Enewetak Atoll Nuclear Tests: "The Navy's Part in Operation Sandstone" 1948 AEC-USN (Patreon)

more at http://quickfound.net/

'Operation Sandstone was a series of nuclear weapon tests in 1948. It was the third series of American tests, following Trinity in 1945 and Crossroads in 1946, and preceding Ranger. Like the Crossroads tests, the Sandstone tests were carried out at the Pacific Proving Grounds, although at Enewetak Atoll rather than Bikini Atoll...'

Originally a public domain film from the National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/Operation_Sandstone

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

Operation Sandstone was a series of nuclear weapon tests in 1948. It was the third series of American tests, following Trinity in 1945 and Crossroads in 1946, and preceding Ranger. Like the Crossroads tests, the Sandstone tests were carried out at the Pacific Proving Grounds, although at Enewetak Atoll rather than Bikini Atoll. They differed from Crossroads in that they were conducted by the Atomic Energy Commission, with the armed forces having only a supporting role. The purpose of the Sandstone tests was also different: they were primarily tests of new bomb designs rather than of the effects of nuclear weapons. Three tests were carried out in April and May 1948 by Joint Task Force 7, with a work force of 10,366 personnel, of whom 9,890 were military.

The successful testing of the new cores in the Operation Sandstone tests rendered every component of the old weapons obsolete. Even before the third test had been carried out, production of the old cores was halted, and all effort concentrated on the new Mark 4 nuclear bomb, which would become the first mass-produced nuclear weapon. More efficient use of fissionable material as a result of Operation Sandstone would increase the U.S. nuclear stockpile from 56 bombs in June 1948 to 169 in June 1949...

As in Operation Crossroads, each detonation was given its own code name, taken from the Joint Army/Navy Phonetic Alphabet. All used modified Mark III assemblies, and were detonated from 200-foot (61 m) towers...

The X-Ray nuclear device used a levitated composite core. It was detonated on Enjebi just before sunrise at 06:17 on April 15, 1948, with a yield of 37 kilotons. The efficiency of utilization of the plutonium was about 35%; that of the uranium-235 was 25% or more. This was somewhat higher than Los Alamos' prediction...

The Yoke nuclear device used a levitated all-uranium-235 core. It was detonated on Aomon just before sunrise on May 1, 1948 at 06:09, a day late due to unfavorable winds. The observers saw a similar flash and felt the same heat as the X-Ray blast, but the 6-nautical-mile (11 km; 6.9 mi) wide condensation cloud was larger, and the sound of the explosion more forceful. One observer likened it to the sound of "a paper bag which is forcefully burst in a small room". They were correct: its yield of 49 kilotons made it the largest nuclear detonation up to that time,[39] but it was considered inefficient and wasteful of the fissile material.

Zebra, the third test, and the last of the Sandstone series, was detonated on Runit just before sunrise at 06:04 on May 15, 1948... this time the base of the condensation cloud was at 2,000 feet (610 m), which gave the observers an unobstructed view of the fireball, which therefore appeared to be brighter and last longer than the other two. Looks were deceiving: its levitated uranium-235 core produced a yield of 18 kilotons...

Outcome

The successful testing of the new cores in the Sandstone tests had a profound effect. Practically every component of the old weapons was rendered obsolete. Even before the third test had been carried out, Bradbury had halted production of the old cores, and ordered that all effort was to be concentrated on the Mark 4 nuclear bomb, which would become the first mass-produced nuclear weapon. The more efficient use of fissionable material would increase the nuclear stockpile from 56 bombs in June 1948 to 169 in June 1949. The Mark III bombs were withdrawn from service in 1950. At the same time, new production plants were coming online and the Wigner effect problem had been solved. By May 1951, plutonium production was twelve times that of 1947, while uranium-235 production had increased eight-fold. The Chief of the Armed Forces Special Weapons Project, Major General Kenneth D. Nichols, saw clearly that the era of scarcity was over. He now "recommended that we should be thinking in terms of thousands of weapons rather than hundreds."