Operation Hardtack II[1] was a series of 37 nuclear tests conducted by the United States in 1958 at the Nevada Test Site. These tests followed the Operation Argus series and preceded the Operation Nougat series.
| Operation Hardtack II | |
|---|---|
 Hardtack II Sanford, 4.9 kilotons. | |
| Information | |
| Country | United States |
| Test site |
|
| Period | 1958 |
| Number of tests | 37 |
| Test type | balloon, dry surface, tower, underground shaft, tunnel |
| Max. yield | 22 kilotonnes of TNT (92 TJ) |
| Test series chronology | |
With test moratoriums on the horizon, American weapons labs rushed out many new designs. A hard deadline for testing was set at midnight (0000 hrs), October 31, 1958, as negotiations were set to start that day, and the schedule shows it, with 29 tests executed in October, four of them on the last day. One other test was cancelled because weather delays postponed it across the midnight deadline. After the conclusion of Hardtack II, the United States announced a unilateral testing moratorium, which the Soviet Union joined after two last tests on November 1 and 3.[2] In September 1961, the Soviet Union resumed nuclear testing — including the test of the most powerful nuclear device ever designed, the Tsar Bomba, in October — and the United States followed suit with Operation Nougat.
Nuclear tests
Adams
Adams was planned to be the final test of Hardtack II, but due to unfavorable winds the shot was never fired. The shot was intended to be a balloon test, and had been fully assembled and raised to firing altitude when it was cancelled. After midnight and the start of the moratorium, the device was lowered to the ground and disassembled. The Soviet Union would continue nuclear testing until the 3rd of November.[3]
A 31st October 1958 meeting of the Atomic Energy Commission following the cancellation resulted in the following note:[4]
[General Alfred Starbird] said there will always be a question as to whether the final shot should have been fired in view of its importance [redacted] but he believed that the other considerations were of overriding importance.
List of nuclear tests
| Name [note 1] | Date time (UT) | Local time zone[note 2][5] | Location[note 3] | Elevation + height [note 4] | Delivery [note 5] Purpose [note 6] | Device[note 7] | Yield[note 8] | Fallout[note 9] | References | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| Otero | September 12, 1958 20:00:00.2 | PST (–8 hrs) | NTS Area U3q 37°02′59″N 116°01′57″W / 37.04985°N 116.03255°W | 1,229 m (4,032 ft)–150 m (490 ft) | underground shaft, safety experiment | XW-54 ? | 38 t | Venting detected, 6 kCi (220 TBq) | [1][6][7][8] | 1-point test, failed, device similar to HT-I Sequoia. |
| Bernalillo | September 17, 1958 19:30:00.2 | PST (–8 hrs) | NTS Area U3h (n?) 37°02′58″N 116°02′01″W / 37.04944°N 116.03352°W | 1,229 m (4,032 ft)–150 m (490 ft) | underground shaft, safety experiment | XW-54 | 15 t | Venting detected on site | [1][6][8] | 1-point test, repeat of Otero, also failed. |
| Eddy | September 19, 1958 14:00:00.2 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 150 m (490 ft) | balloon, weapons development | 83 t | Venting detected, 12 kCi (440 TBq) | [1][6][8] | 154 pounds (70 kg) test device successful. | |
| Luna | September 21, 1958 19:00:00.2 | PST (–8 hrs) | NTS Area U3m 37°02′57″N 116°02′04″W / 37.04919°N 116.03447°W | 1,230 m (4,040 ft)–150 m (490 ft) | underground shaft, safety experiment | XW-54 ? | 1.5 t | Venting detected on site | [1][6][7][8] | 1-point test, repeat of Otero/Bernalillo, still unsafe. |
| Mercury | September 23, 1958 22:00:00.0 | PST (–8 hrs) | NTS Area U12f.01 37°11′34″N 116°12′01″W / 37.19274°N 116.20024°W | 2,038 m (6,686 ft)–55.78 m (183.0 ft) | tunnel, safety experiment | XW-47 primary ? | 10 t | [1][6][7][8][9] | 1-point test, declared success despite yield, XW-42 test, similar to Pascal-C and San Juan devices. | |
| Valencia | September 26, 1958 20:00:00.2 | PST (–8 hrs) | NTS Area U3r 37°02′58″N 116°01′50″W / 37.04956°N 116.03057°W | 1,227 m (4,026 ft)–150 m (490 ft) | underground shaft, safety experiment | XW-42 ? | 2 t | Venting detected on site | [1][6][7][8] | 1-point test, declared success despite yield, similar to Pascal-C and San Juan devices. |
| Mars | September 28, 1958 00:00:00.2 | PST (–8 hrs) | NTS Area U12f.02 37°11′35″N 116°12′05″W / 37.19301°N 116.20131°W | 2,082 m (6,831 ft)–42.67 m (140.0 ft) | tunnel, safety experiment | XW-48 | 13 t | Venting detected on site | [1][6][7][8][9] | 1-point test, similar to Tamalpais and Ceres. |
| Mora | September 29, 1958 14:05:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-54 Gnat | 2 kt | Venting detected, 340 kCi (13,000 TBq) | [1][6][8] | Full yield test of device similar to Otero et al., fizzled. |
| Hidalgo | October 5, 1958 14:10:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 110 m (360 ft) | balloon, safety experiment | Moccasin | 77 t | Venting detected, 11 kCi (410 TBq) | [1][6][8] | This 1-point test failed; similar to Coulomb-C. |
| Colfax | October 5, 1958 16:15:00.2 | PST (–8 hrs) | NTS Area U3k 37°02′56″N 116°02′06″W / 37.04882°N 116.03491°W | 1,229 m (4,032 ft)–107 m (351 ft) | underground shaft, safety experiment | XW-54 Gnat | 5.5 t | Venting detected, 240 kCi (8,900 TBq) | [1][6][8] | 1-point test of device similar to Otero et al., failed. Unstemmed shaft. |
| Tamalpais | October 8, 1958 22:00:00.13 | PST (–8 hrs) | NTS Area U12b.02 37°11′43″N 116°12′05″W / 37.19525°N 116.20133°W | 2,152 m (7,060 ft)–124.05 m (407.0 ft) | tunnel, weapons development | XW-48 | 72 t | [1][6][7][8][9] | Full yield test, similar to Mars and Ceres. | |
| Quay | October 10, 1958 14:30:00.1 | PST (–8 hrs) | NTS Area 7c 37°05′41″N 116°01′28″W / 37.0947°N 116.0245°W | 1,294 m (4,245 ft) + 30 m (98 ft) | tower, weapons development | XW-50 ? | 79 t | Venting detected, 200 Ci (7,400 GBq) | [1][6][7][8] | Concept feasibility test, similar to HT-I Linden. |
| Lea | October 13, 1958 13:20:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-54 Gnat ? | 1.4 kt | Venting detected, 240 kCi (8,900 TBq) | [1][6][7][8][10] | Full yield test of device similar to Otero et al., fizzled. |
| Neptune | October 14, 1958 18:00:00.2 | PST (–8 hrs) | NTS Area U12c.03 37°11′38″N 116°12′02″W / 37.19381°N 116.20057°W | 2,080 m (6,820 ft)–30.02 m (98.5 ft) | tunnel, safety experiment | XW-47 | 115 t | Venting detected on site | [1][6][8][9] | 1-point test, failed, similar to HT-I Hickory and HT-II Titania. First NTS subsidence crater at Rainier despite low yield and depth buried. |
| Hamilton | October 15, 1958 16:00:00.2 | PST (–8 hrs) | NTS Area 5 36°48′08″N 115°55′59″W / 36.8022°N 115.9331°W | 940 m (3,080 ft) + 15 m (49 ft) | tower, weapons development | XW-51 ? Quail | 1.2 t | Venting detected, 200 Ci (7,400 GBq) | [1][6][7][8] | Davy Crockett prototype test, fizzled, extremely small device (16 kg (35 lb)). |
| Logan | October 16, 1958 06:00:00.14 | PST (–8 hrs) | NTS Area A12e.02 37°11′02″N 116°12′07″W / 37.18399°N 116.20206°W | 2,155 m (7,070 ft)–283.58 m (930.4 ft) | tunnel, weapons development | 5 kt | [1][6][8][9] | ABM warhead test, small (28.6 kg (63 lb), 28 cm × 29 cm (11 in × 11 in)) kiloton-range device, successful. | ||
| Dona Ana | October 16, 1958 14:20:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 150 m (490 ft) | balloon, weapons development | XW-54 Gnat | 37 t | Venting detected, 6 kCi (220 TBq) | [1][6][8] | Low yield test, similar to Otero et al. |
| Vesta | October 17, 1958 23:00:00.2 | PST (–8 hrs) | NTS Area S9e 37°07′21″N 116°02′05″W / 37.1226°N 116.0347°W | 1,294 m (4,245 ft) + 0 | dry surface, safety experiment | XW-47 primary | 24 t | Venting detected, 4 kCi (150 TBq) | [1][6][7][8] | 1-point test, failed, similar to Wrangell, Oberon, Sanford. |
| Rio Arriba | October 18, 1958 14:25:00.1 | PST (–8 hrs) | NTS Area 3s 37°02′28″N 116°01′36″W / 37.0411°N 116.0267°W | 1,224 m (4,016 ft) + 20 m (66 ft) | tower, weapons development | Mk-7 | 90 t | Venting detected, 120 kCi (4,400 TBq) | [1][6][7][8] | Low yield Mk-7, successful, fired on wooden tower. |
| San Juan | October 20, 1958 14:30:00.2 | PST (–8 hrs) | NTS Area U3p 37°02′59″N 116°02′00″W / 37.04976°N 116.03325°W | 1,229 m (4,032 ft)–71 m (233 ft) | underground shaft, safety experiment | XW-42 ? | no yield | [1][6][7][8] | 1-point test, successful, safe design extrapolated from Pascal-C and HT-II Valencia. Unstemmed shaft. | |
| Socorro | October 22, 1958 13:30:00.2 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 440 m (1,440 ft) | balloon, weapons development | XW-54 Gnat ? | 6 kt | Venting detected, 1,000 kCi (37,000 TBq) | [1][6][7][8][10] | Full yield test of XW-54 primary, successful, similar to Otero et al. |
| Wrangell | October 22, 1958 16:50:00.1 | PST (–8 hrs) | NTS Area 5 36°47′53″N 115°55′47″W / 36.798°N 115.9298°W | 940 m (3,080 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-47 Canary ? | 115 t | Venting detected, 17 kCi (630 TBq) | [1][6][7][8] | Full yield test fizzle, similar to Vesta, Oberon, Sanford. |
| Oberon | October 22, 1958 20:30:?? | PST (–8 hrs) | NTS Area 8a 37°10′58″N 116°04′09″W / 37.1829°N 116.0691°W | 1,355 m (4,446 ft) + 8 m (26 ft) | tower, safety experiment | XW-47 primary Canary ? | no yield | Venting detected, 17 kCi (630 TBq) | [1][6][7][8][11] | 1-point test, successful, similar to Vesta, Wrangell, Sanford. |
| Rushmore | October 22, 1958 23:40:00.1 | PST (–8 hrs) | NTS Area B9a ~ 37°08′05″N 116°02′30″W / 37.1347°N 116.0417°W | 1,285 m (4,216 ft) + 150 m (490 ft) | balloon, weapons development | XW-47 primary Canary ? | 188 t | [1][6][7][8] | Low yield test, fizzled, similar to Mercury, Neptune, Titania. | |
| Catron | October 24, 1958 15:00:00.2 | PST (–8 hrs) | NTS Area 3t 37°02′34″N 116°01′40″W / 37.0427°N 116.0277°W | 1,225 m (4,019 ft) + 20 m (66 ft) | tower, safety experiment | XW-54 Gnat | 21 t | Venting detected, 4 kCi (150 TBq) | [1][6][8] | 1-point test, similar to Mora, failed, fired on wooden tower. |
| Juno | October 24, 1958 16:01:00.2 | PST (–8 hrs) | NTS Area S9f 37°07′25″N 116°02′16″W / 37.12361°N 116.03776°W | 1,287 m (4,222 ft) + 0 | dry surface, safety experiment | Logan | 1.7 t | [1][6][7][8] | 1-point test to determine safety limits. | |
| Ceres | October 26, 1958 04:00:00.2 | PST (–8 hrs) | NTS Area 8b 37°10′53″N 116°04′09″W / 37.1814°N 116.0691°W | 1,350 m (4,430 ft) + 10 m (33 ft) | tower, safety experiment | XW-48 AFAP | 700 kg | [1][6][7][8] | 1-point test of atomic artillery shell, similar to Tamalpais and Mars. | |
| Sanford | October 26, 1958 10:20:00.1 | PST (–8 hrs) | NTS Area 5 36°47′53″N 115°55′47″W / 36.798°N 115.9298°W | 940 m (3,080 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-47 primary Canary ? | 4.9 kt | Venting detected, 750 kCi (28,000 TBq) | [1][6][7][8] | Full yield test, successful, similar to Vesta, Oberon, Wrangell. |
| De Baca | October 26, 1958 16:00:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-54 Gnat | 2.2 kt | Venting detected, 380 kCi (14,000 TBq) | [1][6][8][10] | Full yield test, disappointing yield, similar to Catron and Mora. |
| Chavez | October 27, 1958 14:30:?? | PST (–8 hrs) | NTS Area 3u 37°02′39″N 116°01′50″W / 37.0443°N 116.0305°W | 1,225 m (4,019 ft) + 16 m (52 ft) | tower, safety experiment | XW-54 Gnat | 600 kg | Venting detected, 100 Ci (3,700 GBq) | [1][6][7][8][11] | 1-point test of device similar to De Baca, failed, fired on wooden tower. |
| Evans | October 29, 1958 00:00:00.15 | PST (–8 hrs) | NTS Area U12b.04 37°11′41″N 116°12′20″W / 37.19477°N 116.20563°W | 2,282 m (7,487 ft)–256.03 m (840.0 ft) | tunnel, weapons development | XW-47 primary Canary ? | 55 t | Venting detected on site | [1][6][7][8][9] | Full yield test fizzle, similar to Blanca. |
| Mazama | October 29, 1958 11:20:?? | PST (–8 hrs) | NTS Area 9 37°07′35″N 116°02′31″W / 37.12648°N 116.04196°W | 1,282 m (4,206 ft) + 15 m (49 ft) | tower, weapons development | no yield | [1][6][7][8][11] | Fizzle. | ||
| Humboldt | October 29, 1958 14:45:00.1 | PST (–8 hrs) | NTS Area 3v 37°02′52″N 116°01′32″W / 37.0477°N 116.0256°W | 1,228 m (4,029 ft) + 10 m (33 ft) | tower, weapons development | XW-51 ? | 7.8 t | Venting detected, 1 kCi (37 TBq) | [1][6][7][8] | Repeat of Hamilton with higher yield, extremely small device (16 kg). |
| Santa Fe | October 30, 1958 03:00:00.1 | PST (–8 hrs) | NTS Area B7b ~ 37°05′12″N 116°01′28″W / 37.0866°N 116.0245°W | 1,282 m (4,206 ft) + 460 m (1,510 ft) | balloon, weapons development | XW-54 Gnat | 1.3 kt | Venting detected, 220 kCi (8,100 TBq) | [1][6][8][10] | Similar to devices fired in many preceding shots, yield below predictions. |
| Ganymede | October 30, 1958 11:00:?? | PST (–8 hrs) | NTS Area S9g 37°07′23″N 116°02′06″W / 37.123°N 116.035°W | 1,294 m (4,245 ft) + 0 | dry surface, safety experiment | W-45 | no yield | [1][6][7][8][11] | 1-point test of W-45/Swan variant, successful. | |
| Blanca | October 30, 1958 15:00:00.15 | PST (–8 hrs) | NTS Area U12e.05 37°11′09″N 116°12′10″W / 37.18589°N 116.20289°W | 2,168 m (7,113 ft)–254.51 m (835.0 ft) | tunnel, weapons development | XW-47 primary Canary | 22 kt | Venting detected, 510 Ci (19,000 GBq) | [1][6][7][8][9][10] | Test of alternate W-47 primary in TN mockup, successful, similar to Evans, shot vented to atmosphere through the side of the mesa. |
| Titania | October 30, 1958 20:34:00.2 | PST (–8 hrs) | NTS Area 8c 37°10′38″N 116°04′12″W / 37.1773°N 116.0699°W | 1,343 m (4,406 ft) + 10 m (33 ft) | tower, safety experiment | XW-47 primary Canary | 200 kg | [1][6][7][8] | 1-point test of original XW-47 primary, declared safe despite yield, similar to HT-I Hickory and HT-II Neptune. | |
| Adams (canceled) | October 31, 1958 | PST (–8 hrs) | NTS ~ 37°02′38″N 116°04′05″W / 37.044°N 116.068°W | 1,220 m (4,000 ft) + ??? | Balloon, weapons development | unknown yield | Test planned for Hardtack II, but held up by atmospherics that would have shattered windows in Las Vegas, and could not be completed in time before start of moratorium negotiations. |
References
External links
- The short film Operation HARDTACK Military Effects Studies Part I: Basic Effects Structures and Materiel (1958) is available for free viewing and download at the Internet Archive.
- The short film Operation HARDTACK Military Effects Studies Part II: Underwater Tests (1958) is available for free viewing and download at the Internet Archive.
- The short film Operation HARDTACK Military Effects Studies Part III: High Altitude Tests (1958) is available for free viewing and download at the Internet Archive.
- The short film Operation HARDTACK Military Effects Studies: Part IV - Sub-kiloton effects is available for free viewing and download at the Internet Archive.
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