TOP GUIDELINES OF UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958)

With test moratoriums around the horizon, American weapons labs rushed out quite a few new styles. A hard deadline for testing was established at midnight (0000 hrs), 31 Oct 1958, as negotiations had been established to get started on that working day, plus the routine demonstrates it, with 29 tests executed in October, 4 of these on the final day.