Operation Castle

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Nuclear test
Operation Castle
Castle Romeo
Castle Romeo
information
nation United StatesUnited States United States
Test location Bikini Atoll
Period February – May 1954
Number of tests 6th
Test type Above-ground tests
Weapon type Hydrogen bombs
Max. Explosive force 15 m
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Previous test Operation Upshot Knothole
Next test Operation Teapot

Operation Castle was an American nuclear weapons test series that was carried out mainly on Bikini Atoll in the Pacific in 1954 . The Bravo and Yankee tests are the most powerful nuclear weapons tests the United States has ever conducted to date. 'Bravo' had almost three times as much explosive power as expected as a result of incorrect calculations at Los Alamos National Laboratory .

The Bravo and Romeo tests have become the epitome of the hydrogen bomb . The many pictures that were taken during the operation contributed to this.

The individual tests of the Castle series

Castle Union explosion
bomb Date / Time
( GMT )
place Ignition level Test type Explosive force (prediction) Remarks
Bravo March 1, 1954
6:45 p.m.
Artificial island about one kilometer from Namu Island in Bikini Atoll 2 meters
(7 feet)
Surface explosion 15 MT
(6 MT)
Strongest nuclear thermonuclear explosion in the United States
Romeo March 27, 1954
6:30 p.m.
In the crater of the Bravo test 4 meters
(14 feet)
Barge 11 MT
(4 MT)
Romeo was the stress test for the Mark 17/24 bomb. For the test, a 20-ton construction called the "Runt-I-Device" was used. Romeo was the first test on a floating pontoon (or lighter) in the Pacific, this type of test was later used in all high-level nuclear weapons tests to protect the islands in the Bikini and Eniwetok Atolls.
Koon April 6, 1954
6:20 pm
Bikini Atoll, Eninman Island 3 meters
(9.6 feet)
Surface explosion 110 kT
(1 MT)
Weakest test of the Castle operation, a so-called "Fizzle". Only the primary stage ignited, the experimental design of the Morgenstern second stage led to the premature heating of the fusion stage due to the neutron flux from the fission reaction, which therefore did not ignite.
union April 25, 1954
6:10 p.m.
Bikini Atoll 4 meters
(13 feet)
Barge 6.9 MT
(4 MT)
An alarm clock device was used for the Castle Union explosion. This bomb was a prototype that contained a specially enriched uranium mixture. The explosive device had a diameter of 156 cm, a length of 384 cm and a weight of 13.85 t. The detonation tore a crater 92 m in diameter and 28 m deep into the atoll.
Yankee May 4, 1954
6:10 p.m.
Bikini Atoll 4 meters
(14 feet)
Barge 13.5 MT
(9.5 MT)
Second largest American nuclear test; Castle Yankee I with a Jughead design was deleted after the Castle Bravo test, instead the test was carried out with a Runt II warhead ( Castle Yankee II ). The test used a bomb similar to Romeo, with the difference that lithium was enriched in the nuclear fuel and not untreated, as in Romeo. This change resulted in a 61 percent increase in explosive power.
Nectar May 13, 1954
6:20 p.m.
Eniwetok Atoll, in the crater of the Ivy Mike Test 4 meters
(14 feet)
Barge 1.69 MT
(1.8 MT)
Test of a lightweight design, the so-called zombie device. The bomb was 87 cm in diameter, 282 cm in length and weighed 2.59 tons. In comparison, the “ Little Boy ” bomb dropped on Hiroshima weighed 4 tons (but only 15 kilotons of explosive force).

The echo test was canceled after the result of the Koon test was established.

Castle Bravo

Reactions of the lithium and hydrogen isotopes. Planned (expected) and actual (got) reaction of 7 Li
Castle Bravo explosion
Castle Bravo . The silhouette was included for size comparison.

The most powerful American thermonuclear weapon was tested, detonating with an explosive force of about 15 megatons of TNT equivalent, making it almost 2.5 times as powerful as its designers predicted.

The explosive device tested was the first nuclear weapon to use the solid fusion fuel lithium deuteride . The lithium was enriched in the rarer isotope Li-6. The explosive device was named Shrimp . Before the test, the strength of the explosion was estimated to be around half too low at 4 to 8 MT; the designers apparently overlooked the fact that not only Li-6, but also the other natural lithium isotope Li-7 reacts with the fast neutrons from the fusion and generates tritium for further fusions. The mushroom cloud was 15 km high after one minute, 40 km after six minutes and over 100 km in diameter. The flash of light could still be seen 400 kilometers away. The crater that the bomb tore into the underground of the atoll was about 2 km in diameter.

236 residents of Rongelap Island were irradiated in this, the largest ever nuclear weapon test ever detonated on the atoll , many of whom became radiation sick or were severely burned. The 23-person crew of the Japanese fishing boat Glücklicher Drache V , which is 140 kilometers away , was heavily contaminated, which caused diplomatic resentment with Japan. One crew member (radio operator) died as a result of radiation sickness, and the United States paid the victims compensation.

Web links

Commons : Operation Castle  - collection of pictures, videos and audio files

Footnotes

  1. Eric Schlosser (2013): Command and Control: The nuclear arsenals of the USA and the illusion of security , CH Beck, ISBN 978-3-406-65595-1 , pp. 145 f. ( online )
  2. Schwabe, Klaus .: World power and world order: American foreign policy from 1898 to the present: a century of history . Schöningh, Paderborn 2006, ISBN 978-3-506-74783-9 .
  3. Nuclear Test Personnel Review (NTPR) Program, DNA 6035F (PDF)
  4. a b Michael Light: 100 Suns. 2003.
  5. As part of the restructuring, the Nectar test was postponed by a month after the Bravo test (planned test on April 5, 1954) and, instead of in the crater of the Union test in Bikini Atoll, carried out in Eniwetok Atoll; see. Defense Nuclear Agency, US Fact Sheet: OPERATION CASTLE (1981 Dec 01), NV0402490
  6. Kenneth W. Ford: Building the H Bomb. A personal history. World Scienzific, Singapore 2015, ISBN 978-981-4632-07-2 , p. 184.
  7. Bauernfeind, Ingo: Radioactive to all eternity - The fate of the Prinz Eugen . ES Mittler & Sohn, Hamburg / Berlin / Bonn 2011, ISBN 978-3-8132-0928-0 , p. 105 .

Coordinates: 11 ° 41 ′ 50 ″  N , 165 ° 16 ′ 19 ″  E