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British Nuclear Programmes
Immediately after World War II, in August 1945, the new Labor government in
Britain organized a secret Cabinet committee to establish nuclear policy. On 8
January 1947 this committee of six Ministers (headed by P.M. Attlee) decided to
proceed with development and acquisition of atomic weapons, a fact that was not
disclosed at all until 12 May 1948, when an oblique reference was made to atomic
weapon development in parliamentary discussions. The first plutonium production reactor went critical at Windscale (now Sellafield) in October 1950. The plutonium plant began operation on 25 February 1952, and produced the first plutonium metal 35 days later. Due to the small size and high population density of Britain no suitable sites for atmospheric weapons tests existed. Britain thus sought sites in other countries to test its weapons, finally settling on the Monte Bello Islands in Australia. On 15 September 1952 the plutonium pit for the first British nuclear device, code named Hurricane, left England.
Hurricane
This was the first British nuclear test. The device tested was a plutonium implosion bomb similar to the Fat Man, but improved by using a levitated pit. The bomb used plutonium produced at Windscale (now Sellafield) with a low Pu-240 content since hurried production led to short irradiation times. In fact Windscale could not quite meet the August 1 deadline for manufacturing the core and the device also used some Canadian-supplied plutonium. To test the effects of a ship-smuggled bomb (a threat of great concern to the British at the time), Hurricane was exploded inside the hull of the HMS Plym (1450 ton frigate) which was anchored in 40 feet of water 400 yards off shore. The explosion occured 2.7 m below the water line, and left a saucer-shaped crater on the seabed 20 feet deep and 1,000 feet across.
Operation Totem: 1953This series was intended to develop greater knowledge of fission weapons. The initial test (Hurricane) had been hurriedly carried out and was poorly instrumented. Plutonium with a much higher Pu-240 content (and thus lower cost) was now being produced by Calder Hall and needed to be evaluated in a nuclear test.
Second British test. The yield was greater than expected.
Third British test. The absolute maximum and minimum yield estimates were 10 and 0.25 Kt respectively, with 2-3 Kt most likely.
Operation Mosaic: 1956The primary purpose of this test series was to conduct research to support thermonuclear weapons development.
First British test using fusion fuel (as a physics experiment, not a weapon test). Fusion yield was negligible.
This was the highest yield test ever conducted in Australia. Since the test yield broke an assurance made personally by PM Anthony Eden of the UK to PM Robert Menzies of Australia that the yield would not exceed 2.5 time that of Hurricane (thus about 62 Kt), the true yield was concealed until 1984. Mosaic G2 was a test of fusion-boosted weapon system, perhaps similar to the Soviet Sloika ("Layer Cake") or American Alarm Clock designs. It incorporated lithium-6 deuteride, and had a uranium tamper. The yield was larger than expected.
Operation Buffalo: 1956Maralinga Test Range, AustraliaThis was the first test series at the Maralinga Test Range in South Australia (bordering Western Australia). It would reused in two other test series. Buffalo combined atomic (fission) weapons development with weapons effects testing for military purposes.
This was a test of the Red Beard tactical bomb, a plutonium implosion weapon (expected yield 16 Kt).
This was a test of the Blue Danube bomb equipped with a low yield Mark I enriched uranium core. The test was exploded on the surface rather than a tower to collect ground shock and cratering data. The bomb was placed in a shallow pit so the center of the nuclear reaction would be exactly at the surface. It produced a 160 ft wide crater, 40 ft deep.
This was Britain's first air drop test. It tested a Blue Danube bomb dropped from an RAF Valiant B1 bomber (WZ366 of squadron no. 49). This Service operational test was originally scheduled for a 40 Kt core, but concerns about contamination caused a substitution with a low yield bomb core.
This was another test of the Red Beard light weight tactical bomb with some fusion fuel included as a fusion physics experiment to supplement to Mosaic data.
Operation GrappleThe British test program to develop a hydrogen bomb.
Dropped by a Valiant B1 bomber (XD818 of Squadron No. 49) piloted by Wing Commander K. Hubbard. Detonated after 52 sec of free fall. This was Britain's first test of a radiation implosion thermonuclear bomb design. The device, named Green Granite Small, weighed 10,000 lb and used a modified Red Beard primary (called "Tom") and a lead-encased lithium deuteride secondary (called "Dick"). Most of the yield was from the secondary, providing evidence of successful radiation implosion, but the yield was far below the predicted value (about 1 megaton was expected).
Dropped by a Valiant bomber (XD824) piloted by Squadron Leader Barney Millett. Detonated after 52 sec of free fall. This was Britain's first truly successful thermonuclear bomb test. The test seems to have been hastily arranged. The bomber squadron was only notified about the test in September, followed by four weeks of intensive training in preparation. Documents indicate this test had not even been contemplated prior to the spring Grapple shots. The probable reason for this was that it was a rushed redesign following the disappointing Short Granite and Purple Granite shots, spurred on by British fears of an imminent test ban. Only one device, designated Round C, was tested with a yield of 1.8 Mt. This was Britian's first megaton-class explosion, showing that the UK had achieved mastery of H-bomb design.
Dropped by a Valiant bomber (XD825) piloted by Squadron Leader Bob Bates. Detonated 53 seconds after release, only 245 yards off target. This was Britain's fourth test of a radiation implosion thermonuclear bomb, and the second successful high yield test.
Dropped by a Valiant bomber (XD822) piloted by Bill Bailey from 45,000 ft, missed target point by a mere 95 yards. The first British use of blind radar bombing with a nuclear device. This was Britain's fifth test of a radiation implosion thermonuclear bomb. It was the first of Britain's two highest yield tests.
Dropped by a Valiant bomber (XD827) piloted by Flight Lieutenant Tiff O'Connor. This was the second of Britain's two highest yield tests.
Christmas Island
Joint US - UK TestingAfter the 1957-1958 test series the United Kingdom ceased conducting its own independent nuclear tests. The reason for this was that it was no longer necessary. After the UK had demonstrated that it could develop thermonuclear weapons, the US adopted it as a strategic partner in deterring the Soviet Union. All subsequent UK nuclear weapons are based on US designs, which were made available to Britain. Once nuclear testing resumed in 1961, the US and UK also began conducting joint tests at hte NTS (Nevada test Site) in Nevada, eventually conducting a total of 28 (counting four zero-yield plutonium dispersal safety experiments). The first was the Pampas shot during Operation Nougat, 1 March 1962 (yield 9.5 Kt). See summary table below for complete listing of these tests. After the Grapple tests, the British lent Christmas island to the US in 1962 for the Dominic series of 25 tests. British Testing SummaryUK Atmospheric Nuclear Tests in Australia and at Christmas Island 1952-58
Joint US-UK TestsLegend:NAFR= Nellis Air Force Range (Nevada); NTS= Nevada Test Site
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Hurricane (26 K)
Hurricane - 0.1 seconds (20 K)
Hurricane - 1 seconds (23 K)
Hurricane - 5 seconds (19 K)
Totem/T1 - First view (10 K)
Totem/T1 - Second view (20 K)
Totem/T2 (21 K)
Mosaic/G1 (32 K)
Mosaic G2 - View 1 (33 K)
Mosaic G2 - View 2 (16 K)
Mosaic G2 - View 3 (15 K)
One Tree 1 (29 K)
One Tree 2 (26 K)
One Tree 3 (21 K)
One Tree 4 (18 K)
Marcoo 1 (27 K)
Marcoo 2 (23 K)
Marcoo 3 (15 K)
Round 3, Kite (27 K)
Breakaway (50 K)
Breakaway - Second View (20 K)
Grapple 1/Short Granite (60 K)
Grapple X/Round C (60 K)
Grapple X/Round C (84 K)
Grapple Y
at Detonation
Grapple Z/Flagpole 1 (68 K)
Grapple Z/Halliard 1 (68 K)
