Operation Plumbbob

Template:Short description Template:Use mdy dates Template:Infobox nuclear weapons test Template:GeoGroup 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.<ref name=LT_1 />

BackgroundEdit

The operation consisted of 29 explosions, of which only two did not produce any nuclear yield. Twenty-one laboratories and government agencies were involved. While most Operation Plumbbob tests contributed to the development of warheads for intercontinental and intermediate range missiles, they also tested air defense and 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. Air Force, Army, Navy and Marines participated in exercises Desert Rock VII and 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 battlefield.

Almost 1,200 pigs were subjected to bio-medical experiments and blast-effects studies during Operation Plumbbob. On shot Priscilla (37 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 thermal radiation. As shown and reported in the PBS documentary Dark Circle, the pigs survived, but with third-degree burns to 80% of their bodies.<ref>Template:Cite AV media</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 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 plane crash.

Template:Anchor The John shot on July 19, 1957, was the only test of the Air Force's AIR-2A Genie rocket with a nuclear warhead.<ref>Template:Cite news</ref> It was fired from an 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 Template:Convert altitude, with the idea of demonstrating the possibility of the use of the weapon over civilian populations without ill effects.<ref>Template:Cite news</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>Template:Cite news</ref> The videographer, Akira "George" Yoshitake, died in 2013.<ref>Template:Cite news</ref>

Template:Anchor 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 kt could be detected around the world by seismologists using ordinary seismic instruments. The Rainier test became the prototype for larger and more powerful underground tests.

Template:Anchor 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>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Missing steel bore capEdit

Template:Anchor 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 Template:Convert 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">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> a Template:Convert 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">{{#invoke:citation/CS1|citation |CitationClass=web }}</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 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>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

List of testsEdit

Template:See also

United States' Plumbbob series tests and detonations
Name	Date time (UT) (local: PST, −8 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 {{#invoke:citation/CS1\|citation	CitationClass=web }}</ref>	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>	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>	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> 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>	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>	Yield<ref group=note>Estimated energy yield in tons or kilotons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).</ref>	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>	References	Notes
BoltzmannTemplate:Anchor	Template:Dts 11:55:00.2	NTS Area 7c Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	XW-40	Template:Sort	I-131 venting detected, Template:Convert	<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.
FranklinTemplate:Anchor	Template:Dts 11:54:59.9	NTS Area T3 Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	XW-30 ?	Template:Sort	I-131 venting detected, Template:Convert	<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.
LassenTemplate:Anchor	Template:Dts 11:45:00.3	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development		Template:Sort	I-131 venting detected, Template:Convert	<ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_6 />	Fizzle, unboosted all-oralloy small weapon design.
WilsonTemplate:Anchor	Template:Dts 11:45:00.3	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-45X1	Template:Sort	I-131 venting detected, Template:Convert	<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.
PriscillaTemplate:Anchor	Template:Dts 13:30:00.1	NTS Area 5 Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	Mk-15/39 primary	Template:Sort	I-131 venting detected, Template:Convert	<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-ATemplate:Anchor	Template:Dts 17:30:??	NTS Area S3h Template:Coord	Template:Sort Template:Convert + 0	dry surface, safety experiment	XW-31	Template:Sort		<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.
HoodTemplate:Anchor	Template:Dts 11:40:00.1	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	Swan primary and Whistle secondary. Full-scale test of device was Hardtack I Maple shot.<ref>Template:Cite book</ref>	Template:Sort	I-131 venting detected, Template:Convert	<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.
DiabloTemplate:Anchor	Template:Dts 11:30:00.1	NTS Area T2b Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	Swan	Template:Sort	I-131 venting detected, Template:Convert	<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.
JohnTemplate:Anchor	Template:Dts 14:00:04.6	Launch from NTS, Areas 1–4, 6–10, Yucca Flat: 10 Template:Coord, elv: Template:Convert; Detonation over NTS Template:Coord	Template:Sort Template:Convert + Template:Convert	Air launched rocket, weapon effect	W-25	Template:Sort	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-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.
KeplerTemplate:Anchor	Template:Dts 11:49:59.9	NTS Area 4 Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	XW-35 primary?	Template:Sort	I-131 venting detected, Template:Convert	<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.
OwensTemplate:Anchor	Template:Dts 13:29:59.7	NTS Area B9b ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-51 ?	Template:Sort	I-131 venting detected, Template:Convert	<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.
Template:Visible anchor	Template:Dts 08:00:00.0	NTS Area U3j Template:Coord	Template:Sort Template:Convert–Template:Convert	underground shaft, safety experiment		Template:Sort	I-131 venting detected, Template:Convert	<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 kg. A concrete cylinder perhaps Template:Convert thick Template:Convert up the tube disappeared.
StokesTemplate:Anchor	Template:Dts 12:25:00.2	NTS Area B7b ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-30	Template:Sort	I-131 venting detected, Template:Convert	<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.
SaturnTemplate:Anchor	Template:Dts 00:59:55.1	NTS Area U12c.02 Template:Coord	Template:Sort Template:Convert–Template:Convert	tunnel, safety experiment	XW-45X1	Template:Sort		<ref name=LT_1 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 /><ref name=LT_34 />	One-point safety experiment; first shot in a Rainier tunnel.
ShastaTemplate:Anchor	Template:Dts 12:00:00.0	NTS Area 2a Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	Swan	Template:Sort	I-131 venting detected, Template:Convert	<ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_148 /><ref name=LT_6 />	2 stage thermonuclear design.
DopplerTemplate:Anchor	Template:Dts 12:30:00.1	NTS Area B7b ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-34 ?	Template:Sort	I-131 venting detected, Template:Convert	<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-BTemplate:Anchor	Template:Dts 22:35:00.0	NTS Area U3d Template:Coord	Template:Sort Template:Convert–Template:Convert	underground shaft, safety experiment		Template:Sort		<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 Template:Convert; popular claims of it reaching space are disputed, see section above.
Franklin PrimeTemplate:Anchor	Template:Dts 12:39:59.9	NTS Area B7b ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development		Template:Sort	I-131 venting detected, Template:Convert	<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.
SmokyTemplate:Anchor	Template:Dts 12:30:00.0	NTS Area T2c Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	TX-41 primary	Template:Sort	I-131 venting detected, Template:Convert	<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.
GalileoTemplate:Anchor	Template:Dts 12:40:00.0	NTS Area T1 Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development		Template:Sort	I-131 venting detected, Template:Convert	<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.
WheelerTemplate:Anchor	Template:Dts 12:45:00.0	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-51 ?	Template:Sort	I-131 venting detected, Template:Convert	<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-BTemplate:Anchor	Template:Dts 20:05:00.6	NTS Area S3g Template:Coord	Template:Sort Template:Convert + 0	dry surface, safety experiment	XW-31	Template:Sort	I-131 venting detected, Template:Convert	<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 kg TNT equivalent, max .2 kt - failure.
LaplaceTemplate:Anchor	Template:Dts 12:59:59.8	NTS Area B7b ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-33 "Fleegle"	Template:Sort	I-131 venting detected, Template:Convert	<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.
FizeauTemplate:Anchor	Template:Dts 16:44:59.8	NTS Area T3b Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	XW-34 ?	Template:Sort	I-131 venting detected, Template:Convert	<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.
NewtonTemplate:Anchor	Template:Dts 12:49:59.9	NTS Area B7a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-31	Template:Sort	I-131 venting detected, Template:Convert	<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.
RainierTemplate:Anchor	Template:Dts 16:59:59.45	NTS Area U12b Template:Coord	Template:Sort Template:Convert–Template:Convert	tunnel, weapons development	W-25	Template:Sort		<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.
WhitneyTemplate:Anchor	Template:Dts 12:29:59.8	NTS Area T2 Template:Coord	Template:Sort Template:Convert + Template:Convert	tower, weapons development	W27 primary	Template:Sort	I-131 venting detected, Template:Convert	<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.
CharlestonTemplate:Anchor	Template:Dts 12:59:59.9	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development		Template:Sort	I-131 venting detected, Template:Convert	<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.
MorganTemplate:Anchor	Template:Dts 13:00:00.1	NTS Area B9a ~ Template:Coord	Template:Sort Template:Convert + Template:Convert	balloon, weapons development	XW-45X1 Swan/Flamingo	Template:Sort	I-131 venting detected, Template:Convert	<ref name=LT_1 /><ref name=LT_167 /><ref name=LT_150 /><ref name=LT_24 /><ref name=LT_6 />