in raising the SIO probe eboard the YAG-39 prolonged thisevent. The Horizon departed and the YAG~39 continued to keep station on the drogue. After considerable difficulty in lowering and raising the SIO probe, a technicue of stopping the ship during this measurement was adopted but by 1&00 the gear was no longer operable and after taking a final set of water samples this ship departed for Eniwetok at 2054. Throughout the time from the beginning of fallout to the return to Eniwetok, the ship was closed and personnel remained in shielded spaces except as necessary to acccmplish ship end project work. Due to the numerous events, the radiological situetion and washdown operation ere best presented in a cnrcnological table. O7L7 0753 0828 0853 1100 1245 1530 1550 1635 1703 1941 2050 2125 2135 2158 2240 2325 2345 Fallout arrival Washdown on Washdown off. Men to TV camera at mast head and to release jammed limit switch on SIO rrote hoist. VWashdown on Peak activity on fore deck of 27 rf/hr Estimated time of cessation of principal fallout. The Cepteain observed from the bridge that washdown nozzles on the top of house (flying tridge) were probebly closed. Turned washdown off. Took air sample--well above tolerance-noted much loose material on deck. Valves controlling nozzles on top of house opened, Washdown on waskdown off. Drogue leunched and took water samples. Washdown on Washdown off. Took air sample--searched for and found drorue. Washdown on Washdown off to sicht drogue Washdown on Washdown off--took water samples. Washdown on Washdown off to sight drogue. Washdown on T+1 (22 July 1956) 0020 Washdown off to sight dropue 0210 Washdown off. Took water samples, opened engineroom vents and hatch. At meal time only, starting with breakfest, the two aft passage way doors on the main deck were opened to provide ventiletion and reduce the high ambient temperatures in the galley, After : : ; ‘ i opening the ensineroom ventilation, shoe covers end d ¢ gloves were recuired in the engine room. The engineroom door wes kept clos ds 0026 Notes: Cr PIEN 5A ~PIED/ OGE BNL RO > Washdown on -~19-

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