Britain’s Nuclear Deterrent Development – Part 10

Britain’s Nuclear Deterrent Development – Part 10

On 16 July 1945, with the support of Britain, the United States detonated the world’s first atomic weapon. In August 1949, the USSR successfully tested their first nuclear device. With the success of Operation Hurricane in October 1952, Britain had become the world’s third nuclear power. 

The Atomic Energy Act of 1946 (McMahon Act) stipulated that the US would not share information concerning atomic weapons. Having tested their first atomic weapon, Britain expected a return to collaboration with the United States. However, across the pond the US had been developing a much more powerful weapon – the hydrogen bomb. 

On 1 November 1952, less than a month after Britain’s successful detonation of an atomic bomb, the US tested its first hydrogen bomb. The technological advantage this gave the US, and a series of spy scandals in 1950 and 1951, led to them having no desire to share their nuclear secrets. 

In 1951, the US had conducted Operation Greenhouse. It was the fifth of their nuclear tests and tested principles that led to them building the hydrogen bomb. The idea of the operation was to reduce the size and weight of the weapon, and reduce the amount of fissile material needed for nuclear weapons, while increasing the destructive power. The ‘George’ device was a boosted nuclear (atomic) bomb rather than a thermonuclear (hydrogen) one. The test validated the principles which would be used during Operation Ivy for the first full-scale thermonuclear bomb test, codenamed Ivy Mike. 

Ivy Mike Sausage device
A view of the “Sausage” device casing, with its instrumentation and cryogenic equipment attached. The long pipes were for measurement purposes; their function was to transmit the first radiation from the “primary” and “secondary” stages (known as “Teller light”) to instruments just as the device was detonated, before being destroyed in the explosion. Note man seated lower right for scale. 

Operation Ivy took place on 1 November 1952, on Elugelab Island, part of the Enewetak Atoll in the Marshall Islands. The Ivy Mike device was a prototype design and not a deliverable weapon. It stood over 20ft high and weighed at least 64 tonnes. It could not have been dropped from even the largest of aircraft.  

Its explosion yielded energy equivalent to 10.4 megatons of TNT, which was over 450 times the power of the bomb dropped onto Nagasaki. The explosion obliterated Elugelab, leaving an underwater crater 6,240ft (1.9km) wide and 164ft (50m) deep where the island had once been. 

Not to be outdone, on 12 August 1953, the Soviet Union exploded its first hydrogen device which was labelled ‘Joe-4’ by America. The measured yield was 400 kilotons, but the Soviets were unable to scale the design into the megaton range. They would need to work on a more powerful version.

Despite the inability to improve the Joe-4 device, the detonation was still used by Soviet diplomats as leverage. The Soviets claimed that they also had a hydrogen bomb, but unlike the US weapon they could deploy theirs by air. This created obvious concern within the US government and military.

Prime Minister, Winston Churchill’s reaction was:

“we were now as far from the age of the atomic bomb as the atomic bomb itself from the bow and arrow.”

If Britain was ever to fall victim to a Soviet hydrogen bomb bombardment, Churchill feared that:

“all we hold dear, ourselves, our families and our treasures” would be immolated and “even if some of us temporarily survive in some deep cellar under mounds of flaming and contaminated rubble, there will be nothing left to do but to take a pill to end it all.”

While Britain may have been behind in the race to develop a hydrogen bomb, the means to deliver atomic and hydrogen bombs was very much on target. The V-Force aircraft designs, development and production were well underway. In September 1953, the Valiant Mk2 was on display at the Farnborough Airshow.

In the same year Air News showed footage of the world’s first delta-winged bomber – the Vulcan.

The third and final V-bomber was to be the Handley Page Victor. While the Victor had taken its first flight in December 1952, it wouldn’t be part of an operational RAF bomber squadron until 1958. The aircraft did appear at 1955’s Farnborough Airshow, along with the still secret Vulcan, and the Valiant.

Blue Danube was to be the first operational British nuclear weapon and the RAF V-force was to use it as their primary armament. At the time of planning, the first hydrogen bomb had not been detonated. The operational requirement for the bomb – OR.1001 – was issued in August 1946 and the V-bomber bomb-bays were sized to carry Blue Danube, the smallest size nuclear bomb that was possible to be designed given the technology of the day.  

A technician inspecting the Blue Danube Bomb
A technician inspecting the Blue Danube bomb

When the first Blue Danube atomic bombs were delivered to RAF Wittering’s Bomber Command Armaments School, in November 1953, the RAF had no bombers capable of carrying them. Sir William Penney noted that:

“the RAF has handled aircraft for a long time and can fly Valiants as soon as they come off the production line. But the Royal Air Force has not yet handled atomic weapons, therefore, we must get some bombs to the RAF at the earliest possible moment, so that the handling and servicing can be practised and fully worked out.”

After Britain’s successful Operation Hurricane test, more British nuclear weapons tests were carried out over the following years, each leading Britain closer to a hydrogen weapon. 

October 1953 | Operation Totem | Two tests

These were atmospheric tests with the main purpose of determining acceptable limits on the amount of plutonium-240 which could be present in a bomb. Plutonium was now being produced by the Calder Hall power reactors with a much higher Pu-240 content and needed to be evaluated in a nuclear test. 

The tests conclusively answered the questions about plutonium-240. The Totem tests also taught British scientists a great deal about how to conduct trials and measure the fallout of the explosion. Monitoring stations were to be established across Australia for any further tests. A few days after the conclusion of these tests, the British government formally made a request to the Australian government for a permanent testing site.  

Prime Minister, Winston Churchill, believed in a ‘nuclear deterrence’ and the concept of Mutually Assured Destruction (MAD).  The concept of MAD had been discussed in literature for nearly a century before the invention of nuclear weapons. One of the earliest references comes from the English author Wilkie Collins. At the time of the Franco-Prussian War in 1870, he wrote:

“I begin to believe in only one civilising influence—the discovery one of these days of a destructive agent so terrible that War shall mean annihilation and men’s fears will force them to keep the peace.”

It was addressing parliament in November 1953, when Churchill said he was looking forward to a time when:

“the advance of destructive weapons enables everyone to kill everybody else” because then, “nobody will want to kill anyone at all.”

In June 1954, Churchill recommended that Britain must build its own hydrogen bomb, and in August Australia agreed that Maralinga, a remote area in South Australia, could be used as a permanent test site. A formal Memorandum of Arrangements for use of Maralinga specified that:

  • the site would be available for ten years
  • no thermonuclear  (hydrogen bomb) tests would be carried out
  • the British Government would be liable for all claims of death or injury to people or damage to property as a result of the tests, except those to British Government personnel
  • Australian concurrence would be required before any test could be carried out
  • the Australian authorities would be kept fully informed.  


Maralinga would not be ready for the next trial – Operation Mosaic – which would be held in the Montebello Islands, off the coast of north-west Australia, in May 1956. 

Meanwhile, the United States had been developing a deployable version of their hydrogen bomb and carried out tests in March 1954, at Bikini Atoll, Marshall Islands. The tests were codenamed Operation Castle. Castle Bravo was the first of the series and the device used was named “Shrimp”. The device weighed approximately 23,500lbs, was based on the Teller-Ulam thermonuclear weapon design and was readily adaptable for delivery by an aircraft. On 1 March, at 6:45am local time, Shrimp became the most powerful nuclear device detonated by the US. The explosion yielded 15 megatons of TNT – 1,000 times more than the weapon dropped on Hiroshima! This was 2.5 times the predicted amount, as there were unforeseen additional reactions in the device. A mushroom cloud 7km wide was formed seconds after the detonation and eventually reached a height of 130,000ft. The explosion left a crater on the ocean floor that measured 6,500ft wide and 250ft deep. The explosion led to radioactive contamination of the atolls. The more particulate and gaseous fallout from the explosion spread around the world. 

The US Joint Task Force 7 (JTF-7) was caught unprepared. The intense thermal blast ignited a fire 37km away on the island of Eneu. The fallout contaminated the entire Atoll Islands and could not be approached by JTF-7 for 24 hours after the test, and even then, exposure times to the site were limited. 28 US servicemen were affected, along with 236 inhabitants of the islands who were not evacuated until three days after the explosion and suffered radiation sickness. 23 Japanese fishermen on the tuna fishing boat Daigo Fukuryū Maru (Lucky Dragon 5) were also contaminated by the heavy fallout. The crew suffered acute radiation syndrome for a number of weeks after the Bravo test.  

Inspection of Atomic tunas
Inspection of tuna with a Geiger counter before sale at a fishmongers on 31 March 1954 

The ‘International Churchill Society’ website reports:

aside from the enormity of the blast, Bravo gave Churchill something else to worry about: nuclear fall-out, airborne radioactive “death clouds.” The danger from fall-out was acute for Britain. As Churchill reminded Eisenhower, the current generation of Soviet bombers had the operational range to reach the UK but not the USA. Hence, if another war came, it would be Britain and Western Europe, not America, that faced the prospect of total devastation.

Churchill had been uneasy about Dwight D. Eisenhower becoming Truman’s successor to the US Presidency in 1953. After Stalin died on 5 March 1953, his successors were quick to employ the language of détente – the easing of hostility or strained relations, especially between countries. Churchill had sought a summit meeting with the Soviets, but Eisenhower refused out of fear that the Soviets would use it for propaganda. Churchill had decided that Eisenhower as president was “both weak and stupid”. The Prime Minister believed that the US President did not fully comprehend the danger posed by the hydrogen bomb. Churchill met Eisenhower on a number of occasions but could not get a summit meeting agreed. 

On 1 March 1955, Winston Churchill made a speech to the House of Commons about nuclear weapons, defence through deterrents and the Cold War.  


It was to be his last great speech in Parliament. On 5 April 1955, Churchill retired and Anthony Eden took over as Prime Minister.  

Eventually it was the Soviets who proposed a four-power summit (Britain, the United States, France and the Soviet Union). The meeting didn’t take place until 18 July 1955 – three months after Churchill had retired. The stated mission of the 1955 Geneva Summit was to reduce international tensions. The Cold War had a major impact on the topics debated during the summit. As tensions were on the rise, the Cold War leaders thought it would be a good idea to unite under a common cause for peace in Geneva. The world leaders discussed issues on security, armaments, German unification, and stronger East-West relationships. The conference marked an era of renewed optimism in Cold War relationships, but this was to be disrupted by the Suez Crisis in 1956.  

Eden was British Prime Minister for less than two years when he resigned through ill health on 9 January 1957. This was shortly after his controversial handling of the Suez Crisis, which began in October 1956. The Conservative Party had no formal mechanism for selecting a new leader at that time. It was expected that Eden’s deputy, Rab Butler, would be chosen, but the Queen appointed Harold Macmillan as Prime Minister after taking advice from Winston Churchill and the Marquess of Salisbury, who had asked each cabinet member for their opinion. The mass majority of the cabinet opted for Macmillan. 

In 1954, the Atomic Energy Research Establishment (AERE) was incorporated into the newly formed United Kingdom Atomic Energy Authority (UKAEA).  The scientists at the UKAEA’s Atomic Weapons Establishment (AWE) at Aldermaston in Berkshire included William Penney, William Cook, Ken Allen, Samuel Curran, Henry Hulme, Bryan Taylor and John Ward. The British had in-depth knowledge of atomic bombs as many of the British scientists helped to develop the weapons at the Los Alamos Laboratory during the war. They did not know how to build a hydrogen bomb, but some British scientists, including Egon Bretscher who was the Head of the Nuclear Physics Division of the AERE, had attended the conference in Los Alamos on the hydrogen bomb, or ‘Super’ as it was known then, in April 1946. Also, Chadwick had written a secret report on it in May 1946. The British team set to work on three designs to build and test: Orange Herald, a large boosted fission weapon; Green Bamboo, an interim thermonuclear design; and Green Granite, a true thermonuclear design

On 8 February 1955, the first production Vickers Valiant, WP199, was delivered to the RAF and in March 1956, the first Avro Vulcan, XA889, underwent acceptance trials for the aircraft type’s Certificate of Airworthiness at the Aeroplane and Armament Experimental Establishment (A&AEE). The Vulcan was cleared for entry into RAF service on 29 May 1956. Meanwhile tests continued on the development of the weapon which the aircraft would carry. 

May and June 1956 | Operation Mosaic | Two tests

The purpose of this pair of tests was to explore increasing the yield of British nuclear weapons as part of the development towards a hydrogen bomb. 

At the end of the countdown, there was a blinding electric blue light, of such an intensity I had not seen before or ever since. I pressed my hands hard to my eyes, then, realised my hands were covering my eyes. This terrific light power, or rays, were actually passing through the tarpaulin, through the towel, and through my head and body, for what seemed ten to twelve seconds, it may have been longer. After that, the pressure wave, which gave a feeling such as when one is deep underwater. This was then followed by a sort of vacuum suction wave, to give a feeling of one’s whole body billowing out like a balloon. 

Observer, Mosaic G1 at Monte Bello, 16 May 1956. 

September and October 1956 | Operation Buffalo | Four tests

This was the first test series to be conducted at Maralinga, and the largest tests ever held in Australia. On 27 September, the first test of Operation Buffalo took place. The test was codenamed One Tree and tested the newly developed Red Beard weapon.

Blue Danube, was large and cumbersome. It was 7.3 metres (24ft) long, 1.5 metres (5ft) wide and weighed 4,500 kg (10,000lb). In November 1953, Operational Requirement, OR.1127, was issued for a smaller, lighter weapon with similar yield that could be carried by tactical aircraft. Red Beard was the result.

Red Beard Bomb On Trolley By Source Fair use
Red Beard nuclear bomb on its bomb trolley. The man standing on the left indicates scale.

Red Beard measured 3.66 metres (12ft) long, 0.71 metres (2.3ft) in diameter, and weighed approximately 794kg (1,750lb)

One Tree was a tower mounted test of the Red Beard tactical nuclear bomb. The yield was an estimated 16 kilotons of TNT. The cloud rose to 11,400 metres (37,500ft) which was much higher than expected. A short while after the detonation a Canberra bomber flew through the cloud to collect samples. 

On 4 October 1956, round two of the tests was carried out, codenamed Marcoo. This was a ground test of the Blue Danube bomb equipped with a low yield Mark I enriched uranium core. The predicted yield was just under 2 kilotons. The test was exploded on the surface to collect ground shock and cratering data. The bomb was placed in a shallow pit so the centre of the nuclear reaction would be exactly at the surface. The explosion produced a 160ft wide crater and 40ft deep, with a 58-inch lip and a yield of 1.5 kilotons. 

On 11 October, in test three, Valiant, WZ366 became the first RAF aircraft to drop a live atomic bomb. The test was codenamed Kite. Windscreen blinds were fitted to protect the crew from the intense flash of light that the nuclear detonation would cause.

A Blue Danube Mark 1 bomb drops away from a Vickers Valiant B.1 bomber. Ministry of Defense
A Blue Danube bomb drops away from a Vickers Valiant B.1 bomber. © Ministry of Defence

A Blue Danube bomb was dropped by the Valiant. It was the most difficult of the four tests, because if the radar fuses failed and the bomb detonated on impact with the ground, it would cause severe nuclear fallout. The original plan was to use a 40-kiloton core, but this was substituted with a low yield core that produced 3 kilotons of TNT. The pilot, Squadron Leader Edwin Flavell, and the bomb aimer, Flight Lieutenant Eric Stacey, were awarded the Air Force Cross for their part in the tests. 

The flight crew of Valiant B.1 WZ366. Squadron Leader E.J.G. Flavell is at the far left. The Telegraph
The flight crew of Valiant B.1 WZ366. Squadron Leader E.J.G. Flavell is at the far left. © The Telegraph

The fourth and final test of Operation Buffalo was on 22 October, codenamed Breakaway. This was another test of the Red Beard nuclear bomb conducted from a 30 metre tower. This test included a fusion physics experiment to supplement the Mosaic data.  

Britain’s next tests would begin in May 1957, at Malden Island in the Pacific Ocean. The tests would be codenamed Operation Grapple. Grapple tests would continue into 1958 also taking place at Christmas Island in the Pacific Oceans. They would be Britain’s first hydrogen bomb tests. 


More Articles