| Operation Plumbbob | |
|---|---|
 Plumbbob-Priscilla, 37 kilotons | |
 | |
| Information | |
| Country | United States |
| Test site |
|
| Period | 1957 |
| Number of tests | 29 |
| Test type | balloon, dry surface, high alt rocket (30–80 km), tower, underground shaft, tunnel |
| Max. yield | 74kilotonnes of TNT (310 TJ) |
| Test series chronology | |
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Operation Plumbbob was a series ofnuclear tests that were conducted between May 28 and October 7, 1957, at theNevada Test Site, followingProject 57, and precedingProject 58/58A.[1]
The operation consisted of 29explosions, of which only two did not produce any nuclearyield. Twenty-one laboratories and government agencies were involved. While mostOperation Plumbbob tests contributed to the development ofwarheads forintercontinental andintermediate rangemissiles, they also testedair defense andanti-submarine warheads with smaller yields. They included 43 military effects tests on civil and military structures,radiation and bio-medical studies, and aircraft structural tests.Operation Plumbbob had the tallest tower tests to date in the U.S. nuclear testing program as well as high-altitudeballoon tests. One nuclear test involved the largest troop maneuver ever associated with U.S. nuclear testing.
Approximately 18,000 members of the U.S.Air Force,Army,Navy andMarines participated in exercisesDesert Rock VII andVIII during Operation Plumbbob. The military was interested in knowing how the average foot-soldier would stand up, physically and psychologically, to the rigors of the tacticalnuclear battlefield.
Almost 1,200 pigs were subjected to bio-medical experiments and blast-effects studies during Operation Plumbbob. On shotPriscilla (37 kt), 719 pigs were used in various experiments onFrenchman Flat. Some pigs were placed in elevated cages and provided with suits made of different materials, to test which materials provided best protection from thethermal radiation. As shown and reported in thePBS documentaryDark Circle, the pigs survived, but with third-degree burns to 80% of their bodies.[2] Other pigs were placed in pens behind large sheets of glass at measured distances from thehypocenter to test the effects of flying debris on living targets.
Studies were conducted ofradioactive contamination andfallout from a simulated accidental detonation of a weapon, and projects concerning earth motion, blast loading andneutron output were carried out.
Nuclear weapons safety experiments were conducted to study the possibility of a nuclear weapon detonation during an accident. On July 26, 1957, a safety experiment,Pascal-A, was detonated in an unstemmed hole at the Nevada Test Site, becoming the first underground shaft nuclear test. The knowledge gained provided data to predict nuclear yields in case of accidental detonations—for example, in aplane crash.
TheJohn shot on July 19, 1957, was the only test of the Air Force'sAIR-2A Genie rocket with a nuclear warhead.[3] It was fired from anF-89J Scorpion fighter over Yucca Flats at theNevada National Security Site. On the ground, the Air Force carried out a public relations event by having five Air Force officers and a motion picture photographer stand under ground zero of the blast, which took place at between 18,500 and 20,000 feet (5,600 and 6,100 m) altitude, with the idea of demonstrating the possibility of the use of the weapon over civilian populations without ill effects.[4] The five officers were Colonel Sidney C. Bruce, later professor of Electrical Engineering at Colorado University, died in 2005; Lieutenant Colonel Frank P. Ball, died in 2003; Major John W. Hughes II, died in 1990; Major Norman B. Bodinger, died in 1997; Major Donald A. Luttrell, died in 2014.[5] The videographer, Akira "George" Yoshitake, died in 2013.[6]
TheRainier shot, conducted September 19, 1957, was the first fully contained underground nuclear test, meaning that no fission products were vented into the atmosphere. This test of 1.7 kt could be detected around the world byseismologists using ordinary seismic instruments. TheRainier test became the prototype for larger and more powerful underground tests.
Images fromUpshot-Knothole Grable were accidentally relabeled as belonging to thePriscilla shot fromOperation Plumbbob in 1957. As a consequence publications including official government documents have the photo mislabeled.[7] The shots can be told apart by the trails of test rockets, which are prominently featured in images and footage ofGrable, but appear almost completely absent at the actualPriscilla shot.[failed verification]
In 1956, Robert Brownlee, fromLos Alamos National Laboratory inNew Mexico, was asked to examine whether nuclear detonations could be conducted underground. The first subterranean test was the nuclear device known as Pascal A, which was lowered down a 500 ft (150 m) borehole. However, the detonated yield turned out to be 50,000 times greater than anticipated, creating a jet of fire that shot hundreds of meters into the sky.[8] During the Pascal-B nuclear test of August 1957,[8][9] a 900-kilogram (2,000 lb) steel lid was welded over the borehole to contain the nuclear blast, despite Brownlee predicting that it would not work.[8] When Pascal-B was detonated, the blast went straight up the test shaft, launching the cap into the atmosphere. The plate was never found.[10] Scientists believe compression heating caused the cap to vaporize as it sped through the atmosphere.[8] A high-speed camera, which took one frame permillisecond, was focused on the borehole because studying the velocity of the plate was deemed scientifically interesting.[8] After the detonation, the plate appeared in only one frame. Regarding its speed Brownlee reckoned that "a lower limit could be calculated by considering the time between frames (and I don't remember what that was)", and joked that the best estimate was it was "goinglike a bat!".[10]
| Name | Date time (UT) (local:PST, −8 hrs)[note 1] | Location[note 2] | Elevation + height[note 3] | Delivery[note 4] Purpose[note 5] | Device[note 6] | Yield[note 7] | Fallout[note 8] | References | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Boltzmann | May 28, 1957 11:55:00.2 | NTS Area 7c37°05′41″N116°01′28″W / 37.0947°N 116.0245°W /37.0947; -116.0245 (Boltzmann) | 1,294 m (4,245 ft) + 150 m (490 ft) | tower, weapons development | XW-40 | 12 kt | I-131 venting detected, 1.9 MCi (70 PBq) | [1][11][12][13][14][15] | XW-40 lightweight boosted fission warhead test. |
| Franklin | June 2, 1957 11:54:59.9 | NTS Area T337°02′52″N116°01′19″W / 37.0477°N 116.022°W /37.0477; -116.022 (Franklin) | 1,229 m (4,032 ft) + 90 m (300 ft) | tower, weapons development | XW-30 ? | 140 t | I-131 venting detected, 19 kCi (700 TBq) | [1][11][12][13][14][15] | XW-30 warhead test, fizzled. Retested successfully withFranklin Prime, with more fissile material in the core and different explosives. |
| Lassen | June 5, 1957 11:45:00.3 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Lassen) | 1,595 m (5,233 ft) + 150 m (490 ft) | balloon, weapons development | 600 t | I-131 venting detected, 100 Ci (3,700 GBq) | [1][11][12][15] | Fizzle, unboosted all-oralloy small weapon design. | |
| Wilson | June 18, 1957 11:45:00.3 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Wilson) | 1,589 m (5,213 ft) + 150 m (490 ft) | balloon, weapons development | XW-45X1 | 10 kt | I-131 venting detected, 1.5 MCi (56 PBq) | [1][11][12][14][15] | XW-45X1 Swan test, gas-boosted composite pit. |
| Priscilla | June 24, 1957 13:30:00.1 | NTS Area 536°47′53″N115°55′47″W / 36.798°N 115.9298°W /36.798; -115.9298 (Priscilla) | 940 m (3,080 ft) + 210 m (690 ft) | balloon, weapons development | Mk-15/39 primary | 37 kt | I-131 venting detected, 5.8 MCi (210 PBq) | [1][12][13][14][15] | Effects shot with OTS weapon. Similar to that tested inRedwing Lacrosse. |
| Coulomb-A | July 1, 1957 17:30:?? | NTS Area S3h37°03′11″N116°02′02″W / 37.053°N 116.034°W /37.053; -116.034 (Coulomb-A) | 1,231 m (4,039 ft) + 0 | dry surface, safety experiment | XW-31 | no yield | [1][11][12][14][15][16] | Safety experiment, successful. | |
| Hood | July 5, 1957 11:40:00.1 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Hood) | 1,285 m (4,216 ft) + 460 m (1,510 ft) | balloon, weapons development | Swan primary and Whistle secondary. Full-scale test of device wasHardtack I Maple shot.[17] | 74 kt | I-131 venting detected, 11 MCi (410 PBq) | [1][11][12][13][15] | Largest atmospheric test in CONUS. Was a 2-stage thermonuclear device, even though AEC stated that no thermonuclear devices were being tested at the NTS.Desert Rock VII. |
| Diablo | July 15, 1957 11:30:00.1 | NTS Area T2b37°09′01″N116°06′34″W / 37.1502°N 116.1095°W /37.1502; -116.1095 (Diablo) | 1,367 m (4,485 ft) + 150 m (490 ft) | tower, weapons development | Swan | 17 kt | I-131 venting detected, 2.5 MCi (93 PBq) | [1][11][12][13][15] | Very similar to theShasta test device. 2 stage. Misfired on 28 June. |
| John | July 19, 1957 14:00:04.6 | Launch from NTS, Areas 1–4, 6–10, Yucca Flat: 1037°00′00″N116°03′14″W / 37°N 116.0539°W /37; -116.0539 (Launch_John), elv: 1,220 + 5,600 m (4,000 + 18,370 ft); Detonation overNTS37°09′38″N116°03′14″W / 37.1605°N 116.0539°W /37.1605; -116.0539 (John) | 1,280 m (4,200 ft) + 5,639 m (18,501 ft) | Air launched rocket, weapon effect | W-25 | 2 kt | I-131 venting detected, 6.1MCi? | [1][12][13][14][15] | Proof test ofAIR-2A Genie air-to-air rocket. Test made famous by five USAF officers and a videographer standing at ground zero below the hypocentre and during the detonation, flash and blast. |
| Kepler | July 24, 1957 11:49:59.9 | NTS Area 437°05′44″N116°06′13″W / 37.09549°N 116.10354°W /37.09549; -116.10354 (Kepler) | 1,318 m (4,324 ft) + 150 m (490 ft) | tower, weapons development | XW-35 primary? | 10 kt | I-131 venting detected, 1.7 MCi (63 PBq) | [1][11][12][13][14][15] | ICBM warhead, similar toHardtack I/Koa. |
| Owens | July 25, 1957 13:29:59.7 | NTS Area B9b ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Owens) | 1,260 m (4,130 ft) + 150 m (490 ft) | balloon, weapons development | XW-51 ? | 9.7 kt | I-131 venting detected, 1.7 MCi (63 PBq) | [1][11][12][14][15] | Very small boostedplutonium device, XW-51 progenitor. |
| Pascal-A | July 26, 1957 08:00:00.0 | NTS Area U3j37°03′06″N116°02′03″W / 37.05175°N 116.03415°W /37.05175; -116.03415 (Pascal-A) | 1,202 m (3,944 ft)–150 m (490 ft) | underground shaft, safety experiment | 55 t | I-131 venting detected, 10 kCi (370 TBq) | [1][12][13][15] | OriginallyGalileo A. One-point safety experiment, failure. Expected yield was less than 1 kg. A concrete cylinder perhaps 2 m (6 ft 7 in) thick 100 m (330 ft) up the tube disappeared. | |
| Stokes | August 7, 1957 12:25:00.2 | NTS Area B7b ~37°05′12″N116°01′28″W / 37.0866°N 116.0245°W /37.0866; -116.0245 (Stokes) | 1,250 m (4,100 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-30 | 19 kt | I-131 venting detected, 2.8 MCi (100 PBq) | [1][11][12][13][14][15] | Tactical Atomic Demolition Munition (TADM) and Talos SAM warhead. |
| Saturn | August 10, 1957 00:59:55.1 | NTS Area U12c.0237°11′37″N116°12′02″W / 37.19355°N 116.20059°W /37.19355; -116.20059 (Saturn) | 1,231 m (4,039 ft)–39.01 m (128.0 ft) | tunnel, safety experiment | XW-45X1 | 50 kg | [1][12][14][15][18] | One-point safety experiment; first shot in a Rainier tunnel. | |
| Shasta | August 18, 1957 12:00:00.0 | NTS Area 2a37°07′41″N116°06′26″W / 37.128°N 116.1073°W /37.128; -116.1073 (Shasta) | 1,339 m (4,393 ft) + 150 m (490 ft) | tower, weapons development | Swan | 17 kt | I-131 venting detected, 2.5 MCi (93 PBq) | [1][11][12][13][15] | 2 stage thermonuclear design. |
| Doppler | August 23, 1957 12:30:00.1 | NTS Area B7b ~37°05′12″N116°01′28″W / 37.0866°N 116.0245°W /37.0866; -116.0245 (Doppler) | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-34 ? | 11 kt | I-131 venting detected, 1.7 MCi (63 PBq) | [1][11][12][13][14][15] | LASL gas boosted implosion device, possible XW-34 test. |
| Pascal-B | August 27, 1957 22:35:00.0 | NTS Area U3d37°02′57″N116°02′05″W / 37.04903°N 116.0347°W /37.04903; -116.0347 (Pascal-B) | 1,229 m (4,032 ft)–150 m (490 ft) | underground shaft, safety experiment | 300 t | [1][11][12][13][15] | Shaft safety experiment, failed. Sent the shaft cap weighing several hundred pounds (1 ton) at velocity very roughly pre-calculated as 66 km/s (41 mi/s); popular claims of it reaching space are disputed, see section above. | ||
| Franklin Prime | August 30, 1957 12:39:59.9 | NTS Area B7b ~37°05′12″N116°01′28″W / 37.0866°N 116.0245°W /37.0866; -116.0245 (Franklin Prime) | 1,282 m (4,206 ft) + 230 m (750 ft) | balloon, weapons development | 4.7 kt | I-131 venting detected, 690 kCi (26,000 TBq) | [1][11][12][13][14][15] | Retest ofFranklin with more U-235. | |
| Smoky | August 31, 1957 12:30:00.0 | NTS Area T2c37°11′14″N116°04′08″W / 37.18712°N 116.06887°W /37.18712; -116.06887 (Smoky) | 1,367 m (4,485 ft) + 210 m (690 ft) | tower, weapons development | TX-41 primary | 44 kt | I-131 venting detected, 6.4 MCi (240 PBq) | [1][11][12][13][14][15][19] | 2 stages of 3 stage thermonuke, similar toRedwing/Zuni andTewa. Desert Rock VII; 3000 servicemen irradiated; 10 of 4 expected leukemia cases in the 80s. Last pristine air-drop location at the NTS. |
| Galileo | September 2, 1957 12:40:00.0 | NTS Area T137°03′11″N116°06′12″W / 37.053°N 116.1034°W /37.053; -116.1034 (Galileo) | 1,294 m (4,245 ft) + 150 m (490 ft) | tower, weapons development | 11 kt | I-131 venting detected, 1.9 MCi (70 PBq) | [1][11][12][13][15] | LASL diagnostic/exploratory test of boosted fission device. Desert Rock VIII. | |
| Wheeler | September 6, 1957 12:45:00.0 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Wheeler) | 1,286 m (4,219 ft) + 150 m (490 ft) | balloon, weapons development | XW-51 ? | 197 t | I-131 venting detected, 27 kCi (1,000 TBq) | [1][11][12][14][15] | Retest of redesignedLassen device, possible XW-51 air-to-air warhead progenitor. |
| Coulomb-B | September 6, 1957 20:05:00.6 | NTS Area S3g37°02′34″N116°01′40″W / 37.0427°N 116.0277°W /37.0427; -116.0277 (Coulomb-B) | 1,225 m (4,019 ft) + 0 | dry surface, safety experiment | XW-31 | 300 t | I-131 venting detected, 42 kCi (1,600 TBq) | [1][11][12][14][15] | One-point safety experiment, high limits test, expected 1 kg TNT equivalent, max .2 kt - failure. |
| Laplace | September 8, 1957 12:59:59.8 | NTS Area B7b ~37°05′12″N116°01′28″W / 37.0866°N 116.0245°W /37.0866; -116.0245 (Laplace) | 1,282 m (4,206 ft) + 230 m (750 ft) | balloon, weapons development | XW-33 "Fleegle" | 1 kt | I-131 venting detected, 140 kCi (5,200 TBq) | [1][11][12][15] | Oralloy gun-type device, for a nuclear artillery shell. The third of only four gun-type weapons, withLittle Boy, Grable andAardvark. |
| Fizeau | September 14, 1957 16:44:59.8 | NTS Area T3b37°02′01″N116°01′56″W / 37.0336°N 116.0323°W /37.0336; -116.0323 (Fizeau) | 1,220 m (4,000 ft) + 150 m (490 ft) | tower, weapons development | XW-34 ? | 11 kt | I-131 venting detected, 1.7 MCi (63 PBq) | [1][11][12][13][14][15] | LASL boosted fission device. Possibly a test of the XW-34 depth bomb. |
| Newton | September 16, 1957 12:49:59.9 | NTS Area B7a ~37°05′12″N116°01′28″W / 37.0866°N 116.0245°W /37.0866; -116.0245 (Newton) | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-31 | 12 kt | I-131 venting detected, 2.1 MCi (78 PBq) | [1][11][12][13][14][15] | LASL test of XW-31 variant, boosted primary in thermonuclear system mockup. Sounds like a fizzle, but no one says so. |
| Rainier | September 19, 1957 16:59:59.45 | NTS Area U12b37°11′45″N116°12′15″W / 37.19573°N 116.20404°W /37.19573; -116.20404 (Rainier) | 2,295 m (7,530 ft)–272.8 m (895 ft) | tunnel, weapons development | W-25 | 1.7 kt | [1][11][12][13][14][15][18] | First US underground nuclear test. Evaluate containment and detection of underground testing, formed a chimney of broken rock which provided data on possible underground engineering applications of nuclear explosives. | |
| Whitney | September 23, 1957 12:29:59.8 | NTS Area T237°08′18″N116°07′06″W / 37.1383°N 116.1184°W /37.1383; -116.1184 (Whitney) | 1,370 m (4,490 ft) + 150 m (490 ft) | tower, weapons development | W27 primary | 19 kt | I-131 venting detected, 2.9 MCi (110 PBq) | [1][11][12][14][15] | Test of boosted Swan primary in W-27 thermonuclear system mockup. |
| Charleston | September 28, 1957 12:59:59.9 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Charleston) | 1,285 m (4,216 ft) + 460 m (1,510 ft) | balloon, weapons development | 12 kt | I-131 venting detected, 1.8 MCi (67 PBq) | [1][11][12][13][15] | UCRL test of a small "clean" tactical 2-stage thermonuclear device. Device fizzled when second stage failed to fire. | |
| Morgan | October 7, 1957 13:00:00.1 | NTS Area B9a ~37°08′05″N116°02′30″W / 37.1347°N 116.0417°W /37.1347; -116.0417 (Morgan) | 1,285 m (4,216 ft) + 150 m (490 ft) | balloon, weapons development | XW-45X1 Swan/ | 8 kt | I-131 venting detected, 1.2 MCi (44 PBq) | [1][11][12][14][15] |
