Over 21,000 soldiers took part in the ground exercise Desert Rock V in conjunction with the Grable shot.[1]Grable was a 280mm Artillery Fired Atomic Projectile (AFAP) shell fired from the "Atomic Cannon" and was viewed by a number of high-ranking military officials.
The test series was notable as containing the first time an AFAP shell was fired (GRABLE Shot), the first two shots (both fizzles) by University of California Radiation Laboratory—Livermore (now Lawrence Livermore National Laboratory), and for testing out some of the thermonuclear components that would be used for the massive thermonuclear series of Operation Castle. One primary device (RACER) was tested in thermonuclear system mockup assemblies of TX-14, TX-16, and TX-17/TX-24, to examine and evaluate the behaviour of radiation cases and the compression of the secondary geometries by the primary's x-rays prior to full-scale testing during Castle.[2]:192 Following RACER's dodgy performance, the COBRA primary was used in the emergency capability ALARM CLOCK, JUGHEAD, RUNT I, RUNT II thermonuclear devices, as well as in the SHRIMP device.[2]:200 RACER IV (as redesigned and proof-tested in the Simon test) was employed as primary for the ZOMBIE,[2]:200 RAMROD and MORGENSTERN[2]:318 devices.
Nuclear tests
Annie
Planned yield for Annie was 15 kilotonnes of TNT (63TJ), actual yield based on radiochemical analysis was 16.2 kilotonnes of TNT (68TJ).[3]
Nancy
Planned yield for Nancy was 40 kilotonnes of TNT (170TJ), actual yield based on radiochemical analysis was 24.5 kilotonnes of TNT (103TJ).[4]
Simon
Planned yield for Simon was 33 kilotonnes of TNT (140TJ), actual yield based on radiochemical analysis was 43.4 kilotonnes of TNT (182TJ).[5]
Harry
Planned yield for Harry was 37 kilotonnes of TNT (150TJ), actual yield based on radiochemical analysis was 27 kilotonnes of TNT (110TJ).[6]
Encore
Planned yield for Encore was 31 kilotonnes of TNT (130TJ), actual yield based on radiochemical analysis was 26 kilotonnes of TNT (110TJ).[7]
List of tests
United States' Upshot-Knothole series tests and detonations
Component test of TX-14[2]:193,195 containing minimal quantities of Li-6D.[2]:170Desert Rock V. First proof-test of the RACER boosted primary with disappointing performance.[Note 1]
1st UCRL device, a uranium deuteride core,[2]:202 meant to explore deuterated polyethylene mixed with uranium as thermonuclear fuel,[15]:chap.15[2]:203 and if successful to lead also to a compact thermonuclear primary.[2]:149 Predicted yield was 1.5 to 3 kilotons, max. theoretical was 20 kt.[14]:96 Device fizzled - deuterium moderated (slowed-down) neutrons more than expected and quenched the reaction. Embarrassing for designers, as it left 200ft (61m) of tower still standing (see image of tower).
TX-5D proof test, a boosting experiment using lithium deuteride in solid or crystalline form, investigating initiation via deuterium; a cheap method to initiate a chain reaction.[2]:185 Exploded 600ft (180m) ENE of intended zero point.
2nd UCRL device, uranium deuteride[2]:202 meant to explore deuterated polyethylene mixed with uranium as thermonuclear fuel,[15]:chap.15[2]:203 and if successful to lead also to a compact thermonuclear primary;[2]:149 Used different mix from Ruth[2]:202 and it also fizzled. A 100-foot tower was apparently used to avoid embarrassment in case of fizzle.
Component test of the TX-16 using a cryogenic mockup secondary and the TX-16 radiation case. Also tested RACER primary, which performed below expectations again. Desert Rock V.
Component test of TX-17/24 series using the RACER IV primary, a modified RACER core containing two additional kilograms of HEU in the original design tested in Nancy, a thermonuclear secondary mockup.[10]
New hollow core design, most efficient pure-plutonium device under 100kt indicates very good compression. Major effects testing of a high elevation explosion. Heaviest downwind contamination measured.
The 2nd of four gun-type device tests. Fired from the M65 Atomic Cannon "Atomic Annie" 11km (6.8mi) downrange. 280mm shell, 365kg (805lb). Detonation at 200 feet (61m) SW of target. Desert Rock V. Major effects test.
Proof test of a boosted MK-7 device, intended to be used as a primary in Castle. Initially it was intended only for the TX-15[2]:195. After RACER's inconsistent behaviour it was opted for all "emergency capability" devices instead.[2]:197. The bomb detonated 320ft (98m) NW of target. Composite implosion system in a Type D pit. Used Cyclotol 75/25 explosive mixture.
↑ The US, France and Great Britain have code-named their test events, while the USSR and China did not, and therefore have only test numbers (with some exceptions – Soviet peaceful explosions were named). Word translations into English in parentheses unless the name is a proper noun. A dash followed by a number indicates a member of a salvo event. The US also sometimes named the individual explosions in such a salvo test, which results in "name1 – 1(with name2)". If test is canceled or aborted, then the row data like date and location discloses the intended plans, where known.
↑ To convert the UT time into standard local, add the number of hours in parentheses to the UT time; for local daylight saving time, add one additional hour. If the result is earlier than 00:00, add 24 hours and subtract 1 from the day; if it is 24:00 or later, subtract 24 hours and add 1 to the day. Historical time zone data obtained from the IANA time zone database.
↑ Rough place name and a latitude/longitude reference; for rocket-carried tests, the launch location is specified before the detonation location, if known. Some locations are extremely accurate; others (like airdrops and space blasts) may be quite inaccurate. "~" indicates a likely pro-forma rough location, shared with other tests in that same area.
↑ Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or subtracted by tower, balloon, shaft, tunnel, air drop or other contrivance. For rocket bursts the ground level is "N/A". In some cases it is not clear if the height is absolute or relative to ground, for example, Plumbbob/John. No number or units indicates the value is unknown, while "0" means zero. Sorting on this column is by elevation and height added together.
↑ Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, and barge are all disallowed by the Partial Nuclear Test Ban Treaty. Sealed shaft and tunnel are underground, and remained useful under the PTBT. Intentional cratering tests are borderline; they occurred under the treaty, were sometimes protested, and generally overlooked if the test was declared to be a peaceful use.
↑ Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
↑ Designations for test items where known, "?" indicates some uncertainty about the preceding value, nicknames for particular devices in quotes. This category of information is often not officially disclosed.
↑ Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184gigajoules (1gigacalorie).
↑ Radioactive emission to the atmosphere aside from prompt neutrons, where known. The measured species is only iodine-131 if mentioned, otherwise it is all species. No entry means unknown, probably none if underground and "all" if not; otherwise notation for whether measured on the site only or off the site, where known, and the measured amount of radioactivity released.
Gallery
Full uncut detonation of Upshot-Knothole Grable, launched out of the Atomic Annie device on 5/25/1953. The footage at normal speed is about 2+1⁄2 minutes.
Close-up slow motion shot of Grable fire-ball, mach-stem and surface effects,
Upshot-Knothole Encore, 27-kilotons.
Upshot-Knothole Ruth, 0.2-kilotons.
Upshot-Knothole Ruth, Note close proximity to highway in foreground as to the scale of detonation.
The mangled tower for the Ruth test. The explosion failed to level the testing tower, only somewhat damaging it.
Related Research Articles
Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot–Knothole. The two explosions were staged in late 1952 at Enewetak Atoll in the Pacific Proving Ground in the Marshall Islands.
Operation Castle was a United States series of high-yield (high-energy) nuclear tests by Joint Task Force 7 (JTF-7) at Bikini Atoll beginning in March 1954. It followed Operation Upshot–Knothole and preceded Operation Teapot.
Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test principles that would lead to developing thermonuclear weapons. Conducted at the new Pacific Proving Ground, on islands of the Enewetak Atoll, it mounted the devices on large steel towers to simulate air bursts. This series of nuclear weapons tests was preceded by Operation Ranger and succeeded by Operation Buster-Jangle.
Operation Teapot was a series of 14 nuclear test explosions conducted at the Nevada Test Site in the first half of 1955. It was preceded by Operation Castle, and followed by Operation Wigwam. Wigwam was, administratively, a part of Teapot, but it is usually treated as a class of its own. The aims of the operation were to establish military tactics for ground forces on a nuclear battlefield and to improve the nuclear weapons used for strategic delivery.
Operation Plumbbob was a series of nuclear tests that were conducted between May 28 and October 7, 1957, at the Nevada Test Site, following Project 57, and preceding Project 58/58A.
The B83 is a variable-yield thermonuclear gravity bomb developed by the United States in the late 1970s that entered service in 1983. With a maximum yield of 1.2 megatonnes of TNT (5.0 PJ), it has been the most powerful nuclear weapon in the United States nuclear arsenal since October 25, 2011 after retirement of the B53. It was designed by Lawrence Livermore National Laboratory.
The B-41 was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States, with a maximum yield of 25 megatons of TNT. A top secret document, states “The US has stockpiled bombs of 9 MT and 23 MT...” which would likely be referring to the B-41's actual yield(s). The B-41 was the only three-stage thermonuclear weapon fielded by the U.S.
Mark 7 "Thor" was the First tactical fission bomb adopted by US armed forces. It was also the first weapon to be delivered using the toss method with the help of the low-altitude bombing system (LABS). The weapon was tested in Operation Buster-Jangle. To facilitate external carry by fighter-bomber aircraft, Mark 7 was fitted with retractable stabilizer fins. The Mark 7 warhead (W7) also formed the basis of the 30.5 inches (775 mm) BOAR rocket, the Mark 90 Betty nuclear depth charge, MGR-1 Honest John rocket, and MGM-5 Corporal ballistic missile. It was also supplied for delivery by Royal Air Force Canberra aircraft assigned to NATO in Germany under the command of SACEUR. This was done under the auspices of Project E, an agreement between the United States and the UK on the RAF carriage of US nuclear weapons. In UK use it was designated 1,650 lb. H.E. M.C. The Mark 7 was in service from 1952 to 1967(8) with 1700–1800 having been built.
The explosive yield of a nuclear weapon is the amount of energy released such as blast, thermal, and nuclear radiation, when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotonnes (kt—thousands of tonnes of TNT), in megatonnes (Mt—millions of tonnes of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to 0.239 kilotonnes of TNT. Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kilotonne of TNT is held simply to be equivalent to 1012 calories.
The W50 was an American thermonuclear warhead deployed on the MGM-31 Pershing theater ballistic missile. Initially developed for the LIM-49 Nike Zeus anti-ballistic missile, this application was cancelled before deployment. The W50 was developed by Los Alamos National Laboratory. The W50 was manufactured from 1963 through 1965, with a total of 280 being produced. They were retired from service starting in 1973 with the last units retired in 1991.
Kinglet was a boosted fission primary used in several American thermonuclear weapons.
The W33 was an American nuclear artillery shell designed for use in the 8-inch (203 mm) M110 howitzer and M115 howitzer.
Upshot–Knothole Grable was a nuclear weapons test conducted by the United States as part of Operation Upshot–Knothole. Detonation of the nuclear weapon, a W9 warhead, occurred 19 seconds after its deployment at 8:30am PDT on May 25, 1953, in Area 5 of the Nevada Test Site.
Operation Redwing was a United States series of 17 nuclear test detonations from May to July 1956. They were conducted at Bikini and Enewetak atolls by Joint Task Force 7 (JTF7). The entire operation followed Project 56 and preceded Project 57. The primary intention was to test new, second-generation thermonuclear weapons. Also tested were fission devices intended to be used as primaries for thermonuclear weapons, and small tactical weapons for air defense. Redwing demonstrated the first United States airdrop of a deliverable hydrogen bomb during test Cherokee. Because the yields for many tests at Operation Castle in 1954 were dramatically higher than predictions, Redwing was conducted using an "energy budget": There were limits to the total amount of energy released, and the amount of fission yield was also strictly controlled. Fission, primarily "fast" fission of the natural uranium tamper surrounding the fusion capsule, greatly increases the yield of thermonuclear devices, and constitutes the great majority of the fallout, as nuclear fusion is a relatively clean reaction.
RACER IV was a component of some of the first hydrogen bombs made by the United States during the 1950s. The RACER was developed in 1953 at Los Alamos National Laboratory.
The uranium hydride bomb was a variant design of the atomic bomb first suggested by Robert Oppenheimer in 1939 and advocated and tested by Edward Teller. It used deuterium, an isotope of hydrogen, as a neutron moderator in a uranium-deuterium ceramic compact. Unlike all other fission-bomb types, the concept relies on a chain reaction of slow nuclear fission. Bomb efficiency was harmed by the slowing of neutrons since the latter delays the reaction, as delineated by Rob Serber in his 1992 extension of the original Los Alamos Primer.
A fizzle occurs when the detonation of a device for creating a nuclear explosion grossly fails to meet its expected yield. The bombs still detonate, but the detonation is much less than anticipated. The cause(s) for the failure can be linked to improper design, poor construction, or lack of expertise. All countries that have had a nuclear weapons testing program have experienced some fizzles. A fizzle can spread radioactive material throughout the surrounding area, involve a partial fission reaction of the fissile material, or both. For practical purposes, a fizzle can still have considerable explosive yield when compared to conventional weapons.
Upshot–Knothole Harry (UK#9) was a nuclear weapons test conducted by the United States as part of Operation Upshot–Knothole. It took place at the recorded time of 04:05 hours, on May 19, 1953, in Yucca Flat, in the Nevada Test Site. The sponsor of the test was the National Laboratory of the United States of America located at Los Alamos.
Upshot–Knothole Annie was one of eleven nuclear weapons tests conducted by the United States as part of Operation Upshot–Knothole. It took place at the Nevada Test Site on 17 March 1953, and was nationally televised. The device used in the blast was a 16 kt Mark 5 Nuclear Bomb - a low yield fission weapon, detonated 90 meters / 300 feet above the ground. The live TV coverage was recorded on a kinescope, so it is a rare record of the sound an actual atomic bomb makes.
Operation Dominic was a series of 31 nuclear test explosions ("shots") with a 38.1 Mt (159 PJ) total yield conducted in 1962 by the United States in the Pacific. This test series was scheduled quickly, in order to respond in kind to the Soviet resumption of testing after the tacit 1958–1961 test moratorium. Most of these shots were conducted with free fall bombs dropped from B-52 bomber aircraft. Twenty of these shots were to test new weapons designs; six to test weapons effects; and several shots to confirm the reliability of existing weapons. The Thor missile was also used to lift warheads into near-space to conduct high-altitude nuclear explosion tests; these shots were collectively called Operation Fishbowl.
References
Notes
↑ Apparently the device name is a misnomer, as it implies that the device tested was related to the TX-15 "ZOMBIE". However, this is not the case; no thermonuclear component testing of TX-15 appears to have been conducted during this operation, since Upshot-Knothole tested radiation implosion mockups, containing primaries and mocked-up secondaries with small amounts of enriched Li-6 for the TX-14, TX-16, and TX-17/24 thermonuclear prototype systems, all slated to be proof-fired during CASTLE.[2]:193
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