V. ELECTRO-MECHANICAL CABLE TERMINATIONS 



One of the most complicated and technically difficult engineering 

 interfaces in major ocean systems is the transition from an E-M cable to 

 the vehicle or structure which it serves. It is, therefore, one of the 

 most unreliable. 



The primary function of an E-M connectors is to provide electrical 

 and mechanical integrity through an E-M cable -junction. It may also 

 provide a watertight interconnection point for a harness at the outboard 

 component and at a hull penetrator. The connector also seals the cable 

 at these enclosures and also prevents the cable from being forced into 

 enclosures due to the hydrostatic pressure at various ocean depths. There 

 are many design considerations which apply to E-M connectors. These are 

 as follows : 



1. Connector types and sizes 



2. Configuration - connector 



3. Plug design 



4. Receptacle design 



5. Pin and socket contact design 



6. Fastening - plug to receptacle 



7. Sealing - plug to receptacle 



8. Connection - conductor to socket contact 



9. Insulation and seal - pin contact 



10. Insulation and seal - socket contact 



11. Seal - cable to plug 



12. Electrical requirements 



13. Cable strain relief 



14. Material selection 



15. Corrosion properties 



16. Fabricability 



17. Safety 



18. Strength of mechanical connection 



19. Stiffness 



20. Thermal properties 



21. Cost 



Design Practices 



The interface with connectors and penetrators has been given low 

 priority in most cable design efforts. The resulting cable configurations 

 impose constraints on hardware design instead of vice versa. For example, 

 cable hardware must fit smoothly into the mechanical strength member of 

 the system (usually an exterior armor) and efficiently transmit all the 

 complicated tension, flexure, and torsional loads imparted to the cable 

 while at the same time isolating the fragile electrical components housed 

 in the core of the system. Because of stress concentrations due to 

 mechanical loads, damage frequently occurs at or near the connections. 



Despite the many engineering problems associated with the cable- 

 structure interface, most cable designers are so constrained bv the basic 

 cable requirements that they have historically given insufficient 



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