CHAPTER IV, SECTION 7 A direct line telephone system was in existence at Eniwtok Atoll with exchanges located at sites Elmer and Fred. To meet the needs of OPERATION CASTLEit was necessary to in- Elmer Ursula — one chief operator and eight operators — two operators; relief operator stall an exchange at Ursula and connect this to the existing system. At other sites, field phones connected through the nearest exchange were Tare provided from Elmer — one chief operator and two new network was laid with exchanges located at camp sites. This system was first used in November 1953. There was no connecting line between the two atoll systems. Charlie Fox Nan — three operators — three operators provided as required. At Bikini Atoll an entirely operators — three operators With the exception of the exchange at Elmer, the systems as installed were adequate. the exchanges, for reasons of economy, were man- During busy hours at site Elmer, seated operators answered calls and men standing behind them disconnected completed calls. The traffic figures during the peak periods indicates that follows: circuits available. This extreme usage indicates an enlarged exchangeis required to handle peak period traffic for a future operation of the size of CASTLE. Figure 4-36 shows the exchange at Elmer. During construction and post-test periods, ned only during the nine hours of the scheduled work day. During operational phases the services were generally extended so as to provide 24-hour continuous service. The telephone exchanges were staffed during the peak of operations as Figure 4-36. this exchange approached 100% usage of the Telephone Exchange - Site Elmer Page 4-51