Editing Operation Plumbbob

{{Short description|Series of 1950s American nuclear tests}}
{{Use mdy dates|date=November 2018}}
{{Infobox nuclear weapons test
 |name                = Operation Plumbbob
 |picture             = [[File:Plumbbob Priscilla2.gif|300px]]
 |picture_description = Plumbbob-''Priscilla'', 37 kilotons.
 |country             = United States
 |test_site           = {{plainlist|
*NTS Area 12, Rainier Mesa
*NTS Areas 5, 11, Frenchman Flat
*NTS, Areas 1–4, 6–10, Yucca Flat}}
 |period              = 1957
 |number_of_tests     = 29
 |test_type           = balloon, dry surface, high alt rocket (30&ndash;80&nbsp;km), tower, underground shaft, tunnel
 |max_yield           = {{convert|74|ktTNT|lk=in}}
 |previous_series     = [[Project 57]]
 |next_series         = [[Project 58/58A]]
}}
{{GeoGroup|article=Operation Plumbbob}}
'''Operation Plumbbob''' was a series of [[Nuclear testing|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]]''.<ref name=LT_1 />

==Background==

The operation consisted of 29 [[Effects of nuclear explosions|explosions]], of which only two did not produce any nuclear [[nuclear weapon yield|yield]]. Twenty-one laboratories and government agencies were involved. While most ''Operation Plumbbob'' tests contributed to the development of [[warhead]]s for [[Intercontinental ballistic missile|intercontinental]] and [[Intermediate-range ballistic missile|intermediate]] range [[missile]]s, they also tested [[Anti-aircraft warfare|air defense]] and [[Anti-submarine weapon|anti-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-altitude [[balloon]] tests. One nuclear test involved the largest troop maneuver ever associated with U.S. nuclear testing.

Approximately 18,000 members of the U.S. [[United States Air Force|Air Force]], [[United States Army|Army]], [[United States Navy|Navy]] and [[United States Marine Corps|Marines]] participated in exercises [[Desert Rock VII]] and [[Desert Rock VIII|VIII]] 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 tactical [[Nuclear warfare|nuclear battlefield]].

Almost 1,200 pigs were subjected to bio-medical experiments and blast-effects studies during Operation Plumbbob. On shot ''Priscilla'' (37&nbsp;kt), 719 pigs were used in various experiments on [[Frenchman Flat]]. Some pigs were placed in elevated cages and provided with suits made of different materials, to test which materials provided best protection from the [[Effects of nuclear explosions#Thermal radiation|thermal radiation]]. As shown and reported in the [[PBS]] documentary ''[[Dark Circle (film)|Dark Circle]]'', the pigs survived, but with third-degree burns to 80% of their bodies.<ref>{{Cite AV media |url=https://www.pbs.org/pov/darkcircle/ |title=Dark Circle |date=March 27, 2007 |people=Judy Irving, Chris Beaver, Ruth Landy (directors) |type=DVD |isbn=0-7670-9304-6 |access-date=September 7, 2017 |archive-date=August 11, 2019 |archive-url=https://web.archive.org/web/20190811113037/http://www.pbs.org/pov/darkcircle/ |url-status=live }}</ref> Other pigs were placed in pens behind large sheets of glass at measured distances from the [[hypocenter]] to test the effects of flying debris on living targets.

Studies were conducted of [[radioactive contamination]] and [[Nuclear fallout|fallout]] from a simulated accidental detonation of a weapon, and projects concerning earth motion, blast loading and [[neutron]] 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 prevent nuclear yields in case of accidental detonations—for example, in a [[Aviation accidents and incidents|plane crash]].

{{anchor|John}}
The ''John'' shot on July 19, 1957, was the only test of the Air Force's [[AIR-2_Genie|AIR-2A Genie]] rocket with a nuclear warhead.<ref>{{cite news|title=Five Men Agree To Stand Directly Under An Exploding Nuclear Bomb|author=Robert Krulwich|newspaper=NPR|date=July 17, 2012|url=https://www.npr.org/blogs/krulwich/2012/07/16/156851175/five-men-agree-to-stand-directly-under-an-exploding-nuclear-bomb|access-date=April 3, 2018|archive-date=April 26, 2015|archive-url=https://web.archive.org/web/20150426133157/http://www.npr.org/blogs/krulwich/2012/07/16/156851175/five-men-agree-to-stand-directly-under-an-exploding-nuclear-bomb|url-status=live}}</ref> It was fired from an [[Northrop F-89 Scorpion|F-89J Scorpion]] fighter over Yucca Flats at the [[Nevada 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 {{convert|18,500|and|20,000|ft|m}} altitude, with the idea of demonstrating the possibility of the use of the weapon over civilian populations without ill effects.<ref>{{cite news|title=George Yoshitake, Nuclear Test Photographer, Recalls Filming Nuclear Blast 55 Years Ago|author=Timothy Stenovec|publisher=Huffington Post|url=http://www.huffingtonpost.com/2012/07/20/george-yoshitake-nuclear-test-five-5-men-nevada_n_1687233.html|date=July 20, 2012|access-date=July 22, 2013|archive-date=December 14, 2012|archive-url=https://web.archive.org/web/20121214073601/http://www.huffingtonpost.com/2012/07/20/george-yoshitake-nuclear-test-five-5-men-nevada_n_1687233.html|url-status=live}}</ref> 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.<ref>{{cite news| title=Donald Allen Luttrell (obituary)| newspaper=Dallas Morning News| date=January 1, 2015| url=http://www.legacy.com/obituaries/dallasmorningnews/obituary.aspx?pid=173687969| access-date=February 15, 2015| archive-date=March 3, 2016| archive-url=https://web.archive.org/web/20160303204709/http://www.legacy.com/obituaries/dallasmorningnews/obituary.aspx?pid=173687969| url-status=live}}</ref> The videographer, Akira "George" Yoshitake, died in 2013.<ref>{{cite news| title=Akira "George" Yoshitake (obituary)| newspaper=Lompoc Record| location=Lompoc, California, US| date=October 22, 2013| url=http://www.lompocrecord.com/lifestyles/announcements/obituaries/akira-george-yoshitake/article_e7d7490d-8347-5fab-a8ed-6e0adf725271.html| access-date=May 17, 2014| archive-date=June 14, 2017| archive-url=https://web.archive.org/web/20170614005708/http://lompocrecord.com/lifestyles/announcements/obituaries/akira-george-yoshitake/article_e7d7490d-8347-5fab-a8ed-6e0adf725271.html| url-status=live}}</ref>

{{anchor|Rainier}}
The ''Rainier'' 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&nbsp;kt could be detected around the world by [[Seismology|seismologists]] using ordinary seismic instruments. The ''Rainier'' test became the prototype for larger and more powerful underground tests.

{{anchor|Priscilla}}
Images from ''[[Upshot-Knothole Grable]]'' were accidentally relabeled as belonging to the ''Priscilla'' shot from ''Operation Plumbbob'' in 1957. As a consequence publications including official government documents have the photo mislabeled. The shots can be told apart by the trails of test rockets, which are prominently featured in images and footage of ''Grable'', but appear almost completely absent at the actual ''Priscilla'' shot.<ref>{{Cite web |last=Sublette |first=Carey |title=Operation Plumbbob |url=http://nuclearweaponarchive.org/Usa/Tests/Plumbob.html |url-status=live |archive-url=https://web.archive.org/web/20031213232218/http://nuclearweaponarchive.org/Usa/Tests/Plumbob.html |archive-date=December 13, 2003 |access-date=December 27, 2006 |website=Nuclear Weapon Archive}}</ref>

==Missing steel bore cap==

{{anchor|Pascal-B|Missing steel bore cap}} In 1956, Robert Brownlee, from [[Los Alamos National Laboratory]] in [[New 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  {{convert|500|ft|abbr=on}} 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.<ref name="register"/> During the Pascal-B nuclear test of August 1957,<ref name="register" /><ref name="Brownlee, Harrington">{{cite web
 |url          = https://www.businessinsider.com/fastest-object-robert-brownlee-2016-2?r=US&IR=T#brownlee-wanted-to-measure-how-fast-the-iron-cap-flew-off-the-column-so-he-designed-a-second-experiment-pascal-b-9
 |author       = Harrington, Rebecca
 |date         = February 5, 2016
 |title        = The fastest object ever launched was a manhole cover – here's the story from the guy who shot it into space
 |work         = [[Tech Insider]] - www.businessinsider.com [[Business Insider]]
 |accessdate   = 11 June 2021
 |archive-date = November 1, 2020
 |archive-url  = https://web.archive.org/web/20201101025542/https://www.businessinsider.com/fastest-object-robert-brownlee-2016-2?r=US&IR=T#brownlee-wanted-to-measure-how-fast-the-iron-cap-flew-off-the-column-so-he-designed-a-second-experiment-pascal-b-9
 |url-status   = live
}}</ref> a {{convert|900|kg|adj=on}} iron lid was welded over the borehole to contain the nuclear blast, despite Brownlee predicting that it would not work.<ref name="register"/> When Pascal-B was detonated, the blast went straight up the test shaft, launching the cap into the atmosphere. The plate was never found.<ref name="brownlee" /> Scientists believe compression heating caused the cap to vaporize as it sped through the atmosphere.<ref name="register">{{cite web | url = https://www.theregister.com/2015/07/16/america_soviets_space_race/ | author = Thomson, Iain | title = Science: Did speeding American manhole cover beat Sputnik into space? Top boffin speaks to El Reg - How a nuke blast lid may have beaten Soviets by months | date = 16 July 2015 | website = [[The Register]] | accessdate = 11 June 2021 | archive-date = May 7, 2021 | archive-url = https://web.archive.org/web/20210507102307/https://www.theregister.com/2015/07/16/america_soviets_space_race/ | url-status = live }}</ref> A high-speed camera, which took one frame per [[millisecond]], was focused on the borehole because studying the velocity of the plate was deemed scientifically interesting.<ref name="register"/> 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 "going [[wikt:like a bat out of hell|like a bat]]!".<ref name=brownlee /> Brownlee estimated that the explosion, combined with the specific design of the shaft, could accelerate the plate to approximately six times Earth's [[escape velocity]].<ref name=brownlee>{{cite web| url=http://nuclearweaponarchive.org/Usa/Tests/Brownlee.html| title=Learning to Contain Underground Nuclear Explosions| first=Robert R.| last=Brownlee|date=June 2002| access-date=July 31, 2006}}</ref>

==List of tests==

{{See also|List of nuclear weapons tests of the United States}}

{| class="wikitable sortable"
 |+ United States' Plumbbob series tests and detonations
 |-
! style="background:#fda" | Name
! style="background:#eee" | Date time ([[Universal Time|UT]])<br> ([[time zone|local]]: [[Pacific Standard Time|PST]], −8&nbsp;hrs)<ref group=note>To convert the UT into standard local PST, subtract 8 hours. If the result is earlier than 00:00, add 24 hours and subtract 1 from the day. Historical time zone data are derived from {{cite web| title=Time Zone Historical Database| publisher=iana.com| url=http://www.ietf.org/timezones/| access-date=March 8, 2014| archive-date=March 11, 2014| archive-url=https://web.archive.org/web/20140311224729/http://www.ietf.org/timezones/| url-status=live}}</ref>
 ! style="background:#eee" | [[List of nuclear test sites|Location]]<ref group=note>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.</ref>
 ! style="background:#fda" | [[Elevation]] + height <ref group=note>Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or 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.</ref>
 !style="background:#eee" | Delivery <ref group=note>Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, and barge have all been disallowed by the [[Partial Nuclear Test Ban Treaty]] since 1963. 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.</ref><br />Purpose <ref group=note>Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.</ref>
 !style="background:#eee" | [[List of nuclear weapons|Device]]<ref group=note>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.</ref>
 !style="background:#fda" | [[Nuclear weapon yield|Yield]]<ref group=note>Estimated energy yield in [[TNT equivalent|tons or kilotons]]. A ton of TNT equivalent is defined as 4.184&nbsp;gigajoules (1&nbsp;gigacalorie).</ref>
 !style="background:#eee" class="unsortable" | [[Nuclear fallout|Fallout]]<ref group=note>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.</ref>
 !style="background:#fda" class="unsortable" | References
 !style="background:#eee" class="unsortable" | Notes
 |-
 ! ''Boltzmann''{{anchor|Boltzmann}}
 | {{dts|1957|5|28}} 11:55:00.2
 | [[Nevada National Security Site|NTS]] Area 7c {{coord|37.0947|-116.0245|name=Boltzmann|display=inline}}
 | {{sort|001444|}}{{convert|1294|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | [[W40 (nuclear warhead)|XW-40]]
 | style="text-align:center;" | {{sort|000120000|12&nbsp;kt}}
 | I-131 venting detected, {{convert|1.9|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | XW-40 lightweight boosted fission warhead test.
 |-
 ! ''Franklin''{{anchor|Franklin}}
 | {{dts|1957|6|2}} 11:54:59.9
 | [[Nevada National Security Site|NTS]] Area T3 {{coord|37.0477|-116.022|name=Franklin|display=inline}}
 | {{sort|001319|}}{{convert|1229|m|abbr=on}} + {{convert|90|m|abbr=on}}
 | tower,<br />weapons development
 | [[W30 (nuclear warhead)|XW-30]] ?
 | style="text-align:center;" | {{sort|000001400|140&nbsp;t}}
 | I-131 venting detected, {{convert|19|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | XW-30 warhead test, fizzled. Retested successfully with ''Franklin Prime'', with more fissile material in the core and different explosives.
 |-
 ! ''Lassen''{{anchor|Lassen}}
 | {{dts|1957|6|5}} 11:45:00.3
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Lassen|display=inline}}
 | {{sort|001745|}}{{convert|1595|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | balloon,<br />weapons development
 | 
 | style="text-align:center;" | {{sort|000006000|600&nbsp;t}}
 | I-131 venting detected, {{convert|100|Ci|GBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_6 />
 | [[Fizzle (nuclear test)|Fizzle]], unboosted all-oralloy small weapon design.
 |-
 ! ''Wilson''{{anchor|Wilson}}
 | {{dts|1957|6|18}} 11:45:00.3
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Wilson|display=inline}}
 | {{sort|001739|}}{{convert|1589|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W45 (nuclear warhead)|XW-45X1]]
 | style="text-align:center;" | {{sort|000100000|10&nbsp;kt}}
 | I-131 venting detected, {{convert|1.5|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | XW-45X1 Swan test, gas-boosted composite pit.
 |-
 ! ''Priscilla''{{anchor|Priscilla}}
 | {{dts|1957|6|24}} 13:30:00.1
 | [[Nevada National Security Site|NTS]] Area 5 {{coord|36.798|-115.9298|name=Priscilla|display=inline}}
 | {{sort|001150|}}{{convert|940|m|abbr=on}} + {{convert|210|m|abbr=on}}
 | balloon,<br />weapons development
 | [[Mark 15 nuclear bomb|Mk-15/39]] primary
 | style="text-align:center;" | {{sort|000370000|37&nbsp;kt}}
 | I-131 venting detected, {{convert|5.8|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | Effects shot with OTS weapon. Similar to that tested in ''Redwing Lacrosse''.
 |-
 ! ''Coulomb-A''{{anchor|Coulomb-A}}
 | {{dts|1957|7|1}} 17:30:??
 | [[Nevada National Security Site|NTS]] Area S3h {{coord|37.053|-116.034|name=Coulomb-A|display=inline}}
 | {{sort|001231|}}{{convert|1231|m|abbr=on}} + 0
 | dry surface,<br />safety experiment
 | [[W31|XW-31]]
 | style="text-align:center;" | {{sort|000000000|no yield}}
 | 
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 /><ref name=LT_44 />
 | Safety experiment, successful.
 |-
 ! ''[[Plumbbob Hood|Hood]]''{{anchor|Hood}}
 | {{dts|1957|7|5}} 11:40:00.1
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Hood|display=inline}}
 | {{sort|001745|}}{{convert|1285|m|abbr=on}} + {{convert|460|m|abbr=on}}
 | balloon,<br />weapons development
 | [[Swan (nuclear primary)|Swan]] primary and Whistle secondary. Full-scale test of device was [[Operation Hardtack I|Hardtack I Maple]] shot.<ref>{{Cite book| isbn = 978-0-9791915-6-5| volume = VI| last = Chuck Hansen| title = Swords of Armageddon| date = 2007|page=392}}</ref>
 | style="text-align:center;" | {{sort|000740000|74&nbsp;kt}}
 | I-131 venting detected, {{convert|11|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | 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''{{anchor|Diablo}}
 | {{dts|1957|7|15}} 11:30:00.1
 | [[Nevada National Security Site|NTS]] Area T2b {{coord|37.1502|-116.1095|name=Diablo|display=inline}}
 | {{sort|001517|}}{{convert|1367|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | Swan
 | style="text-align:center;" | {{sort|000170000|17&nbsp;kt}}
 | I-131 venting detected, {{convert|2.5|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | Very similar to the ''Shasta'' test device. 2 stage. Misfired at first firing attempt three days earlier.
 |-
 ! ''John''{{anchor|John}}
 | {{dts|1957|7|19}} 14:00:04.6
 | Launch from NTS, Areas 1–4, 6–10, Yucca Flat: 10 {{coord|37|-116.0539|name=Launch_John|display=inline}}, elv: {{convert|1220|+|5600|m|abbr=on}};<br />Detonation over [[Nevada National Security Site|NTS]] {{coord|37.1605|-116.0539|name=John|display=inline}}
 | {{sort|006919|}}{{convert|1280|m|abbr=on}} + {{convert|5639|m|abbr=on}}
 | Air launched rocket, weapon effect
 | [[W25 (nuclear warhead)|W-25]]
 | style="text-align:center;" | {{sort|000020000|2&nbsp;kt}}
 | I-131 venting detected, 6.1MCi?
 | <ref name=LT_1 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | Proof test of ''[[AIR-2 Genie|AIR-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''{{anchor|Kepler}}
 | {{dts|1957|7|24}} 11:49:59.9
 | [[Nevada National Security Site|NTS]] Area 4 {{coord|37.09549|-116.10354|name=Kepler|display=inline}}
 | {{sort|001468|}}{{convert|1318|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | [[XW-35]] primary?
 | style="text-align:center;" | {{sort|000100000|10&nbsp;kt}}
 | I-131 venting detected, {{convert|1.7|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | ICBM warhead, similar to ''Hardtack I/Koa''.
 |-
 ! ''Owens''{{anchor|Owens}}
 | {{dts|1957|7|25}} 13:29:59.7
 | [[Nevada National Security Site|NTS]] Area B9b ~ {{coord|37.1347|-116.0417|name=Owens|display=inline}}
 | {{sort|001410|}}{{convert|1260|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | balloon,<br />weapons development
 | [[XW-51]] ?
 | style="text-align:center;" | {{sort|000097000|9.7&nbsp;kt}}
 | I-131 venting detected, {{convert|1.7|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | Very small boosted [[plutonium]] device, XW-51 progenitor.
 |-
 ! ''{{visible anchor|Pascal-A}}''
 | {{dts|1957|7|26}} 08:00:00.0
 | [[Nevada National Security Site|NTS]] Area U3j {{coord|37.05175|-116.03415|name=Pascal-A|display=inline}}
 | {{sort|001052|}}{{convert|1202|m|abbr=on}}–{{convert|150|m|abbr=on}}
 | underground shaft,<br />safety experiment
 | 
 | style="text-align:center;" | {{sort|000000550|55&nbsp;t}}
 | I-131 venting detected, {{convert|10|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | Originally ''Galileo A''. One-point safety experiment, failure. Expected yield was less than 1&nbsp;kg. A concrete cylinder perhaps {{convert|2|m|abbr=on}} thick {{convert|100|m|abbr=on}} up the tube disappeared.
 |-
 ! ''Stokes''{{anchor|Stokes}}
 | {{dts|1957|8|7}} 12:25:00.2
 | [[Nevada National Security Site|NTS]] Area B7b ~ {{coord|37.0866|-116.0245|name=Stokes|display=inline}}
 | {{sort|001710|}}{{convert|1250|m|abbr=on}} + {{convert|460|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W30 (nuclear warhead)|XW-30]]
 | style="text-align:center;" | {{sort|000190000|19&nbsp;kt}}
 | I-131 venting detected, {{convert|2.8|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | [[Tactical Atomic Demolition Munition]] (TADM) and Talos SAM warhead.
 |-
 ! ''Saturn''{{anchor|Saturn}}
 | {{dts|1957|8|10}} 00:59:55.1
 | [[Nevada National Security Site|NTS]] Area U12c.02 {{coord|37.19355|-116.20059|name=Saturn|display=inline}}
 | {{sort|001191|}}{{convert|1231|m|abbr=on}}–{{convert|39.01|m|abbr=on}}
 | tunnel,<br />safety experiment
 | [[W45 (nuclear warhead)|XW-45X1]]
 | style="text-align:center;" | {{sort|000000000|50&nbsp;kg}}
 | 
 | <ref name=LT_1 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 /><ref name=LT_34 />
 | [[Nuclear weapons design#One-point safety|One-point safety experiment]]; first shot in a Rainier tunnel.
 |-
 ! ''Shasta''{{anchor|Shasta}}
 | {{dts|1957|8|18}} 12:00:00.0
 | [[Nevada National Security Site|NTS]] Area 2a {{coord|37.128|-116.1073|name=Shasta|display=inline}}
 | {{sort|001489|}}{{convert|1339|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | Swan
 | style="text-align:center;" | {{sort|000170000|17&nbsp;kt}}
 | I-131 venting detected, {{convert|2.5|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | 2 stage thermonuclear design.
 |-
 ! ''Doppler''{{anchor|Doppler}}
 | {{dts|1957|8|23}} 12:30:00.1
 | [[Nevada National Security Site|NTS]] Area B7b ~ {{coord|37.0866|-116.0245|name=Doppler|display=inline}}
 | {{sort|001742|}}{{convert|1282|m|abbr=on}} + {{convert|460|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W34 (nuclear warhead)|XW-34]] ?
 | style="text-align:center;" | {{sort|000110000|11&nbsp;kt}}
 | I-131 venting detected, {{convert|1.7|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | LASL gas boosted implosion device, possible XW-34 test.
 |-
 ! ''Pascal-B''{{anchor|Pascal-B}}
 | {{dts|1957|8|27}} 22:35:00.0
 | [[Nevada National Security Site|NTS]] Area U3d {{coord|37.04903|-116.0347|name=Pascal-B|display=inline}}
 | {{sort|001079|}}{{convert|1229|m|abbr=on}}–{{convert|150|m|abbr=on}}
 | underground shaft,<br />safety experiment
 | 
 | style="text-align:center;" | {{sort|000003000|300&nbsp;t}}
 | 
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | Shaft safety experiment, failed. Sent the shaft cap weighing several hundred pounds (1 ton) at velocity very roughly pre-calculated as {{convert|66|km/s|abbr=on}}; popular claims of it reaching space are disputed, see section above.
|-
 ! ''Franklin Prime''{{anchor|Franklin Prime}}
 | {{dts|1957|8|30}} 12:39:59.9
 | [[Nevada National Security Site|NTS]] Area B7b ~ {{coord|37.0866|-116.0245|name=Franklin Prime|display=inline}}
 | {{sort|001512|}}{{convert|1282|m|abbr=on}} + {{convert|230|m|abbr=on}}
 | balloon,<br />weapons development
 | 
 | style="text-align:center;" | {{sort|000047000|4.7&nbsp;kt}}
 | I-131 venting detected, {{convert|690|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | Retest of ''Franklin'' with more U-235.
 |-
 ! ''Smoky''{{anchor|Smoky}}
 | {{dts|1957|8|31}} 12:30:00.0
 | [[Nevada National Security Site|NTS]] Area T2c {{coord|37.18712|-116.06887|name=Smoky|display=inline}}
 | {{sort|001577|}}{{convert|1367|m|abbr=on}} + {{convert|210|m|abbr=on}}
 | tower,<br />weapons development
 | [[B41 nuclear bomb|TX-41]] primary
 | style="text-align:center;" | {{sort|000440000|44&nbsp;kt}}
 | I-131 venting detected, {{convert|6.4|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 /><ref name=LT_178 />
 | 2 stages of 3 stage thermonuke, similar to ''Redwing/Zuni'' and ''Tewa''. Desert Rock VII; 3000 servicemen irradiated; 10 of 4 expected leukemia cases in the 80s. Last pristine air-drop location at the NTS.
 |-
 ! ''Galileo''{{anchor|Galileo}}
 | {{dts|1957|9|2}} 12:40:00.0
 | [[Nevada National Security Site|NTS]] Area T1 {{coord|37.053|-116.1034|name=Galileo|display=inline}}
 | {{sort|001444|}}{{convert|1294|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | 
 | style="text-align:center;" | {{sort|000110000|11&nbsp;kt}}
 | I-131 venting detected, {{convert|1.9|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | LASL diagnostic/exploratory test of boosted fission device. Desert Rock VIII.
 |-
 ! ''Wheeler''{{anchor|Wheeler}}
 | {{dts|1957|9|6}} 12:45:00.0
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Wheeler|display=inline}}
 | {{sort|001436|}}{{convert|1286|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | balloon,<br />weapons development
 | [[XW-51]] ?
 | style="text-align:center;" | {{sort|000001970|197&nbsp;t}}
 | I-131 venting detected, {{convert|27|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | Retest of redesigned ''Lassen'' device, possible XW-51 air-to-air warhead progenitor.
 |-
 ! ''Coulomb-B''{{anchor|Coulomb-B}}
 | {{dts|1957|9|6}} 20:05:00.6
 | [[Nevada National Security Site|NTS]] Area S3g {{coord|37.0427|-116.0277|name=Coulomb-B|display=inline}}
 | {{sort|001225|}}{{convert|1225|m|abbr=on}} + 0
 | dry surface,<br />safety experiment
 | [[W31|XW-31]]
 | style="text-align:center;" | {{sort|000003000|300&nbsp;t}}
 | I-131 venting detected, {{convert|42|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | One-point safety experiment, high limits test, expected 1&nbsp;kg TNT equivalent, max .2&nbsp;kt - failure.
 |-
 ! ''Laplace''{{anchor|Laplace}}
 | {{dts|1957|9|8}} 12:59:59.8
 | [[Nevada National Security Site|NTS]] Area B7b ~ {{coord|37.0866|-116.0245|name=Laplace|display=inline}}
 | {{sort|001512|}}{{convert|1282|m|abbr=on}} + {{convert|230|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W33 (nuclear weapon)|XW-33]] "Fleegle"
 | style="text-align:center;" | {{sort|000010000|1&nbsp;kt}}
 | I-131 venting detected, {{convert|140|kCi|TBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_6 />
 | Oralloy gun-type device, for a nuclear artillery shell. The third of only four gun-type weapons, with ''Little Boy, Grable'' and ''Aardvark''.
 |-
 ! ''Fizeau''{{anchor|Fizeau}}
 | {{dts|1957|9|14}} 16:44:59.8
 | [[Nevada National Security Site|NTS]] Area T3b {{coord|37.0336|-116.0323|name=Fizeau|display=inline}}
 | {{sort|001370|}}{{convert|1220|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | [[W34 (nuclear warhead)|XW-34]] ?
 | style="text-align:center;" | {{sort|000110000|11&nbsp;kt}}
 | I-131 venting detected, {{convert|1.7|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | LASL boosted fission device. Possibly a test of the XW-34 depth bomb.
 |-
 ! ''Newton''{{anchor|Newton}}
 | {{dts|1957|9|16}} 12:49:59.9
 | [[Nevada National Security Site|NTS]] Area B7a ~ {{coord|37.0866|-116.0245|name=Newton|display=inline}}
 | {{sort|001742|}}{{convert|1282|m|abbr=on}} + {{convert|460|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W31|XW-31]]
 | style="text-align:center;" | {{sort|000120000|12&nbsp;kt}}
 | I-131 venting detected, {{convert|2.1|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 />
 | LASL test of XW-31 variant, boosted primary in thermonuclear system mockup. Sounds like a fizzle, but no one says so.
 |-
 ! ''Rainier''{{anchor|Rainier}}
 | {{dts|1957|9|19}} 16:59:59.45
 | [[Nevada National Security Site|NTS]] Area U12b {{coord|37.19573|-116.20404|name=Rainier|display=inline}}
 | {{sort|002022|}}{{convert|2295|m|abbr=on}}–{{convert|272.8|m|abbr=on}}
 | tunnel,<br />weapons development
 | [[W25 (nuclear warhead)|W-25]]
 | style="text-align:center;" | {{sort|000017000|1.7&nbsp;kt}}
 | 
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_24 /><ref name=LT_6 /><ref name=LT_34 />
 | 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''{{anchor|Whitney}}
 | {{dts|1957|9|23}} 12:29:59.8
 | [[Nevada National Security Site|NTS]] Area T2 {{coord|37.1383|-116.1184|name=Whitney|display=inline}}
 | {{sort|001520|}}{{convert|1370|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | tower,<br />weapons development
 | [[W27 warhead|W27]] primary
 | style="text-align:center;" | {{sort|000190000|19&nbsp;kt}}
 | I-131 venting detected, {{convert|2.9|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | Test of boosted Swan primary in W-27 thermonuclear system mockup.
 |-
 ! ''Charleston''{{anchor|Charleston}}
 | {{dts|1957|9|28}} 12:59:59.9
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Charleston|display=inline}}
 | {{sort|001745|}}{{convert|1285|m|abbr=on}} + {{convert|460|m|abbr=on}}
 | balloon,<br />weapons development
 | 
 | style="text-align:center;" | {{sort|000120000|12&nbsp;kt}}
 | I-131 venting detected, {{convert|1.8|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />
 | UCRL test of a small "clean" tactical 2-stage thermonuclear device. Device fizzled when second stage failed to fire.
 |-
 ! ''Morgan''{{anchor|Morgan}}
 | {{dts|1957|10|7}} 13:00:00.1
 | [[Nevada National Security Site|NTS]] Area B9a ~ {{coord|37.1347|-116.0417|name=Morgan|display=inline}}
 | {{sort|001435|}}{{convert|1285|m|abbr=on}} + {{convert|150|m|abbr=on}}
 | balloon,<br />weapons development
 | [[W45 (nuclear warhead)|XW-45X1]] Swan/<wbr>Flamingo
 | style="text-align:center;" | {{sort|000080000|8&nbsp;kt}}
 | I-131 venting detected, {{convert|1.2|MCi|PBq|abbr=on}}
 | <ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />
 | 
 |}

==Gallery==
<gallery class="center" widths="220">
File:Plumbob Hood.gif|[[Plumbbob Hood|Plumbbob-''Hood'']], 74-kilotons.
File:Plumbbob Fizeau.gif|Plumbbob-''Fizeau'', 11-kilotons.
File:Plumbbob galileo.gif|Plumbbob-''Galileo'', 11-kilotons.
File:Coulomb-B.gif|Plumbbob-''Coulomb-B''.
File:PlumbbobRainier.gif|Plumbbob-''Rainier'', 1.7-kilotons.
File:Plumbbob Rainier Device.jpg|Plumbbob-''Rainier'' device.
File:Plumbbob John.gif|Plumbbob-''John'', 2-kilotons.
File:Plumbbob John 003.jpg|Plumbbob-''John'' launch, via F-89.
</gallery>

==See also==

*[[Lists of nuclear disasters and radioactive incidents]]
*[[Totskoye nuclear exercise]]

==Notes==

{{Reflist|group=note}}

==References==

{{Reflist|refs=
<ref name=LT_1>{{citation| last1=Yang| first1=Xiaoping| first2=Robert| last2=North| first3=Carl| last3=Romney| date=August 2000| title=CMR Nuclear Explosion Database (Revision 3)| publisher=SMDC Monitoring Research}}</ref>
<ref name=LT_24>{{citation| last=Hansen| first=Chuck| year=1995| title=The Swords of Armageddon, Vol. 8| publisher=Chukelea Publications| location=Sunnyvale, CA| isbn=978-0-9791915-1-0}}</ref>
<ref name=LT_167>{{citation| first1=P.S.| last1=Harris| first2=C.| last2=Lowery| first3=A.| last3=Nelson| publisher=Defense Nuclear Agency| year=1981| title=Plumbbob Series, 1957 Final| type=DNA6005F| url=http://apps.dtic.mil/dtic/tr/fulltext/u2/a107317.pdf| archive-url=https://web.archive.org/web/20140111020104/http://www.dtic.mil/dtic/tr/fulltext/u2/a107317.pdf| url-status=live| archive-date=January 11, 2014| access-date=January 6, 2014}}</ref>
<ref name=LT_150>{{citation| chapter-url=https://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/i131-report-and-appendix| access-date=January 5, 2014| title=Estimated exposures and thyroid doses received by the American people from Iodine-131 in fallout following Nevada atmospheric nuclear bomb tests| chapter=2| publisher=National Cancer Institute| year=1997| archive-date=February 1, 2017| archive-url=https://web.archive.org/web/20170201125451/https://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/i131-report-and-appendix| url-status=live}}</ref>
<ref name=LT_148>{{citation| url=http://www.nuclearweaponarchive.org/Usa/Tests| access-date=January 6, 2014| last=Sublette| first=Carey| title=Nuclear Weapons Archive}}</ref>
<ref name=LT_6>{{citation| publisher=Department of Energy, Nevada Operations Office| date=December 1, 2000| title=United States Nuclear Tests: July 1945 through September 1992| type=DOE/NV-209 REV15| location=Las Vegas, NV| url=http://www.nv.doe.gov/library/publications/historical/DOENV_209_REV15.pdf| access-date=December 18, 2013| url-status=dead| archive-url=https://web.archive.org/web/20061012160826/http://www.nv.doe.gov/library/publications/historical/DOENV_209_REV15.pdf| archive-date=October 12, 2006}}</ref>
<ref name=LT_44>{{citation| last1=Norris| first1=Robert Standish| first2=Thomas B.| last2=Cochran| date=February 1, 1994| title=United States nuclear tests, July 1945 to 31 December 1992 (NWD 94-1)| journal=Nuclear Weapons Databook Working Paper| publisher=Natural Resources Defense Council| location=Washington, DC| url=http://docs.nrdc.org/nuclear/files/nuc_02019401a_121.pdf| access-date=October 26, 2013| url-status=dead| archive-url=https://web.archive.org/web/20131029194805/http://docs.nrdc.org/nuclear/files/nuc_02019401a_121.pdf| archive-date=October 29, 2013}}</ref>
<ref name=LT_34>{{citation| publisher=Sandia National Laboratories| date=July 1, 1994| title=Official list of underground nuclear explosions| url=http://nuclearweaponarchive.org/Usa/Tests/Nevada.html| access-date=December 18, 2013}}</ref>
<ref name=LT_178>{{citation| publisher=Defense Nuclear Agency, Department of Defense| location=Washington, DC| year=1981| title=Shot Smoky: A Test of the Plumbbob Series, 31 August 1957 (DNA-6004F)| hdl=2027/uiug.30112075684347}}</ref>
}}

==External links==

{{Commons|Operation Plumbbob}}
* Video clips: [http://www.criticalpast.com/video/65675046804_Nuclear-test_desert-floor_obscured-by-brightness_fireball-and-smoke Historic color footage of shot "Owens"], {{YouTube|szbb00ncNNs|Rainier}} during Operation Plumbbob
* [http://nuclearweaponarchive.org/Usa/Tests/Plumbob.html Plumbbob page] on the Nuclear Weapons Archive (also refers to [[Operation Plumbbob#Missing steel bore cap|manhole cover issue mentioned above]]).

{{Nuclear weapons tests of the United States}}
{{Authority control}}

[[Category:Explosions in 1957]]
[[Category:Nevada Test Site nuclear explosive tests|Plumbbob]]
[[Category:Radiation health effects research]]
[[Category:1957 in military history]]
[[Category:1957 in Nevada]]
[[Category:1957 in the environment]]