cations for a general-purpose connector most 

 generally applied in undersea application are 

 described in Navy Bureau of Ships MIL-C- 

 24217. Connectors for the civil sector in gen- 

 eral application are supplied by Vector (for- 

 merly Marsh Marine), Joy, Electro Oceanics, 

 D. G. O'Brien, Viking Industries and ITT 

 Cannon Electronics. In addition to those 

 noted, a variety of other companies produces 

 standard and special purpose connectors. No 

 specific point, other than displaying the 

 mind's ingenuity, would be served by de- 

 scribing each connector in detail. For those 

 interested in such details, reference (36) is 

 recommended. For a more general overviewr 

 the results of the DOT program will serve 

 adequately wherein five basic designs were 

 evolved from the multitudes which "... 

 seal the cable and provide the desired 

 electrical continuity between components'' 

 (31); these are: 



a) Cable stuffing tube component penetra- 

 tor 



b) Pressure proof electrical connector 



c) Molded cable penetrator 



d) Molded cable penetrator with insulated 

 backing header insert 



e) Flange mounted polyethylene molded 

 plug penetrator. 



All of these devices (Fig. 7.26) are similar to 

 those noted for electrical hull penetrators. 

 Pressure proof electrical connectors (Fig. 

 7.27) are of major concern because of their 

 more widespread use. Connectors of the type 

 shown in Figure 7.26 offer several individual 

 advantages — e.g., they may be inexpensive 

 and quite reliable — but the major disadvan- 

 tages outweigh the advantages, to wit: The 

 penetrator must be scrapped if the cable is 

 damaged in service, and, most importantly, 

 there is no convenient disconnect point at 

 the component. Numerous other advantages 

 of the pressure proof electrical connector are 

 outlined in reference (31). 



An electrical connector consists of a plug 

 and receptacle assembly. The heart of the 

 connector is the pin and socket contacts 

 which make the electrical junction. The ma- 

 jority of connectors in use today can be di- 

 vided into four types based on construction 

 material. These are: 



a) Metal plug and receptacle 



b) Molded rubber plug and receptacle 



c) Plastic plug and receptacle 



d) Underwater disconnectable connector. 



The following comments regarding the ad- 

 vantages and disadvantages of the above 

 connectors are taken from the DOT Hand- 

 book. 



Metal Shell Conneelor: 



The metal construction which provides a 

 rigid skeleton has demonstrated the greatest 

 degree of reliability on submersible equip- 

 ments. The nature of the design requires 

 more component parts, is heavier and has 

 greater initial cost. However, these disad- 

 vantages are more than offset by a higher 

 degree of reliability and resistance to instal- 

 lation and environmental damage. The 

 added initial cost becomes insignificant when 

 related to overall system cost and the critical 

 role a connector plays in a system's satisfac- 

 tory performance. A single connector failure 

 can abort an entire mission. 



The metal plug shell provides a rigid and 

 adequate bonding surface for the cable seal 

 and thus provides adequate cable strain re- 

 lief at this point. The rigid construction 

 makes possible a greater degree of wire posi- 

 tion control in molding a cable to the plug 

 and, therefore, much less chance of electrical 

 shorts or opens due to uncontrolled migra- 

 tion of conductors during the cable end seal- 

 ing process. The metal shell provides a posi- 

 tive stop for controlled gasket squeeze in 

 seal areas between plug and receptacle and 

 between receptacle and mounting surface. 

 Metal has the necessary strength and dimen- 

 sional stability to provide reliable threaded 

 parts. A metal receptacle shell provides the 

 necessary support for a positive and reliable 

 pressure barrier in case of accidental expo- 

 sure to sea pressure. Metal construction pro- 

 vides for a more reliable mounting of bulk- 

 head types and an additional mounting 

 method, namely a seal weld. An individual 

 insulator in combination with snap-in socket 

 contacts provides good contact positioning 

 for proper mating alignment. Metal bodies 

 are best adapted for positive keying to polar- 

 ize plug with receptacle. Where both plug 

 and receptacle shell are of a nonresilient 

 material, a more reliable coupling can be 

 accomplished. Elastomer compression set 

 and material flow with resulting loosening is 

 not a problem. 



346 



