FF3/7.3/32:mf J15~9 grey. 4 MAR 5MAR 0800 20° 6. wu 6 MAR 0800 7 12 7 MAR @MAR 0800 0800 5 ho: 10 8 These three ships are chosen as examples because the BAIROKO and PHILIP were the most heavily contaminated in the beginning, and the GYPSY (ARSD 1) was the most heavily contaminated one week later, It is believed that contamination clung .to the GYPSY longer than to other ships because of the condition of her topside, which was quite rusty due to her recent heavy employment without adequate opportunity for unkeep, Another factor tending to increase radioactive intensity. on the GYPSY was her recent employment to recover contaminated chains and mooring gear from the bottom of the lagoon, 5. Three (3) barges, ten (10) LCUs and ten (10) LCMs were anchored or moored in the southeast portion of the lagoon off ENYU Island (about 20 miles from ground. zero) prior to the detonation, as it was not considered practicable nor safe 'tq’. take them to sea -in the prevailing weather.. (BELLE GROVE (LSD 2) had eighteen « (18) -other LCMs and one (1) AVRin her well at shot, time), These craft left in the lagoon suffered no damage from blast, heat or wave action, but all were >. heavily contaminated by radioactive fallout to such exterit that about twelve (12). hours after shot time, they had a radioactive intensity averaging several roentgens per hour,’ Subsequently, all were washed down with ‘hoses from, other vessels..(thé~ .high pressure hoses of GYPSY proved particularly effective as GPSY was maneuvered successively in the close vicinity of these craft), followed by a thorough: |"| -decontamination by additional hosings and scrubbings by decontamination personnel who, by this time, were able to board the craft, All these masures were: sufficiently effective that average radioactive intensity of these craft is now only about two (2) mr per hour (gamma only)... 6. By three (3) days after the shot, all the water in BIKINI Lagoon had becoms slightly contaminated with radioactive mterial, Contamination was of the order of one microcurie per liter. Fortunately, drinking wter produced by ships’ - evaporators from lagoon water has show no activity.. The salt water systems, such as evaporators, .condensers, fire mains, etc., on most ships became gradually contaminated, and at one tim: it was feared this might become a major problem. However, ten (10) days after detonation the radioactive intensity of the salt water system ceased to increase, and at the present time this intensity is decreasing. The highest. intensity of this kind detected was 30 milliroentgens per hour (gamma only) on the exterior of an auxiliary condenser of USS CURTISS. The average