Blue Danube (nuclear weapon)
Blue Danube was the first operational British
nuclear weapon. It also went by a variety of other names, including
Smallboy, the
Mk.1 Atom Bomb,
Special Bomb and
OR.1001, a reference to the Operational Requirement it was built to fill. The RAF
V bomber force was initially meant to use Blue Danube as their primary armament at a time when the first
hydrogen bomb had not been detonated, and the British military planners still believed that an atomic war could be fought and won using atomic bombs of similar yield to the
Hiroshima bomb. For that reason the stockpile planned was for up to 800 bombs with
yields of approx. 10-12
kilotons. V bomber bomb bays were sized to carry Blue Danube, the smallest-size nuclear bomb that was possible to design given the technology of the day (1947) when their plans were formulated.
Blue Danube was based on
Hurricane, the first British
fission device (which was not designed nor employed as a weapon), tested in 1952. Blue Danube added a ballistically shaped casing to the existing
Hurricane physics package, with four flip-out fins to ensure a stable ballistic trajectory from the planned release height of 50,000 ft. It initially used a
plutonium core, but all service versions were modified to use a composite plutonium/
U-235 core and a version was also tested with a uranium-only core. The Service chiefs insisted on a yield of between 10-12 kT for two reasons. Firstly to minimise usage of scarce and expensive fissile material, and secondly to minimise the risk of predetonation, a phenomenon then little understood, and the primary reason for using a composite core of concentric shells of plutonium and U-235. Almost all modern fission devices use a composite core. Although there were many plans for versions with higher yields, some up to 40 kT, none came to fruition, largely because of the scarcity of fissile materials, and there is no evidence that any were seriously contemplated.
The first Blue Danube was delivered to stockpile at
RAF Wittering in November 1953 athough there were no aircraft equipped to carry it until the following year.
No. 1321 Flight RAF was established at RAF Wittering in April 1954 as a
Vickers Valiant unit to integrate the Blue Danube nuclear weapon into RAF service. Declassified archives show that a total number of 58 were produced before production shifted in 1958 to the smaller and more capable
Red Beard weapon which could accept the Blue Danube fissile core, and could be carried by much smaller aircraft. It seems unlikely that all 58 Blue Danube weapons were operational at any given time. Blue Danube was retired in 1962.
Major deficiencies with Blue Danube included the use of unreliable
lead acid accumulators to supply power to the firing circuits and
radar altimeters. Later weapons used the more reliable
ram-air turbine-generators or
thermal batteries. Blue Danube was not really engineered as a weapon equipped to withstand the rigours of Service life. It was really a scientific experiment on a gigantic scale, that needed to be re-engineered to meet Service requirements. That re-engineered weapon became Red Beard. A similar account could be written of the first U.S. atomic bomb,
Fat Man, which was quickly re-engineered after
World War II.
*Moore. R; A Glossary of Nuclear Weapons. pub: Prospero, Journal of the British Rocketry Oral History Project (BROHP) Spring 2004.
*University of Southampton, Mountbatten Centre for International Studies at website
*http://www.mcis.soton.ac.uk/Site_Files/pdf/nuclear_history/glossary.pdf
*Various declassified official files at The National Archives, London.
