A Transatlantic Telephone Cable* 



By H. A. Affel 



Assistant Vice President, Bell Telephone Laboratories 



In the fall of 1955 telephone communication was established for 

 the first time across the Atlantic by means of a submarine cable. In 

 the summer of 1956, when weather conditions permit, a second cable 

 will be laid to provide the return transmission paths for the speech 

 channels. The new cable system will then become a reliable addition 

 to the global telephone network which links the continents. 



In the summer of 1955, the British cable ship Monarchy with hun- 

 dreds of miles of cable stored in its hold, set out from Newfoundland 

 shores in the direction of Scotland to lay the first section of the new 

 telephone cable. Somewhat less than a hundred years ago the old 

 Great Eastern set forth from Ireland westward toward Newfoundland 

 to lay the fii-st successful transatlantic telegraph cable. 



Superficially, the old telegraph cable and the new telephone cable 

 would not look much different in the process of paying out over a large 

 sheave on the bow or the stern of a ship, but at this point the similarity 

 ends. In the case of the first crossing, the cable provided one very 

 slow-speed telegraph channel — at the most a few words per minute. 

 The new cable will provide 35 talking paths. If employed exclusively 

 for telegraphy, it would yield more than 500 high-speed telegraph 

 channels having a total capacity of 30,000 words per minute. This is 

 considerably more than now derived from all existing transatlantic 

 cables or, indeed, all the deep-sea submarine telegraph cables in the 

 world. 



The improvement in information-transmitting capacity is a rough 

 measure of the advance in performance that the new cable represents. 

 In detail, a centm-y of technical progress lies between the two projects. 

 Tliis would be more evident if one opened up the cable to examine the 

 insides, or if one waited until, in the course of paying out the cable, 

 there appeared a bulge in the new structure for a distance of some 

 20 feet. But this is getting ahead of the story. 



* This article is based largely on a detailed technical description of the same 

 title by Mervin J. Kelly, Sir W. Gordon Radley, G. AV. Gilman, and R. J. Halsey, 

 which was delivered as a paper in the spring of 1955 before the British Institution 

 of Electrical Engineers and the American Institute of Electrical Engineers, 

 published in Electrical Engineering, vol. 74, No. 3, 1955. 



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