Operation Hardtack - Military Effects Studies Part 2

Operation Hardtack I consisted of 35 nuclear tests conducted at the Pacific Proving Ground between April 28 and August 18, 1958. These tests included balloon, surface, barge, underwater, and rocket-borne high-altitude tests. The first test, YUCCA, was a nuclear device attached to a helium balloon launched from the USS Boxer near Enewetak Atoll. Hardtack I consisted of three portions; the first was the development of nuclear weapons. This was a continuation of the type of testing conducted at Enewetak and Bikini during the early and mid-1950s. In these tests, the weapons development laboratories, Los Alamos Scientific Laboratory and the University of California Radiation Laboratory, detonated their experimental devices, while the Department of Defense (DoD) provided support and conducted experiments that did not interfere with Atomic Energy Commission activities. The second portion, sponsored by DoD, consisted of the underwater tests WAHOO and UMBRELLA. WAHOO was detonated in the open ocean and UMBRELLA in the lagoon at Enewetak. The purpose of these tests was to improve the understanding of the effects of underwater explosions on Navy ships and material. These were continuations of earlier underwater testing that included BAKER in Crossroads at Bikini in 1946 and WIGWAM off the U.S. West Coast in 1955. The DoD also sponsored the third portion, addressing the military problems of air-borne nuclear weapon defense. Three high-altitude tests featured rocket-borne TEAK and ORANGE at Johnston Island and balloon-hoisted YUCCA between Enewetak and Bikini. Two major aspects of Hardtack Is experimental program were the development of the weapons themselves and the measurement of the explosive and radiation effects. Also, since the development of a nuclear armed fleet ballistic missile was on a fast track, a portion of Hardtack I was devoted to testing the warhead for the Polaris missile. The tests comprising the 1958 Operation Hardtack I were as follows: YUCCA, April 28, Pacific (between Enewetak and Bikini), balloon, weapons effects, 1.7 kilotons (kt) CACTUS, May 5, Enewetak, surface, weapons related, 18 kt FIR, May 11, near Bikini, barge, weapons related, 1.36 megatons (Mt) BUTTERNUT, May 11, near Enewetak, barge, weapons related, 81 kt KOA, May 12, Enewetak, surface, weapons related, l.37 Mt WAHOO, May 16, near Enewetak, underwater, weapons effects, 9 kt HOLLY, May 20, near Enewetak, barge, weapons related, 5.9 kt NUTMEG, May 21, near Bikini, barge, weapons related, 25.1 kt YELLOWWOOD, May 26, near Enewetak, barge, weapons related, 330 kt MAGNOLIA, May 26, near Enewetak, barge, weapons related, 57 kt TOBACCO, May 30, near Enewetak, barge, weapons related, 11.6 kt SYCAMORE, May 31, near Bikini, barge, weapons related, 92 kt ROSE, June 2, near Enewetak, barge, weapons related, 15 kt UMBRELLA, June 8, near Enewetak, underwater, weapons effects, 8 kt MAPLE, June 10, near Bikini, barge, weapons related, 213 kt ASPEN, June 14, near Bikini, barge, weapons related, 319 kt WALNUT, June 14, near Enewetak, barge, weapons related, 1.45 Mt LINDEN, June 18, near Enewetak, barge, weapons related, 11 kt REDWOOD, June 27, near Bikini, barge, weapons related, 412 kt ELDER, June 27, near Enewetak, barge, weapons related, 880 kt OAK, June 28, near Enewetak, barge, weapons related, 8.9 Mt HICKORY, June 29, near Bikini, barge, weapons related, 14 kt SEQUOIA, July 1, near Enewetak, barge, weapons related, 5.2 kt CEDAR, July 2, near Bikini, barge, weapons related, 220 kt DOGWOOD, July 5, near Enewetak, barge, weapons related, 397 kt POPLAR, July 12, near Bikini, barge, weapons related, 9.3 Mt SCAEVOLA, July 14, near Enewetak, barge, safety experiment, zero yield PISONIA, July 17, near Enewetak, barge, weapons related, 255 kt JUNIPER, July 22, near Bikini, barge, weapons related, 65 kt OLIVE, July 22, near Enewetak, barge, weapons related, 202 kt PINE, July 26, near Enewetak, barge, weapons related, 2 Mt TEAK, August 1, off Johnston Island area, rocket, weapons effects, 3.8 Mt QUINCE, August 6, Enewetak, surface, weapons related, zero yield ORANGE, August 12, off Johnston Island area, rocket, weapons effects, 3.8 Mt FIG, August 18, Enewetak, surface, weapons related, 20 tons