NEW STEP BY STEP MAP FOR UNDERWATER NUCLEAR TEST 'UMBRELLA' (1958)

With test moratoriums around the horizon, American weapons labs rushed out quite a few new types. A hard deadline for testing was set at midnight (0000 hrs), 31 Oct 1958, as negotiations ended up set to begin that working day, and the agenda exhibits it, with 29 tests executed in October, four of these on the final day. One other test was cancelled