VIII. SUMMARY 



After decades of specialized development for bottom-laid ocean 

 communications cables, an exponential increase in the number of uses and 

 types of applications for E-M cables has left the technology behind the 

 demand. In this study, areas deemed important to cable users were re- 

 searched to determine what the technological capabilities in the field 

 of E-M cables are todav. One result of this research is the identifi- 

 cation of areas lacking in development, or needing improvement, from the 

 point of view of users, designers, and even the manufacturers. 



An E-M cable system starts with a very specific application born 

 out of the necessity to use a single cable for both the electrical and 

 mechanical functions, instead of separate cables to perform these func- 

 tions independently. The two primary areas of concern are the electri- 

 cal design and the mechanical design of the cable. It is from these 

 divergent points of view that problems may be generated. Writing speci- 

 fications for a cable Is not an easy task in view of the real complexity 

 of something seemingly as simple as a cable. Often the user or designer 

 of the cable does not provide the proper design or specifications to the 

 manufacturer, or the cable may be used for a different purpose or under 

 different conditions than those for which it was originally intended. 

 Symposia have been suggested to exchange cable information, while others 

 have suggested that standards and procedure should be established based 

 on past E-M cable experience, future anplications, and potential problems. 

 Others have suggested increased efforts toward the investigation of ad- 

 vanced methods of powering, controlling, and communicating for deep sea 

 systems without cables, such as ultrasonic transmission, self-contained 

 power sources, and fiber optics. 



This study found that a large amount of basic information is still 

 lacking. Thus, the designer of a cable system today must still spend an 

 excessive amount of time investigating such things as materials and manu- 

 facturing capabilities, or he must rely on the manufacturer to supply him 

 with a cable based on a general specification, or use trial and error 

 methods. The various areas of the study are summarized briefly to indicate 

 the deficiencies and the proficiencies of the technology. The current 

 state of the art of E-M cable technology, problem areas, and requirements 

 are summarized below. 



Electrical 



The area that limits any possibility of standardization of cables 

 is the electrical requirements of each application. Each user of an E-M 

 cable has very specific power requirements and even more stringent signal 

 requirements, which are generally inflexible for any one svstem. The 

 size and number of the conductors, the voltage and frequency, and the 

 tolerable power losses are usually unique to each system. Most power and 

 signal requirements are adequately handled by the present technology, with 

 the possible exception of high-voltage transmission. This exception points 

 up an area of need for better conducting and insulation materials. Longer 

 lengths of cable put additional demands on conductors and insulation to 

 achieve a maximum practical transmission distance. The area of exotic 



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