left the Zero Island and proceeded to Parry by way of each intermediate Zero Island, At each intermediate Zero Island the timing stations were checked and all power turned off. 1800 Evacuation of the lagoon was completed except for the USS Mt. McKinley, USS A1bemarle, USS Curtiss, USS Bairoko, two AVR’S and a few miscellaneous small craft. The final muster of personnel was made and reported to CJTF-7. After checking control circuits in the control station on Parry the firing party plus Mr. Hedberg and his two diesel opeartors and a medical officer returned to the Zero Island on the AVR’S. 2330 The firing party made final adjustments to experimental equipment at the timing station. Dr. Shonlca made final adjustments of equipment at the gamma stations. II-DAY 0015 The firing party proceeded to the tower cab; closed the safety switches; tested the patch cords; inspected the firing, arming, and power-on relays, and connected the patch cables and various experiment cables to the bomb. Upon completion, the tower cab was locked. 0100 All vehicles to be used by there-entry party were parked at the end of the island in prepared shelters. 0130 The final safety switch on the Zero Island was closed. 0200 All personnel were evacuated from the Zero Island by the AVR’S to Parry. 0300 The firing party arrived at the Control Station. Firing and timing circuits were energized and the control station clocks were synchronized. 0446 A final weather briefing was held for General Hull, Capt, Russell and Dr. Froman. we firing party was cleared to proceed with final operations. .H—70 reins. to Hal min. Colonel Preuss broadcast a test radio call on the Task Force time signal frequency of 3000 kcs. and gave time signals at minus one hour, minus thirty minutes, minus ten minutes and minus one minute. H-60 H-30 reins. The USS Tucker, a destroyer which had been keeping surveillance over the Zero Island, departed its station off Zero Island. Minus one hour signal was given to Hartmann’s equipment. reins. Final safety switch was closed. H—15 reins. Upon instructions from Dr. Froman, who had received General Hull’s approval, Dr. Graves started the sequence timer. Mr. Henderson gave the minus 15-minute signal to the Fitzwilliam group. H—5 reins. All task force personnel were instructed Zero Island. to put on goggles or face away from H—30 sees. to H—10 sees. Colonel Preuss broadcast the minus 30 seconds, minus 20 seconds and minus 10 seconds time signals by means of a gong operated by the sequence timer. H—25 sees. Power-on contactor was closed. H-5 sees. Arming contactor was closed. H-Hour. Firing contactor was closed and the bomb detonated. 135 . ,+ > .