where available, because experience at IVY indicated that blueboxes were not always reliable. Hewever, toward the end of this operation. bluebox signals were used where feasible, because of the satisfactory performance of the modified blueboxes. At the raft stations, the IFC timing signal came from the Project 2.5a nondirectional, photoelectric, trigger mechanism. 204 MOUNTINGS At the Bikini land stations, the IFC and its batteries were usually mounted in concrete foundations (Figs 2.9). At the Bikini lagoon stations, the equipment was mounted on wooden platforms bolted to 60=-man Navy life floats (Fig. 2.10). These floats were moored to floats identical to those used by Project 2.5b. The Project 2.5a floats in turn were tied to mooring buoys furnished by Holmes and Narver, Ince At the Eniwetok lend stations, the IFC and the wooden battery boxes were dug into the ground flush with the surface (Fig. Zell). 205 PROJECT PARTICIPATION This project participated in Shots 1, 2, 3, and 4 at Bikini Atoll and in Shot 6 at Eniwetok Atoll. ded to participate in Shot 5. It had been originally inten~ However, water wave damage to the stations from Shot 4 made participation in Shot 5 impractical. Generally, IFC's were placed in groups of two at Bikini loca~ tions, and singly at the Bikini raft and Eniwetok stations. Where two IFC's were on an island or raft station, one was set to sample for 12 hr at 30-min intervals and the other was set to sample for either 24 min at l-min intervals or for 2 hr at 5=min intervals. The l-min samples were collected for Project 2.6b to deterrtine the degree which the base surges was contributing to the residual contamination pattern. The 5emin interval instruments documented the early fallout and the 30-min interval instruments documented the fallout for the mximum length of time possible with this instrument. Where one IFC was located at a station or raft, it was set to sample at 30=-min intervals for 12 hr. : The station locations and timing intervals are listed in Tables 2ely 2e2, and 2.3 and shown in Figse 2.12 and 2.16. 206 OPERATIONS Operations were extremely difficult following Shot 1. Immedi- ately following this event, the project's main base of operations at Tare was razed by fire and most spare parts, auxiliary equipment, and operational supplies were lost. The long delay before Shots 2, 4, and 6 imposed additional difficulties because the batteries readily discharged in the hot weather,requiring frequent trips to the stations with battery replacements. Heavy seas in the Bikini Lagoon caused the cancellation of the Bikini raft station program. The rafts broke away from their moor= ings with distressing frequency. Locating and mooring the rafts in 19