DETAILED NOTES ON UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958)

With test moratoriums within the horizon, American weapons labs rushed out several new styles. A tough deadline for testing was set at midnight (0000 hrs), 31 October 1958, as negotiations ended up set to get started on that working day, plus the plan displays it, with 29 tests executed in October, four of these on the last working day. Just one ot