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.

Early in the Cold War, Jodrell Bank was used to detect and track incoming missiles, while continuing to be used for astronomical research.

[1] 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.

[2] From the early 1960s, initial detection of attack would be provided primarily by the RAF BMEWS station at Fylingdales in North Yorkshire.

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.

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 5 minutes warning time" of an attack.

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.

During the 1960s and 1970s, much of the local authority civil defence planning in the United Kingdom became outdated, although the WB400/WB600 warning system was maintained and kept serviceable along with updating of ROC instrumentation and communications.

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The outdated WB400/WB600 systems were replaced with brand new WB1400 equipment, communications links were made permanent and hardened against EMP disruption.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.

The British government cited the increasing use of double-glazed windows (which make sirens harder to hear) and the reduced likelihood of air attack as reasons to eliminate the system in most parts of the country.

Some coastal and river areas have retained and regularly test the sirens as part of the flood warning defences.

The first single of the UK rap crew Gunshot, from 1990, was entitled "Battle Creek Brawl (4 Minute Warning)".

The narrator, Michael Aspel, says it could even be two-and-a-half to three minutes between issuing the warning and impact on a target, or less than 30 seconds for a SLBM attack.

The film adaptation of Raymond Briggs's satirical and blackly comic cartoon strip, When the Wind Blows, has the warning message as part of the script, which triggers arguing between Jim and Hilda Bloggs.

The four-minute warning had become the inspiration for many jokes and sketches in comedy programmes in Britain, in the same way that the Emergency Broadcast System had in the United States (see nuclear weapons in popular culture).

In one episode of Only Fools and Horses, "The Russians Are Coming," Delboy and Rodney Trotter sell fallout shelter kits and have an attack drill.