During the design phase of the U.S. Navy's 

 Deep Submergence Search Vehicle (DSSV), 

 Lockheed Missiles and Space Company rec- 

 ognized that reliability of so-called standard 

 (Fig. 7.33) external cabling systems was 

 questionable at depths of 20,000 feet. Subse- 

 quently, the Navy funded a design, fabrica- 

 tion and test program for several types of 

 pressure-compensated cable systems. 



According to Saunders (43), present ca- 

 bling systems suffer the following deficien- 

 cies: They are not amenable to analytical 

 design approach; extensive pressure testing 

 is needed to prove design; "standard" compo- 

 nents and assemblies are expensive, large 

 and heavy; and cable assemblies are difficult 

 to assemble, repair, inspect and maintain. 

 The test program was an attempt to over- 

 come these deficiencies through use of pres- 

 sure-compensated cables. 



Six compensated systems were tested and 

 the results compared to the DSRV type of 

 standard cabling system. Briefly, the com- 

 pensated cable consisted of a Tygon tubing 

 sheath with bare wire loosely coiled inside. 

 The various test compensating mediums con- 

 sisted of a petroleum-based hydraulic fluid, 

 electrical box silicone fluid, mineral grade oil 

 and silicone grease. A variety of compensa- 

 tion devices were used, and each of the six 

 systems consisted of a junction box with 

 three cable entries and two cable assemblies 



#20AWG 

 CONDUCTOR 



#16AWG 

 CQNOUCTOR 



»16AWG 

 CONDUCTOR 



Rg. 7 33 Typical power cable construction lor the DSRV 



with a penetrator plug on the end of one 

 cable. 



A wide variety of tests were performed, as 

 the systems were cycled to 13,200 psi, in an 

 effort to gain general information rather 

 than to determine the suitability of one type 

 of compensated system over another. It is of 

 interest to note that, except for one leak, all 

 test specimens met the required perfor- 

 mance criteria. While Saunders expresses 

 the need for further study and component 

 development for specific subsea devices, he 

 draws the following conclusions regarding 

 pressure-compensated cable systems: Depth 

 does not limit their applicability, manufac- 

 turing costs are lower than for standard 

 cables, component costs are lower, testing 

 costs are lower because no pressure testing 

 should be necessary following qualification 

 testing, procurement time is reduced, relia- 

 bility is increased, cable assemblies weigh 

 less, and measured electrical characteristics 

 were equal to or exceeded DSRV cabling. 

 Although the DSSV never progressed beyond 

 the design stage, many of the experimental 

 results were unanticipated and the reader is 

 urged to consult this report for an insight 

 into this approach to submersible cabling. 



As regards reliability of undersea cables, 

 there is revealing testimony in reference (32) 

 which supports the earlier manufacturers' 

 contention that mishandling and misapplica- 

 tion by the user are chief factors in cable 

 harness failure. Lockheed's DEEP QUEST 

 Program Manager, distressed at the high 

 damage rate, established training programs 

 to teach their engineers and technicians the 

 proper methods of handling and carrying, 

 what length could remain unsupported with- 

 out damage, what kinds of containers to use 

 for shipping and proper in-plant storage pro- 

 cedures. Additionally, a very rigorous ship- 

 board inspection program was instituted and 

 supervised by DEEP QUEST s Chief Pilot to 

 assure, among other things, that connectors 

 were tied tight, that people were not using 

 connectors or penetrators as steps and that 

 cables were not allowed to lay loose on the 

 deck. Similar precautions were taken by 

 Westinghouse in its DEEPSTAR 4000 pro- 

 gram. 



One problem in small submersibles is that 

 cables cannot be protected by enclosing them 



354 



