TOP UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958) SECRETS

With test moratoriums over the horizon, American weapons labs rushed out a lot of new layouts. A hard deadline for testing was set at midnight (0000 hrs), 31 October 1958, as negotiations were set to begin that day, plus the agenda demonstrates it, with 29 tests executed in Oct, four of them on the last day. A single other test was cancelled mainly