Long Distance Telephone Circuits in Cable* 



By A. B, CLARK and H. S. OSBORNE 



This paper first very briefly reviews the history of long distance telephone 

 cables in the United States. A statement is then given of the basis of the 

 electrical design of present day cables, followed by a discussion of the 

 standards applied to cable circuits and the application of cables to the 

 telephone needs of the country. While the present system is satisfactory 

 for the circuits now used in cable up to distances of 1800 miles (3000 kilo- 

 meters) or more, it would not be satisfactory for the much greater distances 

 expected for the future, both for continental and intercontinental service. 

 The paper closes with a brief account of the progress which has been made 

 in the development of a cable carrier telephone system which is expected 

 to be satisfactory for any distances which may in the future be spanned by 

 telephone circuits in cable. 



The authors wish to acknowledge their appreciation of the assistance 

 given them by a number of their associates in the American Telephone and 

 Telegraph Company, particularly Messrs. L. G. Abraham and R. M. 

 Goetchius. 



D 



kURING the last two decades there has been, in all countries 

 which have a large telephone development, a remarkable increase 

 in the use of long distance telephone circuits in cable resulting in the 

 building up of such large networks of long distance telephone cables 

 as those which today cover the continent of Europe and a part of the 

 continent of North America. This paper discusses the technical 

 problems encountered in this development and the solutions applied 

 in the development of the long distance cable network of the United 

 States of America, using this as an illustration because it is the tele- 

 phone plant with which the authors are most familiar. 



Important Cable Development Milestones in the 



United States 



The early long distance telephone circuits in the United States 



were practically all open wire. In fact, great care was exercised in 



laying out open-wire circuits to eliminate the necessity for using even 



short stretches of cable. Cable began to be considered seriously for 



long distance service when loading became available. In 1902 the 



first commercially loaded cable circuits in the United States were 



installed between New York City and Newark, N. J., a distance of 



about 11 miles (17 kilometers). Other cables rapidly followed, until 



in 1906 loaded cables were installed between New York and New 



♦ Presented at The International Electrical Congress, Paris, France, July 

 5-12, 1932. 



520 



