved in some remote rural areas).
The national warning system saw many changes over the years. During the 1960s and 1970s, much of the local authority civil defence planning in the United Kingdom became outdated, although the WB400/WB600 warning system was maintained and kept serviceable along with updating of ROC instrumentation and communications. The system's main problem was that many of the telephone lines it needed had to be manually switched in times of pre-war tension by Post Office telephone engineers. The links were not hardened against the effects of EMP. In the late 1970s and early 1980s heightened fears and tensions led to a resumption of contingency planning and the upgrading of many systems. The outdated WB400/WB600 systems were replaced with brand new WB1400 equipment, communications links were made permanent and hardened against EMP disruption.
The national siren system originating from World War II had a secondary role of "general warning", particularly for imminent flooding. Following the end of the Cold War, a telephone-based system was thought to be more appropriate for national warnings and less expensive to maintain.