Operation Project 58/58A was a series of 4 nuclear tests conducted by the United States in 1957–1958 at the Nevada Test Site. These tests followed the ''

Operation Plumbbob Operation Plumbbob was a series of nuclear tests that were conducted between May 28 and October 7, 1957, at the Nevada Test Site, following ''Project 57'', and preceding '' Project 58/58A''. Background The operation consisted of 29 explosions ...

'' series and preceded the '' Operation Hardtack I'' series. All the tests in ''Project 58'' were one-point safety tests. They were intended to freeze device designs prior to full-scale tests at '' Operation Hardtack I''. No significant yield was expected from either, but the second, ''Coulomb-C'', a surface test conducted on December 9, produced an unanticipated yield of 500 tons. Shortly after detonation, fallout readings of fifty roentgens per hour were recorded on the Mercury Highway, and, as the cloud moved toward the southwest, personnel at Jackass Flats involved in construction for future nuclear rocket testing were forced to take cover. Eventually, the cloud reached the Los Angeles area where readings caused public concern.U.S. Department of Energy, ''Battlefield of the Cold War, The Nevada Test Site, Volume 1, Atmospheric Nuclear Weapons Testing, 1951-1963''
DOE/MA-0003

References

{{DEFAULTSORT:Project 58 58A 1957 in Nevada 1958 in Nevada Explosions in 1957 Explosions in 1958 1957 in military history 1958 in military history Nevada Test Site nuclear explosive tests