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Square Leg

1980 British civil defence exercise

Square Leg

1980 British civil defence exercise

'Square Leg' target plot

Square Leg was a British government home defence Command Post and field exercise which was held from 11 to 25 September 1980 and which tested the Transition to War and Home Defence roles of the Ministry of Defence and British government. Part of the exercise involved a mock nuclear attack on Britain; the exercise scenario of 150 nuclear weapons striking Britain, with "almost all" of these weapons having a yield ranging from 500 kilotons to 3 megatons and a resulting total yield of 280.5 megatons, with underwater bursts also being depicted. Furthermore, the scenario was altered from official assessments as these were highly classified and many participants did not have the appropriate clearance to see them.

Partial bomb plots were released for England and Wales and for Scotland, but not for Northern Ireland. While official casualty figures were not provided, Stan Openshaw and Philip Steadman produced an independent estimate of 29 million deaths (53 percent of the population) and 7 million seriously injured (12 percent), with short-term survivors numbering 19 million (35 percent).

Square Leg was criticised for a number of reasons: the weapons used were exclusively in the high-yield megaton range, with an average of 1.5 Mt per bomb, but a realistic attack based on known Soviet capabilities would have seen mixed weapons yields, including many missile-based warheads in the low-hundred-kiloton range. Also, no targets in Inner London were attacked (for example, Whitehall, the centre of British government), though collateral damage from strikes on Outer London targets and on Potters Bar and Ongar meant that much of the Inner London area was still destroyed; towns such as Eastbourne were hit for no obvious reason. All government and military bunkers were assumed to have survived for exercise purposes, although Kelvedon Hatch Sub-Regional Headquarters had difficulty in establishing regional control. The United Kingdom Warning and Monitoring Organisation was not a "live" participant, with the strike data it would have provided instead being pre-recorded and played into the exercise as it proceeded, an aspect that was criticised by participants after the exercise.

The Lothian Regional Council refused to participate in Square Leg, and the exercise came under journalistic scrutiny after its details were leaked to the press, but otherwise, despite providing a "major boost" to the nuclear disarmament movement, it was not met with significant opposition in the way that the later Hard Rock exercise would be.

Timeline of main events and civil and armed forces actions

Transition to War

The following table shows the hypothetical pre-strike event list drawn from the national Main Event List for Square Leg, testing the Transition to War stage.

DateEvent
January 1980last1=MacGregorfirst1=Janetitle=Operation Square Leg: Did You Survive 1980?url=https://ia801909.us.archive.org/17/items/subterranea-5/Subterranea%205.pdf#page=21magazine=Subterraneapublisher=Subterranea Britannicaaccess-date=4 April 2025pages=18–20date=September 2004issn=1741-8917via=the Internet Archive}}
April - August 1980Soviet Union demands that Norway and Denmark withdraw from NATO, sparking diplomatic tension that continues into August. Public reaction is calm as the situation is believed to be just another deterioration in East-West relations.
By early August 1980NATO commanders declare a state of vigilance in anticipation of war. Reserve forces are mobilised and civil defence planning is initiated at a covert level.
Prior to and including 15 AugustPlanning becomes more overt in the continued absence of a diplomatic solution. Major urban centres clear their hospitals of patients and all but a few staff members in order to make way for anticipated casualties, prompting protests from patients and their families, and from local authorities who find themselves facing increased pressure on care home places.
16 AugustFuel rationing imposed, leading to queues at petrol stations and police needing to be drafted in to prevent hoarding.
27 AugustGovernment requests preparations to be made to remove art treasures.
31 AugustIndustrial unrest and large-scale activity by extreme left- and right-wing parties. Resentment is directed at the heavier than usual police presence and the police's role in controlling subversives and potential subversives. Multiple arrests made under emergency powers. Arson attacks on industrial sites, supermarkets, etc. Police require military assistance to quell some of the unrest; they manage to do so without shots being fired.
1 SeptemberConsiderable cross-Channel movement into the UK by expatriate families on a self-evacuation basis.
7 SeptemberPrime Minister addresses nation via TV and radio.
9 SeptemberSecretary of State authorises power of direction over British Airways and national shipping.
11 SeptemberPrime Minister again addresses nation.
12 SeptemberProtect and Survive instructions, which were already available at libraries and HMSO in pamphlet form, are issued through the media. Those who intend to follow instructions begin doing so.
13 SeptemberPrime Minister speaks to nation for a third time.
15 SeptemberGeneral Alert and war declared. Fighting breaks out on continent. Conventional bombing on defence related targets in UK. Public reaction to bombing is mixed - those living in high-rise flats and in areas generally thought to be obvious targets leave home quickly.
17 SeptemberFighting on continent escalates.
19 SeptemberAttack Warning Red]] 11.55 am. Nuclear strike starts at 12.01 pm and ends at 12.10 pm. Strike mainly hits military and communications targets, though civilian areas are also targeted.

Survival

The following table of Square Leg's 'survival' period, detailing the events that occurred in the first two weeks following the attack, is extracted from the Warwickshire County War Diary.

DateEvent
20 SeptemberDaily food requirements - 680,700 rations. Eighteen thousand people (in refugee camps) suffering third-degree burns. Isolated reports of refugees leaving West Midlands area.
22 SeptemberCasualty aid points swamped. Hospitals and improvised hospitals full.
23 SeptemberCommence mass advice to achieve public order.
24 SeptemberEstablish additional casualty aid points close to existing where possible. Commit to home nursing casualties who will probably die. Commence grave-digging operations.
25 SeptemberIdentify rationing levels of food and water. Identify additional rationing requirements of workers. Flow of refugees from the West Midlands is indicated; 31,000 to North Warwickshire, 12,000 to South Warwickshire.
27 SeptemberCasualty figures Rugby area is indicated 30,000 plus estimate, Nuneaton area 17,000 plus. Large numbers of persons suffering first stages of radiation sickness. Arrange for establishment of decontamination units. Consider variations to law - liaise with police.
28 SeptemberEstimate 100,000 plus refugees coming from West Midlands - most injured/shocked/irradiated. Consider disinfection in Rugby/Coventry area to avert disease. Liaise with military for aircraft for spraying. Control of refugees in the west of the county impossible at this date.
29 SeptemberNumbers increasing at casualty aid points, priority being given to savable under-thirties. Anticipate refugee figures to be 200,000 plus. Further requests to Sub-Regional HQ for additional food; SRHQ directive received - conserve food.
30 SeptemberArrange collection of food from Buffer Depots. Liaise with police and military for convoy guards. Food to be held and guarded in district stores. Deaths becoming a serious problem, liaise with transport and works for speedier removal of bodies from casualty aid points. Advise public on action to be taken re looting - particularly theft of food. Call for volunteers to assist with transport and works tasks.
1 OctoberNotification from SRHQ; twenty-five per cent of food requirements for refugees to come from local Buffer Depots. Police Support Units established and deployed to areas where refugees are known to be located. Consider establishment of interim police controls in known trouble areas.
2 OctoberFeeding to commence at 1800 hrs. Calorific content of meals will be six hundred + one pint of water (non-workers), 800 + two pints of water (workers). Meals provided for infant feeding totally inadequate, request additional supplies.

Police and military tasks during this and the Recovery period were set out as follows:

  • "Maintenance of law and order - greatest problem [in] urban areas"
  • "Control of selfish and disgruntled minorities"
  • "Support and protect special courts"
  • "Execution of sentences" (military only)
  • "Key points protection and reinforcement"
  • "Protection of convoys"
  • "Guards for controls"
  • "Personal protection for VIPs"
  • "Subjugation and elimination of hostile elements"
  • "Control of weapons"
  • "Bomb disposal" (military only)
  • "Supervision and control of operations involving the use of explosives, e.g. demolitions"
  • "Guards on internment areas"
  • "Assisting in control at communal feeding centres"
  • "Enforcement of controls to prevent the spread of disease"
  • "Manning any pre-planned pattern of military stations and posts"
  • "Maintenance and control of Essential Service Routes"
  • "Control of movement"
  • Tasks regarding the training of new personnel "to compensate for wastage"
  • Reconnaissance tasks
  • Advisory tasks

Recovery

The 'recovery' period reports are drawn from the Gloucestershire County War Diary's log of requests for military support.

DateRequest to military staffResponse
3 OctoberRequest for air reconnaissance at Little Rissington food depot.No response.
Provide armed troops to assist police at ten locations on M5 Motorway.Thirty men deployed.
Provide coils of barbed wire.Barbed wire requested.
Provide armed troops to assist troops at Gloucester to:(a) Twenty-five troops sent.
Provide ambulances, trained first aid personnel and medical supplies.No ambulances, trained first aid personnel or medical supplies available. Some vehicles and drivers only.
Provide armed troops to assist police with law and order problems at Cirencester, Cinderford, Lydney and Newnham.Thirty armed men made available for Cirencester. Due to radiation hazard, (it is) not considered effective to send armed parties into other areas at this time.
Provide armed guards to secure [Ministry of Agriculture, Fisheries and Food] warehouse.County Military HQ requested [Armed Forces HQ] 7 to provide assistance from east of county due to radiation levels.
4 OctoberProvide assistance to police at Gloucester to deal with law and order problem.Fifteen men from Hare Lane detailed for this task.
Secure and guard a food warehouse at Cirencester.Twenty armed men despatched from Innsworth at 0930 hrs.
Provide guards at twelve food supply and cooking centres throughout the country (sic, most likely meant to be county instead). Provide escorts on ten food supply vehicles.Five armed guards provided at each location. Two armed guards provided for each vehicle.
Assist police to prevent hostile crowd gaining access to Gloucester District Wartime HQ.Twenty armed men made available.
Assist police at GCHQ (Government Communications Headquarters in Cheltenham) which is under attack by looters and refugees.Two mechanized platoons despatched at 1400 hrs.
Accommodate five thousand homeless at RAF Innsworth.Cannot accommodate at RAF Innsworth but could take four thousand two hundred at RAF Quedgely (sic). Vehicles available at Aschurch (sic), but no drivers or fuel.
Provide hygiene and sanitation teams and equipment at Cheltenham. Provide rodenticides and disinfectants.Unable to assist.
Provide security patrols and barbed wire at Special Rest Centre at Stroud for suspected disease-carrying refugees.Two platoons despatched to Stroud. No stocks of barbed wire available.
Provide assistance to Ministry of Agriculture officers who have been prevented by hostile crowd from arranging the despatch of food from a market garden.1630hrs. Wessex helicopter and twelve soldiers sent to scene.

References

  • Doomsday, Britain after Nuclear Attack, Stan Openshaw, Philip Steadman and Owen Greene, Basil Blackwell, 1983
  • War Plan UK, Duncan Campbell,
  • The National Archives, FCO 46/2446 to 46/2448, HO 322/950

Footnotes

References

  1. (2015). "War Plan UK".
  2. [[South Yorkshire County Council]]. (1980). "Emergency Planning Report on Exercise Square Leg}} Cited in {{cite web".
  3. (3 October 1980). "World War III: an exclusive preview".
  4. was felt to be reasonably realistic, but the post-exercise report stated that a total strike in excess of 1,000 megatons would be likely. An increased ratio of [[ground burst]]s to [[air burst]]s was depicted to provide all the regional [[CBRN defense
  5. (September 1984). "South Yorkshire and Nuclear War".
  6. (2015). "War Plan UK".
  7. (6 March 1981). "Scotland's nuclear targets".
  8. (6 March 1981). "Scotland's nuclear targets".
  9. (3 October 1980). "Square Leg caught out".
  10. ''Doomsday, Britain after Nuclear Attack'', p. 105
  11. (December 1980). "Square Leg".
  12. (2015). "War Plan UK".
  13. (2015). "War Plan UK".
  14. (September 2004). "Operation Square Leg: Did You Survive 1980?". [[Subterranea Britannica]].
  15. (2015). "War Plan UK".
  16. (2015). "War Plan UK".
  17. (2015). "War Plan UK".
  18. (2015). "War Plan UK".
  19. (2015). "War Plan UK".
  20. (2015). "War Plan UK".
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