No. of Tapes Receivinq Tape Transmitt~ Tape Receiving ~ (u 600 AGC-7 AV-L AV-5 (2) 600 AV-4 AGC-7 AV-5 (3) &x) AV-5 AGC-7 AV-4 (4) AGC-7 Los Alamos (5) Los Alamos MC-7 (6) m AV-4 Los Alamos (7) 400 Los Alamos Al?++ (8) 400 AV-5 Los AbllOS (9) 400 Los Alamos AV-5 d Wstems (1) through (3) were to be used for both three-way conference and classifiedmessages between the ships. Systems (4) through (9) provided coding facilities for Atomic lhergy Commissionmessages between the ships and Los fbmos. The number of tapes were based on an estimate of the amount of traffic plus a large safety margin. Half of the tapes in each system were ordered to arrive by 15 February 1948, the remaining half to be delivered by 1 March 1948. On 20 November 1947 a request was submitted to the Atomic Mergy Commission for a leased teletype lib frombs Alamos to the Presidio of San Francisco,major relay station in the Amy Command and Adminis- trative Net (ACAN). This circuit was required to provide a continuous traffic to and from the forward area and to bypass the points noxmall.yinvolved in passing messages into the Amy 42 Section XI .