OPERATION CASTLE - DAVE: TIME: PPG Time 1 Mar 1954 O6h5 TOTAL YIELD: ~ Bravo GM? Sponsor: 28 Feb 195) 1845 SITE: 15 Mt FIREBALL DATA: LASL PPG - Bikini - on reef between Burner and Charlie Ve hat 165° 36" Site elevation: Timetolst minimum: 313 to 250 msec Time to 2nd maximum: 3.54 to 3.95 sec Radius at 2nd maximum 9,512 ft TYPE OF BURST AND PIACEMENT: Surface burst from platform on HEIGHT OF BURST: eo" ON is Sca level 7 ft CLOUD TOV HEIGHT: 114,000 ft CLOUD BOTTOM WEIGH: 55,300 ft CRATER DITA: Coral soil a7" Diameter: Depth: Lip: 6,000 {t 240 ft. Apparently washed away REMARKS: The on-site fallout pattern was constructed from survey measurements on Bikini Atoll, and from samples obtained with the total collectors and gummed paper collectors. The free-floating sea stations were not in the correct location to receive primary fallout. The data were cxlrapolated to Htl hour by the composite gamma-ionization=decay curve obtained from samples measured in the laboratory. This is the only megateon shot where some downwind land areas were unexpectedly contaminated; thus, partial documentation of fallout effects was possible, However, the major portion of the fallout occurred over the open oces;: and was not documented. Eccause this chot is one of those used as the Lasis of fallout predicticr fcr megaton yield weapons, three off-site fallout patterns arc presented. The mosu widely known pattern is shown in Figure 40. It was construcced immediately after the event from the preliminary data available at Fus, #J*SWe. The second pattern was constructed by NRDL by establishing an coxperimental model; the field data plus a thorough analysis of the wind structure existing at and after shot time was used. The third pattcrn was consiructed by RAND Corp., by supplementing, field observations with mode] calevlationc. 63