Operation Hardtack I

Operation Hardtack I
Hardtack I-Teak, 3.88 megatons.
Information
CountryUnited 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
Period1958
Number of tests35
Test type
  • Air drop
  • Balloon
  • Barge
  • Dry surface
  • High-altitude rocket
    30–80 km (98,000–262,000 ft)
  • Underwater detonation
Max. yield9.3 megatons of TNT (39 PJ)
Test series chronology
Map all coordinates in "Operation Hardtack I" using OpenStreetMap

Download coordinates as:

Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds.[1][2]: 212  At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of prior nuclear explosions in the Pacific Ocean.[3]: 1  These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.[2]: 212–214 

Operation Hardtack I was directed by Joint Task Force 7 (JTF 7). JTF-7 was a collaboration between the military and many civilians, but was structured like a military organization. Its 19,100 personnel were composed of members of the US military, federal civilian employees, as well as workers affiliated with the Department of Defense (DOD) and the Atomic Energy Commission (AEC).[3]: 1 

There were three main research directions. The first was the development of new types of nuclear weapons. This was undertaken by detonating experimental devices created by the AEC's Los Alamos Scientific Laboratory and the University of California Radiation Laboratory (UCRL). The DOD performed experiments and tests on these detonations that did not hamper the AEC's research. The second research direction was to examine how underwater explosions affected materiel, especially Navy ships, and was performed by the DOD. The Wahoo test was conducted in the open ocean, whereas Umbrella was in a lagoon.[3]: 1  The final avenue of study was to analyze high-altitude nuclear tests to refine the detection of high-altitude nuclear tests and investigate defensive practices for combatting ballistic missiles. This research direction was composed of three individual tests and were the first high-altitude tests. The individual tests in the series were Orange, Teak, and Yucca. Orange and Teak were known collectively as Operation Newsreel and were rocket boosted. Yucca reached its altitude using balloons.[1][2]: 187 [3]: 3 

Aerial shot of the explosion during Hardtack I Poplar. Martin RB-57D in the foreground.
  1. ^ a b Cite error: The named reference LT_1 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference CW_1 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference CW_2 was invoked but never defined (see the help page).