Mine Throw was a series of tests conducted by the Defense Nuclear Agency using conventional charges to simulate the blast effects of nuclear weapons. This series is poorly attested. It appears that only one of three planned tests was actually conducted. The associated Pre-MINE THROW tests were initiated in advance of the first Mine Throw event, and continued subsequent to the cancellation of the second and third events.
One fairly authoritative source reports that the Mine Throw event took place on 29 April 1971. A large scale test, MINE THROW, was planned in which the crater and ground motions generated by JOHNNY BOY, a 500 ton TNT equivalent shallow buried nuclear burst in alluvium, was to be duplicated with ANFO. Johnny Boy, detonated on 11 July 1962, had a yield of 500 plus or minus 20 tons. It was buried to a depth of 2 feet in alluvium.
If normal density ANFO were to be used on MINE THROW, the initial excavation size would be so small that not enough ANFO could be used as the explosive liner to generate the required impulse. Hence, PI embarked on a program to develop low density ANFO, one with a detonation pressure of about 55 kilobars. By adding low density polystyrene beads to the normal ANFO, they achieved mixtures that exhibited stable detonations over the density range from 0.5 to 0.9 g/cm3.
A mixture with a density of 0.75 g/cm3 and a calculated detonation pressure of 56 kilobars was selected for the MINE THROW II event, which was not conducted.
The Pacific Cratering Experiments (PACE) were conducted on Enewetak Atoll. PACE involved three integrated and concurrent test programs. "Micro Atoll" consisted of fifteen 1,000 pound detonations of high explosives (twelve of which took place before the issuance of a temporary restraining order on 22 September 1972), three 5 ton detonations and four 20 ton detonations. "Mine Throw II" was a planned 220 ton detonation. "Coral Sands" was a planned 500 ton detonation.
Enewetak is a Pacific atoll administered by the United States under a "Trust Agreement" with the United Nations pertaining to the Trust Territory of the Pacific Islands, the former Japanese Mandated Islands. Enewetak, also commonly spelled Eniwetok, is the westernmost atoll of the Western (Ralik) Chain of the Marshall Islands and is located north of the equator in the west-central part of the Pacific Ocean between 11°20' and 11°46' north latitudes, and 162°02' and 162°24' east longitudes. The atoll consists of a chain of forty two islands surrounding an oval lagoon 25 miles long by 20 miles wide. The total land area of the islands is 2.26 square statute miles.
In 1947 the inhabitants of Enewetak were moved to Ujelang Atoll by the United States so that Enewetak could be used as a nuclear test site. From that time until the voluntary nuclear test moratorium went into effect in 1958 more than thirty nuclear devices were detonated on the islets and reef ledge of the atoll including, in 1952, the world's first explosion of a hydrogen bomb.
In September 1971 the Air Force Pacific Cratering Experiments (PACE) project begun on Enewetak. More than 220 tons of explosives brought to Enewetak for series of tests, aimed at simulating nuclear bomb blasts. Six tons actually detonated; 190 holes drilled into reefs and land for explosives; and 86 trenches (seven feet deep, 3 feet wide and 6 feet long) dug in different parts of the atoll.
A Draft Environmental Statement was prepared for the PACE project and filed with the Council on Environmental Quality on 18 April 1972 ("April 18th DES"). The Government acknowledged that the Draft EIS was inadequate under NEPA, and it was agreed that a new Statement would be prepared. It was stipulated that a preliminary injunction would issue pending final determination of this action after trial on the merits; reserving, however, the question whether the scope of the injunction should preclude the defendants from continuing core drilling and seismic studies on the atoll.
According to the April 18th DES, PACE was one part of a larger program designed to provide new data on the vulnerability of certain elements of America's strategic defenses to nuclear attack. Its specific purpose was to test the "cratering" effect of nuclear blasts by simulating such blasts with high explosives. Testimony at the hearing on the Order to Show Cause indicated that these detonations would range upward in size to 500 tons of high explosive. In addition, large areas on the islands woud be cleared of "overburden" (vegetation and topsoil) preparatory to the detonations.
In September 1972 Conard medical team discovered two more Marshallese with thyroid abnormalities, one from Ailingnae and the other from Rongelap. To date, 18 out of 19 Rongelap people who were under 10 years old when exposed to radiation from "Bravo" in 1954, have had thyroid abnormalities.
Enewetakese filed suit in federal court in Hawaii to stop Air Force PACE project. Temporary injunction granted. In January 1973, federal judge orders program halted. On 19 January 1973, the suit The PEOPLE OF ENEWETAK et al., Plaintiffs, v. Melvin R. LAIRD, Secretary of Defense, et al., Defendants, Civ. No. 72-3649 was decided by the United States District Court, Distric of Hawai'i. This suit was brought by the hereditary and elected leaders of the people of Enewetak Atoll seeking a preliminary injunction against defendants Melvin R. Laird, Robert C. Seamens, Philip N. Whittaker, Noel Gayler and Caroll H. Dunn. Defendants are respectively, Secretary of Defense, Secretary of the Air Force, Assistant Secretary of the Air Force, Commander in Chief of the United States Military Forces in the Pacific Ocean area and Director of the Defense Nuclear Agency. The complaint alleged that defendants have not complied with the provisions of the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C. § 4321 et seq. (Supp.1972), and other laws of the United States, [FN2] in the manner in which they initiated and conducted the Pacific Cratering Experiments (PACE) on Enewetak Atoll. The Judge found in favor of the plaintiffs.
The Pentagon in June 1973 called off the PACE tests in face of court action by Enewetakese.
The Mine Throw III site was developed at Split Ridge, Nevada Test Site, Nevada, but it the test was not conducted.
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