Table 11. Causes of Cable Breaks 



Cause 



No. of Breaks 



% of Total Breaks 



a' 



b2 



a 



b 



Trawler 



Chafe-corrosion 



Kink 



Biological 



No report 



Electrical maintenance 



Other (ship anchor, kink, etc.) 



Unknown 



127 



95 



18 



9 



24 



96 

 61 



2 



20 

 16 

 8 



47 



34 



7 



3 



9 



47 

 30 



1 



10 

 8 

 4 



Total 



273 



203 



100 



100 



'' Data derived from Western Union Cable History Study, British Continental 

 Shelf (Allen, 1962) and includes break data for years 1930-1960. 



^Data derived from a compilation of break history of telegraph cables at all 

 depths in the North and South Atlantic Ocean. Period covered is 1959-1962. 



Cable Configuration 



The cable configuration defined by various trade-offs is a multiple 

 cable, concentric-stranded copper conductor that is insulated with poly- 

 ethylene, shielded, and protected by armor and jacket to meet the conditions 

 of the ocean environment. A typical cross section of the marine cable 

 selected is illustrated in Figure 18. Table 12 presents physical characteristics 

 of selected marine cables. 



Cable Connectors 



There are several mechanical and electrical problem areas associated 

 with underwater cable connectors and penetrations for the transmission of 

 electrical power to loads encapsulated in a pressure hull. The mechanical 

 problems involve watertightness, mating or connecting and disconnecting 

 underwater, material compatibility, and strength. The ability to achieve the 

 current-carrying capacity at the required voltage with minimum contact 

 resistance through the connector is the major electrical problem to be 

 resolved. 



56 



