PLANNING AND OVER-ALL PERFORMANCE 13 



water use, the additional container size required for two-way repeaters 

 was of no great moment compared to the advantages of a single-cable 

 system. 



United States Experience 



In the United States, the cable art developed under very different 

 circumstances. There was, of course, need for communication to Cuba, 

 Catalina, Xantucket and other off-shore locations, some of which in- 

 volved conditions similar to those existing around the British Isles. 

 The application of carrier to several of these cables occurred at an early 

 date, but the repeater art was not directed at these shallow water appli- 

 cations. 



For many years, telephone communication to Europe had been an 

 important goal and some thirty-five years ago a specific proposal was 

 made by the Bell System to the Post Office for a single, continuously- 

 loaded, nonrepeatered cable to provide a single telephone circuit across 

 the Atlantic. 



This system was never built, partly because of the economic depression 

 of the early thirties and partly because short-wave radio was able to 

 meet current needs. Cable studies and experiments in the laboratorj^ and 

 field were continued, however, and largely influenced subsequent de^'el- 

 opments. It was at this time that the physical structure of the cable now 

 used in the transatlantic system was worked out. It was also at this 

 time that the harmful effects of physical irregularities in the cable were 

 demonstrated. As cables are laid in deep water, high tensions are devel- 

 oped which unwrap the armor wires that normally spiral about the 

 central structure. As tension changes during the laying process, twisting 

 and untwisting occurs which is harmless if distributed along the cable. 

 But obstructions in the cable which prevent rotation, or any other pro- 

 cess such as starting and stopping of the ship which tends to localize twist- 

 ing, are likely to cause kinking of cable and buckling of the conductors. 



By 1932, electronic technology had advanced to a point where serious 

 consideration could be given to a wideband system with numerous long- 

 life repeaters laid on the bottom of the ocean and powered by current 

 supplied over the cable from sources on shore. 



The hazardous effects of obstructions in the cable, demonstrated in 

 early laying tests, indicated that the chances of a successful deep-sea 

 cable would be greatest if the repeaters were in small-diameter, flexible 

 housings which could pass through laying gear without stopping the 

 ship and without restricting the normal untwisting and twisting of the 



