Order number page 16 940406-16 5953-13 -001-001 set 5 wi th 341 of 341 items massive destruction had been developed. Japan’s surrender, the military, Soon after led by the Navy, began to advocate a series of atomic bomb detonations to test their effect on naval vessels and other military equipment and to determine other results of such a detonation. In the summer of 1946, as Crossroads, in an operation known two atomic bomb tests took place, one an airdrop and one an underwater detonation. The operation was conducted far outside the continental US in Bikini Lagoon in the Marshall Islands. Involved were 42,000 people, over 200 vessels, and more than 150 airplanes. The tests could not have taken place without the participation of staff from the Los Alamos Laboratory. The Laboratory supplied the two nuclear weapons, detonated the underwater bomb, provided radiochemical yield data and other diagnostic data, assisted in other technical operations such as timing, and provided general technical advice. The operational organization of Crossroads set many precedents for conducting future 801. KEYWORD (S) tests. Crossroads was an important step in preparing the Laboratory for the test series that were to follow. (U) CROSSROADS/historical aspects ;CROSSROADS; ATOMIC WEAPON TESTS; TEST OBSERVERS ; LOGISTICS; PLANNING; SAFETY; UNDERWATER BURSTS; ATMOSPHERIC BURSTS; DIAGNOSTIC EXPERIMENTS; ABLE BURST; BAKER BURST Item 28 150. REPORT NUMBER 110. PRIMARY TITLE (M) 710. CORPORATE SOURCE 371. PUB. DATE (YYMMDD ) 34. CLASSIF. LEVEL T EXT 36. CLASSIF. 950. ABSTRACT 801. NVO--102-2 NVOO program and project schedule USDOE Nevada Operations Office, Las Vegas 720131 Secret CATAGORY TEXTRestricted Data KEYWORD (S) 9003213 ATOMIC WEAPON TESTS/research programs ;GROMMET; CANNIKIN BURST; BARBIZON;MINUTE GUN;MILD WIND; HUSSAR