Project 58/58A
| Project 58/58A | |
|---|---|
Coulomb-C, 0.5 kilotons. | |
| Information | |
| Country | United States |
| Test site |
|
| Period | 1957–1958 |
| Number of tests | 4 |
| Test type | dry surface, underground shaft, tunnel |
| Max. yield | 500 tonnes of TNT (2,100 GJ) |
| Test series chronology | |
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 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.
| Name | Date time (UT) | Local time zone | Location | Elevation + height | Delivery Purpose |
Device | Yield | Fallout | References | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| Pascal-C | December 6, 1957 20:15:00.0 | PST (–8 hrs) |
NTS Area U3e 37°03′00″N 116°01′54″W / 37.04992°N 116.03159°W | 1,202 m (3,944 ft)–80 m (260 ft) | underground shaft, safety experiment |
XW-42 ? | 10 t | One point safety test, partially successful (?). | ||
| Coulomb-C | December 9, 1957 20:00:?? | PST (–8 hrs) |
NTS Area S3i 37°02′39″N 116°01′50″W / 37.0443°N 116.0305°W | 1,225 m (4,019 ft) + 0 | dry surface, safety experiment |
Moccasin | 500 t | I-131 venting detected, 69 kCi (2,600 TBq) | One point safety test, upper bound overtest. Similar to the Moccasin device fired in Hardtack II Hidalgo. Failure, 500 ton explosion. | |
| Venus | February 22, 1958 01:00:00 | PST (–8 hrs) |
NTS Area U12d.01 37°11′41″N 116°12′02″W / 37.19475°N 116.20068°W | 2,104 m (6,903 ft)–30.48 m (100.0 ft) | tunnel, safety experiment |
XW-47 primary ? | 500 kg | One point safety test, partially successful (?). Similar to Hardtack II Oberon and Sanford devices. | ||
| Uranus | March 14, 1958 22:00:00 | PST (–8 hrs) |
NTS Area U12c.01 37°11′36″N 116°12′01″W / 37.193397°N 116.20014°W | 2,068 m (6,785 ft)–34.75 m (114.0 ft) | tunnel, safety experiment |
XW-48 | 500 kg | One point safety test, partially successful (?). Similar to devices fired in Hardtack II Mars, Tamalpais, and Ceres. |