UNSENE vem ‘a - -_— : Bost TY . FeO ee |: wah Sam tO ‘ At H~plus 3 hours two monitors boarled the Tank LOM as it came by the BAIROKO and proceeded to the zero island to await Dr. Borman who was to fly to the island by helicopter after supervising the removal of filters from the drone plincs at Enivetok. Or. Bowran arrived at 1050, and flass were pliced at the center of the causeway marking the Limit of safety for the tank controllins helicopter. The helicopter in which the tank operator, was ridin: was forced dam by engine trouble on another island, and caused some delay before he could be flown in for the operation, At 1030 the operation was ready. The tank that had been stationed in the revetment during the test was driven manually to the causeway, and fron thence proceeded under remote control operation to the crater formed by the test weapon. The tank soon became bogged down, and efforts to zet it started asain were unavailing. The reserve tank that had been brought up in the LCi was then sent in and succesfully obtained a soil sample fron the desired point, returning to the uncontaminated end of the island. This soil sample was divided, a small portion being sent to the laboratories on the USS BAIROKO, and the remainder being taken to Eniwetol: by one of the monitors. This latter sample reached Eniwetok by 1510 and ras dispatched by air to laboratories in the United States. During this entire operation a standby helicopter with a monitor took up a position near the tank controllins helicopter, in order to insure that the latter would not be overexposed to radioactivity. iihen this plane landed to investigate the trouble with the tank, the monitor in the other helicopter checked most of the island at an altitude of 500 feet, except that portion in the vicinity of the zero point. The evaporators on the BAIRCKO and on the LT MCKINLEY were checked for radioactivity and found satisfactory, YOKE Plus Two Day The northeast perineter survey of the islands left the BAIROKO at 0930 in two dukws. Extensive evidence of fall-out was found on all the islands of this section. A detailed survey was impracticable within the restrictions of a routine mission, and readings had to be taken while moving rapidly along the beaches in the dukws, Only half of the islands planned for survey could be covered before tolerance doses had been received by all personnel. Some evidence of water contamination was observed, and all results were reported in detail to Radops where a complete fall-out report was prepared, At about 1000 hours the background on the tlisht deck and hanger deck of the USS BAIROKO beran to noticeably increase, and it shortly became evident that appreciable fall-out was occuring on the ship. About the same time, it was reported that fall-out had occured on Kyajalein,, and steps were taken to fly water samples to the laboratories on the BAIROKO for study. The maximum reading recorded on the BAIROKO was 1.7 mr/hr. Hourly samples of filter papers froin the dust collectors were taken - Tw