The task of carrying on construction on three islands, although they were separated by but narrow channels, served to complicate construction. The use of DUKW’S to negotiate these channels was a saving factor, Despite the delay in starting construction at this site, completion time was on schedule. The island was turned over to the scientists by midApril. Construction on Runit, the site of the third test, was less complicated than that of the Aomon site. Runit is a narrow island two miles in lenth, presenting some 50 acres of clearance of trees and brush as against 135 acres at Aomon-Biijiri. By 3 April, Runit was completed. Construction on the island of Aniyaanii, exclusive of erection of the photographic tower, was accomplished by the Runit crew. This entailed erection of a generator housing and seismograph housing, the installation of two generators and the laying of pierced plank to complete the light aircraft landing strip. On Parry an air-conditioned control station was constructed. An existing tower was converted to permit installation of telemetering equipment, which recorded data from the three explosions. Two seismograph stations also were installed. This work was completed in sufficient time to meet the scientific requirements for the fist test. INSTALLATION OF COMMUNICATIONS It may be said that the electronics equipment and scientific measuring instruments were the nerve center of the proving ground. The communications system served to coordinate the test operations. This system was installed by the Communications and Electronics Section of Joint Task Force Seven, to the specifications of Task Group 7.1.20 The first task in the implementation of the Communications and Electronics plan was dealt with earlier in this section, the laying of submarine cable. It is worthwhile to note, however, that the paucity of experienced personnel available for this job fostered early consideration of contracting with some commercial company. Security considerations excluded this solution. Examination developed that among the uniformed services, only the Coast Guard offered personnel experienced to do the operation. Accordingly, the services of Lt. Cmdr. Harry E. Rowand were requested and secured, along with enlisted technicians. Upon formation of the cable-laying unit, Task Unit 7.3.6 of Admiral Denebrink’s Naval Task Group, Commander Rowand assumed command. During the planning stages of communications it was determined that the following facilities would be required for the test 15ring phase of the operation: (1) Telephone circuits (radio and wire) between the various shore installations and the three primary ships; (2) Radio intercom facilities between the offices of the scientific group and main staff sections of the Joint Task Force; (3) Radio teletype and coding systems to provide for transmission of Atomic Energy (AEA) “Restricted Data” messages between the primary ships and between theships and the Atomic Energy Commission installations in the United StateS; (4) Technical radio nets to back up the radio telephone system. At this time, AN/TRCl radio telephone equipment was to be used in the primary com*0sec. IXof Annex contAns the detailed Communications reRort. 101 w’ .