pickup vessels. The project had personnel aboard the USS Munsee, the USS Mactobi (ATF-105,, and the Task Group 7.4 crash boat (AVR), all of which were assigned to FFP pickup. Although many FFP’s were seen by both aerial and surface units, only 10 out of a total of 65 were recovered, an effective recovery of about 15 percent. The principal difficulty lay in a failure of communication between Rad-Safe contro! and the task force elements attempting to retrieve FFP’s. Consequently, ships that were to have recovered FFP’s would not enter the presumed radex area where most of the FFP’s happened to be concentrated. FFP recovery was terminated at H+4 hours, since Task Group 7.4 required all spotting helicopters to return to Eniwetok Isiand by 1800. Rad-Safe control permitted D-day entry on DD-593 only; therefore, early recovery was effected only on this ship. This recovery was performed at H+ 4a, hours, and these samples, together with aliquots of all sample solutions usec in early chemistry were placed aboard the H+8 hour flyaway (Appendix F). Three coracles were also recovered on D-day by the USS Munsee. One coracle was overturned, and 10 deep moors were parted by the detonatior. (Section 2.3.2). All moors broke near the bottom; therefore, the coracle drift rates were substantially reduced, which greatly simplified recovery on the following day. On D+1 day a number of Task Group 7.3 ships recovered all remaining coracles and returned them to the BWA on Parry Island for further processing. The USS Bolster (ARS-38) recovered two coracles; the USS Grasp (ARS-24), seven; the USS Mactobi, two; and the USS Munsee, six. Although these additional vessels were able to perform effective coracle recovery, damage (particularly to the coracle hulls) was understandably increased through the lack of previous handling experience. On D+1, it was found that radio Signals starting project instrumentation aboard DD-474 and DD-592 were not received because of a failure of ship’s power; therefore, minima! data was obtained from these ships. Since the target ships were being towed into the lagoon, all project operations aboard were suspended until they were reestablished at their lagoon moors. On D+2, the project performed a complete recovery and survey of all target ships. Complete stripping of coracles was started at the BWA, all samples being processed through the Sample Recovery Center (SRC) established near the Parry Island airstrip to maintain proper contamination control and to insure proper logging of all pertinent data. During the interval between shots, all coracles and instruments were overhauled, recalibrated, and repaired. - Because of the low degree of radioactive contamination, ao Special dc' contamination was necessary. All GITR detectors were recalibrated on a radiation range established on Parry Island. All IC trays were counted in an end-window gamma counter as soon as they could be recovered, decay was followed on a few trays, and the remaining trays were returned to NRDL for further analysis. The GITR tapes from the coracles and the ships were read out on an electronic readout device (GITOUT), a procedure of several weeks’ duration. Site chemistry was limited to beta and gamma decay measurements, and to Cl™ analysis of early fallout samples and cloud samples obtained for the project by Los Alamos Scientific Laboratory (LASL). All further analytical work was performed at NRDL. Project instrumentation aboard the major target ships suffered only minor damage and was overhauled in situ with the exception of the GITR detectors, which were removed for recalibration on Parry Island. 2.1.2 Shot Umbrella. The placement of deep moors for Shot Umbrella commenced on 27 May. By 31 May, the 5 deep moors and 12 of the lagoon moors had been placed. The remaining moors, including two stations on the atoll reef, were placed during the final installation of coracles at the moors. During this period, seven lagoon moors had to be replaced because the _ counterweight on the Dan buoy chafed through the mooring cable. When this trouble was corrected by removal of the counterweight, no further difficulty was experienced with the lagoon moors. Starting on 3 June, coracles in a pre-armed condition were placed at the moors ata rate of five or six a day; these stations were later armed by pulling a lanyard attached to a dead-safe switch that had been installed tn the instrument control box after Wahoo. Ww 53