Operation Hardtack I

Operation Hardtack I

Hardtack I Oak, an 8.9 megaton explosion.
Information
Country United States
Test site Bogallua (Alice), Enewetak Atoll; Eninmen (Tare), Bikini Atoll; Enjebi (Janet), Enewetak Atoll; Johnston Island, Johnston Atoll; Namu (Charlie), Bikini Atoll; Pacific Proving Grounds; Pokon (Irvin), Enewetak Atoll; Runit (Yvonne), Enewetak Atoll; Teiter (Gene), Enewetak Atoll; Yurochi aka Irioj (Dog), Bikini Atoll
Period 1958
Number of tests 35
Test type air drop, balloon, barge, dry surface, high alt rocket (3080 km), underwater
Max. yield 9.3 megatons of TNT (39 PJ)
Navigation
Previous test series Project 58/58A
Next test series Operation Argus

Operation Hardtack I[1] was a series of 35 nuclear tests conducted by the United States in 1958 at the Pacific Proving Grounds. These tests followed the Project 58/58A series and preceded the Operation Argus series.

Operation Newsreel was a series of three high-altitude nuclear tests conducted as part of Hardtack I. The individual tests in the series were Orange, Teak and Yucca.[1]

Aerial shot of the explosion during Hardtack I Poplar

Tests

United States' Hardtack I series tests and detonations
Name [note 1] Date time (UT) Local time zone [note 2][2] Location [note 3] Elevation + height [note 4] Delivery [note 5]
Purpose [note 6]
Device [note 7] Yield [note 8] Fallout [note 9] References Notes
Yucca 28 April 1958 02:40:00.3 edst (12 hrs)
Pacific Proving Grounds 12°37′01″N 167°01′30″E / 12.617°N 167.025°E 0 + 26.21 kilometres (16.29 mi) balloon,
weapon effect
W-25 1.7 kt [1][3][4][5][6] ABM development - part of Operation Newsreel (high altitude tests). Fired "about 85 nmi (157 km; 98 mi) northwest of Bikini".
Cactus 5 May 1958 18:15:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°33′09″N 162°20′50″E / 11.55255°N 162.34727°E 1 m (3 ft 3 in) + 1 m (3 ft 3 in) dry surface,
weapons development
Mk-43 primary 18 kt [1][3][4][5][6] LASL test of a MK-43 primary in a thermonuclear system mockup. Similar to Elder. 596 ft (182 m) crater southwest of the Redwing Lacrosse crater; crater later became the Cactus Dome.
Fir 11 May 1958 17:50:00.1 MHT (11 hrs)
Namu (Charlie), Bikini Atoll 11°41′27″N 165°16′24″E / 11.6908°N 165.2733°E 0 + 3 m (9.8 ft) barge,
weapons development
1.4 Mt [1][3][5][6] Clean 2-stage TN device, only 90 kt fission, 93.4% fusion yield.
Butternut 11 May 1958 18:15:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′19″N 162°20′37″E / 11.53859°N 162.34367°E 0 + 3 m (9.8 ft) barge,
weapons development
TX-46 primary ? 81 kt [1][3][5][6] TX-46 primary test, similar to Oak and Yellowwood.
Koa 12 May 1958 18:30:00.1 MHT (11 hrs)
Teiter (Gene), Enewetak Atoll 11°40′12″N 162°11′54″E / 11.66997°N 162.19847°E 2 m (6 ft 7 in) + 0.81 m (2 ft 8 in) dry surface,
weapons development
XW-35 1.4 Mt [1][3][5][6] XW-35 ICBM warhead test.
Wahoo 16 May 1958 01:30:00.5 MHT (11 hrs)
Pokon (Irvin), Enewetak Atoll 11°19′35″N 162°09′47″E / 11.32646°N 162.16309°E 0 - 150 m (490 ft) underwater,
weapon effect
Mk-7 9 kt [1][3][5][6] Mk-7 deep water effects test, water depth 3,200 ft (980 m).
Holly 20 May 1958 18:30:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′25″N 162°21′01″E / 11.54029°N 162.35039°E 0 + 4 m (13 ft) barge,
weapons development
XW-31Y3 5.9 kt [1][3][5][6] XW-31Y proof test.
Nutmeg 21 May 1958 21:20:00.2 MHT (11 hrs)
Eninmen (Tare), Bikini Atoll 11°30′13″N 165°22′20″E / 11.50355°N 165.3722°E 0 + 3 m (9.8 ft) barge,
weapons development
early XW-47 ? 25.1 kt [1][3][5][6] 2 stage thermonuclear device, possible W47.
Yellowwood 26 May 1958 02:00:00.1 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′27″N 162°13′18″E / 11.65751°N 162.22168°E 0 + 3 m (9.8 ft) barge,
weapons development
TX-46, became W-53 330 kt [1][3][4][5][6] LASL developmental test of a "clean" TX-46 warhead design. Fizzled, low burn in secondary. Retry in Oak.
Magnolia 26 May 1958 18:00:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′22″N 162°20′54″E / 11.53932°N 162.34841°E 0 + 4 m (13 ft) barge,
weapons development
"Cougar" 57 kt [1][3][5][6] Proof test.
Tobacco 30 May 1958 02:15:00.2 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′38″N 162°13′36″E / 11.66056°N 162.22663°E 0 + 2.7 m (8 ft 10 in) barge,
weapons development
XW-50 11.6 kt [1][3][5][6] Exploratory shot, XW-50 Nike-Zeus prototype, 2nd stage failed to ignite.
Sycamore 31 May 1958 03:00:00.1 MHT (11 hrs)
Namu (Charlie), Bikini Atoll 11°41′50″N 165°16′29″E / 11.69722°N 165.27486°E 0 + 3 m (9.8 ft) barge,
weapons development
TX-41 92 kt [1][3][5][6] "Clean" TX-41 fizzle; predicted yield 5 Mt total, 200 kt fission; low level burning in 2nd stage; similar to Poplar and Pine.
Rose 2 June 1958 18:45:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′21″N 162°20′45″E / 11.53926°N 162.34593°E 0 + 4.5 m (15 ft) barge,
weapons development
XW-49 ? Primary 15 kt [1][3][5][6] Exploratory shot, possible XW-49, 80 kt fusion expected, 2nd stage failed to ignite.
Umbrella 8 June 1958 18:15:00.2 MHT (11 hrs)
Pokon (Irvin), Enewetak Atoll 11°22′30″N 162°11′38″E / 11.37498°N 162.19399°E 0 - 50 m (160 ft) underwater,
weapon effect
Mk-7 8 kt [1][3][4][5][6] Shallow depth underwater shot on lagoon bottom at 150 ft (46 m). Crater 915 m × 6 m (3,002 ft × 20 ft).
Maple 10 June 1958 17:30:00.1 MHT (11 hrs)
Yurochi aka Irioj (Dog), Bikini Atoll 11°41′29″N 165°24′57″E / 11.6915°N 165.41582°E 0 + 3 m (9.8 ft) barge,
weapons development
213 kt [1][3][5][6] "Dirty" 2-stage test, predicted to be 89% fission.
Aspen 14 June 1958 17:30:00.1 MHT (11 hrs)
Namu (Charlie), Bikini Atoll 11°41′27″N 165°16′24″E / 11.6908°N 165.2733°E 0 + 3 m (9.8 ft) barge,
weapons development
XW-47 ? 319 kt [1][3][5][6] Possible XW-47 prototype, 2 stage.
Walnut 14 June 1958 18:30:00.1 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′27″N 162°13′18″E / 11.65751°N 162.22168°E 0 + 2 m (6 ft 7 in) barge,
weapons development
1.5 Mt [1][3][5][6] Thermonuclear prototype development test.
Linden 18 June 1958 03:00:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′26″N 162°21′04″E / 11.54061°N 162.35106°E 0 + 2.5 m (8 ft 2 in) barge,
weapons development
XW-50 primary ? 11 kt [1][3][5][6] Possible XW-50 primary.
Redwood 27 June 1958 17:30:00.1 MHT (11 hrs)
Yurochi aka Irioj (Dog), Bikini Atoll 11°41′29″N 165°24′57″E / 11.6915°N 165.41582°E 0 + 3 m (9.8 ft) barge,
weapons development
XW-47 ? 412 kt [1][3][5][6] Possible XW-47 prototype, 2-stage, 250 kt fission yield expected; similar to Aspen, Nutmeg, Dogwood devices.
Elder 27 June 1958 18:30:00.1 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′38″N 162°13′36″E / 11.66056°N 162.22663°E 0 + 2.7 m (8 ft 10 in) barge,
weapons development
TX-43 880 kt [1][3][5][6] TX-43 laydown bomb test, 50% fission yield expected, similar to Cactus.
Oak 28 June 1958 19:30:00.1 MHT (11 hrs)
Bogallua (Alice), Enewetak Atoll 11°36′11″N 162°06′09″E / 11.60309°N 162.10259°E 0 + 1.8 m (5 ft 11 in) barge,
weapons development
TX-46/53 8.9 Mt [1][3][4][5][6] Prototype test of the LASL designed TX-46 system. Similar to Butternut and Yellowwood. Crater Template:Conver.
Hickory 29 June 1958 00:00:00.9 MHT (11 hrs)
Eninmen (Tare), Bikini Atoll 11°29′46″N 162°22′15″E / 11.4961°N 162.3708°E 0 + 3 m (9.8 ft) barge,
weapons development
XW-47 primary ? 14 kt [1][3][5][6] Possible XW-47 primary test, similar to Hardtack II Neptune and Titania.
Sequoia 1 July 1958 18:30:00.1 MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′26″N 162°21′04″E / 11.54061°N 162.35106°E 0 + 2 m (6 ft 7 in) barge,
weapons development
XW-50 primary ? 5.2 kt [1][3][5][6] Similar to Hardtack II Otero, test of Hardtack I Pisonia primary.
Cedar 2 July 1958 17:30:00.1 MHT (11 hrs)
Namu (Charlie), Bikini Atoll 11°41′50″N 165°16′29″E / 11.69722°N 165.27486°E 0 + 3.4 m (11 ft) barge,
weapons development
220 kt [1][3][5][6] 2-stage "clean" thermonuke device, predicted fission yield 30 kt.
Dogwood 5 July 1958 18:30:00.2 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′38″N 162°13′36″E / 11.66056°N 162.22663°E 0 + 3 m (9.8 ft) barge,
weapons development
XW-47 ? Piccolo 397 kt [1][3][5][6] Similar to Redwood, Aspen, Nutmeg; possible XW-47 prototype, Piccolo 2nd stage.
Poplar 12 July 1958 03:30:00.1 MHT (11 hrs)
Namu (Charlie), Bikini Atoll 11°41′49″N 165°16′01″E / 11.69704°N 165.26708°E 0 + 3 m (9.8 ft) barge,
weapons development
TX-41 9.3 Mt [1][3][5][6] TX-41 "clean" 2-stage variant; similar to Pine and Sycamore; largest of Hardtack I, and 5th largest U.S. test ever.
Scaevola 14 July 1958 04:00:?? MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′48″N 162°21′07″E / 11.54662°N 162.35199°E 2 m (6 ft 7 in) + 6 m (20 ft) barge,
safety experiment
XW-34 no yield [1][3][5][6][7] XW-34 1-point safety test, successful.
Pisonia 17 July 1958 23:00:?? MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°33′N 162°19′E / 11.55°N 162.31°E 0 + 2 m (6 ft 7 in) barge,
weapons development
XW-50 ? TN, sequoiah pr 255 kt [1][3][5][6][7] Probable prototype XW-50 thermonuclear design, modified Tobacco device, used Sequoia primary.
Juniper 22 July 1958 04:20:00.1 MHT (11 hrs)
Eninmen (Tare), Bikini Atoll 11°30′13″N 165°22′20″E / 11.50355°N 165.3722°E 0 + 3 m (9.8 ft) barge,
weapons development
XW-47 65 kt [1][3][4][5][6] "Most radical UCRL shot", "entirely new concept", last Bikini atmospheric shot, probable XW-47 candidate.
Olive 22 July 1958 20:30:00.2 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′38″N 162°13′36″E / 11.66056°N 162.22663°E 0 + 3 m (9.8 ft) barge,
weapons development
202 kt [1][3][5][6] Concept feasibility test, 2-stage thermonuclear device, established high yield/light weight; weight 100 kg (220 lb) (yield/weight ratio 2 kt/kg).
Pine 26 July 1958 20:30:00.2 MHT (11 hrs)
Enjebi (Janet), Enewetak Atoll 11°39′05″N 162°12′51″E / 11.6513°N 162.21414°E 0 + 3 m (9.8 ft) barge,
weapons development
Mk-41 2 Mt [1][3][5][6] TX-41 "clean" 3-stage variant; similar to Poplar and Sycamore.
Piñon
(canceled)
August 1958 edst (12 hrs)
Pacific Proving Grounds 12°N 162°E / 12°N 162°E 3 m (9.8 ft) + air drop,
weapon effect
unknown yield A proposed international demonstration of a clean thermonuke. Cancelled by President Eisenhower in the runup to the 1958 test moratorium.
Teak 1 August 1958 10:50:05.6 jamt (-11 hrs)
Believed in use during Dominic, Fishbowl,HT I.[8]
Launch from Johnston Island, Johnston Atoll 16°44′01″N 169°31′31″W / 16.73365°N 169.52534°W, elv: 3 + 0 m (9.8 + 0.0 ft);
Detonation over Johnston Island, Johnston Atoll 16°44′38″N 169°32′00″W / 16.7439°N 169.5333°W
N/A + 81.3 kilometres (50.5 mi) high alt rocket (30–80 km),
weapon effect
W-39 3.8 Mt [1][3][5][6] ABM effects test. Miscalculation resulted in detonation directly above launch site. Part of Operation Newsreel (high altitude tests), carried on a Redstone rocket.
Quince 6 August 1958 02:15:?? MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′54″N 162°21′03″E / 11.54828°N 162.35079°E 1 m (3 ft 3 in) + 1 m (3 ft 3 in) dry surface,
weapons development
XW-51 ? no yield [1][3][5][6][7] Probable XW-51 test, fizzle.
Orange 12 August 1958 10:30:08.6 jamt (-11 hrs)
Believed in use during Dominic, Fishbowl,HT I.[8]
Launch from Johnston Island, Johnston Atoll 16°44′01″N 169°31′31″W / 16.73365°N 169.52534°W, elv: 3 + 0 m (9.8 + 0.0 ft);
Detonation over Johnston Island, Johnston Atoll 16°21′30″N 169°32′08″W / 16.3583°N 169.5356°W
N/A + 45.5 kilometres (28.3 mi) high alt rocket (30–80 km),
weapon effect
W39 3.8 Mt [1][3][5][6] ABM effects test, W-39 warhead, part of Operation Newsreel (high altitude tests), carried on a Redstone rocket.
Fig 18 August 1958 04:00:?? MHT (11 hrs)
Runit (Yvonne), Enewetak Atoll 11°32′58″N 162°20′56″E / 11.54955°N 162.34879°E 1 m (3 ft 3 in) + 0.5 m (1 ft 8 in) dry surface,
weapons development
XW-51 ? 20 t [1][5][6][7] Probable XW-51 test, similar to Quince, successful, last atmospheric shot at Enewetak.
  1. 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.
  2. To convert the UT time into standard local, add the number of hours in parentheses to the UT time; for local daylight savings 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. All historical timezone data are derived from here:
  3. 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.
  4. 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.
  5. 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.
  6. Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
  7. 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.
  8. Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
  9. 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.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 1.36 Yang, Xiaoping; North, Robert; Romney, Carl (August 2000), CMR Nuclear Explosion Database (Revision 3), SMDC Monitoring Research
  2. "Timezone Historical Database". iana.com. Retrieved 2014-03-08.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 3.32 3.33 Operation Hardtack, Technical Summary , Table A (ITR-1660-SAN), retrieved 2014-01-06
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Sublette, Carey, Nuclear Weapons Archive, retrieved 2014-01-06
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25 5.26 5.27 5.28 5.29 5.30 5.31 5.32 5.33 5.34 Hansen, Chuck (1995), The Swords of Armageddon, Vol. 8, Sunnyvale, CA: Chukelea Publications, ISBN 978-0-9791915-1-0
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18 6.19 6.20 6.21 6.22 6.23 6.24 6.25 6.26 6.27 6.28 6.29 6.30 6.31 6.32 6.33 6.34 United States Nuclear Tests: July 1945 through September 1992 (DOE/NV-209 REV15), Las Vegas, NV: Department of Energy, Nevada Operations Office, 2000-12-01, retrieved 2013-12-18
  7. 7.0 7.1 7.2 7.3 Norris, Robert Standish; Cochran, Thomas B. (1 February 1994), "United States nuclear tests, July 1945 to 31 December 1992 (NWD 94-1)", Nuclear Weapons Databook Working Paper (Washington, DC: Natural Resources Defense Council), retrieved 2013-10-26
  8. 8.0 8.1 Hoerlin, Herman (October 1976), United States High-Altitude Test Experiences: A Review Emphasizing the Impact on the Environment (LA-6405), Los Alamos Scientific Laboratory, p. 4, retrieved 2014-02-26 Reference for timezone at Johnston Island 1958-1962.

External links

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