that the connection hardware must provide the compromise. A good example 

 is the area of structural support for the electrical connections. The 

 connector needs to be very rigid to provide good alignment during mating 

 operations and prevent breakage or bending while in operation, but if 

 the connector becomes too large and -massive it can be incompatible with 

 cable handling equipment, or may represent a source of reflections for 

 shock loads in the cable or otherwise upset the cable dynamics. The 

 solution is to incorporate flexible strain relief and damping into the 

 connector cable termination design. 



Thus, it appears that the connectors and other attached cable hard- 

 ware offer the greatest opportunity for design flexibility of any of the 

 overall E-M cable system components. Part of the reason for the design 

 flexibility is simply that E-M cable hardware has not been as thoroughly 

 developed as the cables themselves. The state of the art in cable ter- 

 minations such as connectors, penetrators, swivels, strain reliefs, and 

 conductor breakouts is considerably behind the state of refinement asso- 

 ciated with the cables, especially as regards high power. There are 

 several commercial sources capable of designing and manufacturing high- 

 strength, high-power E-M cables for deep ocean use, but the choice of 

 associated hardware is very limited and is largely untested or unreliable. 

 Some examples of operational systems follow. 



The NCEL DOTIPOS and Seafloor Deep Corer are fairly typical of 

 present applications of E-M cables requiring high power and high strength. 

 It is significant that neither connection system is very flexible, and 

 both must be installed in air. 



The inability to make reliable wet connectors precludes some desir- 

 able installation and construction techniques and adds unnecessary hand- 

 ling requirements for the cables. For example, the NCEL SEA CON I struc- 

 ture was towed to the site with power cables attached and floated astern 

 on spools because there was no reliable way to attach the cables under- 

 water at the site. Poor reliability of high-power connection hardware, 

 combined with the inability to attach or repair the connector and pene- 

 trator hardware in the field makes cable' reliability even more critical. 

 If a cable defect could be simply removed and replaced with a connector 

 while at sea, many cable expenses would be reduced and overall system 

 down time would be greatly curtailed. 



In applications requiring lower voltage or somewhat less strength, 

 the connector hardware has proved to be more successful. Most of the 

 smaller items are fully potted in, relying on the strength of the bond- 

 ing by epoxy, polyurethane or neoprene compounds to provide support for 

 the electrical components, waterb locking of the cable, and a smooth grip 

 on the cable strength member. The units are simpler, smaller, more re- 

 liable, and expendable if required. Many are field- installable. These 

 are generally similar in design to those described in Reference 1 and 

 are primarily used for carrying signals or low-level power. Their primary 

 vulnerability lies in the care in handling exercised by deployment crews. 



"Wet" connectors have experienced much more difficulty than dry 

 connectors because of the complexity of the mechanism used to wipe sea- 

 water from the male pins as they enter the female half. Experimental sys- 

 tems do function reliablv at shallow depths for the first two or three 

 matings, but then seawater leakage begins to degrade the mineral oil 



45 



