SECTION 2 SHIP OPERATIONS AND RADIATION ENVIRONMENTS This section describes the movements of the TG 7.3 ships at the Pacific Proving Grounds during Operation CASTLE and correlates these movements with the radiation environment following the six detonations in the test series. Ship movements are reconstructed primarily from data contained in the deck logs of the sixteen ships of interest (References 8 and 9). The shipboard radiation environments resulting from radioactive fallout are reconstructed based on available radiolégical survey data. In the absence of ship-specific radiological data, topside radiation environments are inferred from those of other nearby ships or island data from Enewetak, Kwajalein, and Bikini Atolls, as appropriate. In addition, as ships operated in the contaminated waters of Bikini Lagoon, their hulls and interior salt water systems became radiologi- cally contaminated exposing personne! below to varying degrees of radiation. The radiation environments below are derived from a previously-developed ship contamination model. 2.1 SHIP OPERATIONS Exclusive of the landing craft and small boats belonging to the boat pool, TG 7.3 had 31 surface craft in the Pacific Proving Grounds for Operation CASTLE. reconstruction focuses on sixteen of the ships: This APACHE (ATF-67), BAIROKO (CVE- 115), BELLE GROVE (LSD-2), CURTISS (AV-4), EPPERSON (DDE-719), ESTES (AGC12), FRED C. AINSWORTH (TAP-181), GYPSY (ARSD-1), LST-551, LST-762, LST825*, LST-975*, NICHOLAS (DDE-449), PHILIP (DDE-498), RENSHAW (DDE-499), and SIOUX (ATP-75). . The AINSWORTH served as living quarters’ afloat for the bulk of the support personnel. The two tugs, APACHE and SIOUX, placed and retrieved floating instrumentation. The GYPSY, salvage lifting vessel, performed salvage operations in the lagoon and assisted in decontaminating the harbor craft and small! boats that were * Not assigned to TG 7.3. 16