CHAPTER 8 



COMMUNICATIONS 



The main essential of communication between 

 two persons is that the language they use must be 

 understandable to both. Not only must one person 

 be able to express himself clearly, but the other 

 man must b3 able to comprehend what is commiini- 

 cated. 



Realizing that many problems are encountered 

 in corrLTiuQications, the Navy has adopted certain 

 standard methods and practices to minimize 

 errors and misunderstandings in message trans- 

 mittal and reception. Many of these standard 

 procedures are used by other allied services. 

 They are invaluable in conducting joint inter- 

 national operations. The phonetic alphabet has 

 been adopted by all allied forces for combined 

 operations. 



In this chapter you will become acquainted 

 with some of the Internal and external communi- 

 cation systems used aboard ship. Additionally, 

 you will learn correct operating procedures for 

 radiotelephone and underwater telephone com-- 

 munlcations. Because the phonetic alphabet and 

 sound-powered telephone procedures are covered 

 in Basic Military Requirements , NavPers 10054, 

 they are not included in this text. 



INTERNAL COMMUNICATIONS 



Most men in the Navy, regardless of rate, 

 are familiar with internal communications. Sonar 

 Technicians, especially, have occasion to use 

 several types of systems available for trans- 

 mitting sonar Information. It is almost Impossible 

 to conduct attacks on enemy submarines or ships 

 without some method of internal communications. 

 On a destroyer, sonar control may be located 

 below decks, on the bridge level, or In some 

 other section of the ship (depending on the type 

 and class of ship). Because it is remote from 

 the bridge, some means of communication must 

 be established between the bridge and sonar 

 control. This requisite is accomplished by uti- 

 lizing one or more of the internal communica- 

 tion systems. Shipboard circuits Include MC 



(loudspeakers) circuits, sound-powered phones, 

 and automatic devices. These devices are remote 

 indicators, and are used to transmit bearings, 

 ranges, course orders, firing orders, and other 

 data. 



When sonar contact is made, the bridge 

 usually is informed over an MC system. By 

 this method, all stations concerned are alerted, 

 and sound-powered phones are then manned to 

 eliminate excessive noise levels caused by the 

 constant use of loudspeakers. The ASW officer 

 is directed to make the attack. His course 

 orders to the bridge are relayed by automatic 

 electromechanical devices to direct the helmsman 

 in maneuvering the ship to the firing position. 

 As the ship reaches the firing point, signals or 

 verbal instructions to fire must be transmitted 

 to the weapons stations for firing weapons at 

 the correct time. 



SOUND-POWERED PHONES 



The shipboard voice communication system 

 used most extensively is the sound-powered 

 telephone (S/P) network. It consists of primary 

 battle circuits JA to JZ, with auxiliary and 

 supplemental circuits for use if a primary 

 circuit is damaged. The degree to which these 

 circuits are manned varies. Few circuits are 

 used under normal peacetime cruising condi- 

 tions. During general quarters, when all battle 

 stations are manned, all circuits may be used. 



Of primary concern to the Sonar Technician 

 are the JA, JP, and JS circuits. The J A, the 

 captain's battle circuit, is used for transmitting 

 orders to key control stations and exchanging 

 vital information with those stations. Weapons 

 control information is passed over the 8JP 

 circuit. The other S/P circuit you wiU probably 

 man is the 61JS. It normally is used as a 

 one-way system to provide contact range and 

 bearing and other data to UB plot, CIC, and the 



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