merged and 2,000 kWh surfaced. Both de- 

 signs are shown in Figure 7.16. 



POWER DISTRIBUTION 



Few submersible components receive more 

 attention than the penetrators, cables and 

 connectors used to distribute electric power. 

 The reason is clearly evident when the per- 

 formance of submersibles is reviewed: These 

 components range in reliability from mar- 

 ginal to deplorable. One might wonder why 

 this inadequacy was not discovered in the 

 near half-century of military diving before 

 the advent of the manned submersible. The 

 answer, in part, resides in the large size of 

 fleet submarines relative to submersibles. A 

 military submarine carries its power and 

 propulsion machinery within the hull, and 

 except for sonar devices, communication an- 

 tennae and depth sensors, very little else 

 penetrates the hull. More importantly, the 

 WWII submarine, except in emergency, 

 dived no deeper than about 300 feet; at this 

 depth the requirements for a successful pen- 

 etrator are considerably relaxed. From an 

 electrical point of view, a manned submers- 

 ible is a submarine turned inside out. Indeed, 

 in some vehicles the majority of electrical 

 hardware is external to the pressure hull 

 and subject to every transgression in the 

 deep-ocean's arsenal. 



One of the most beneficial aspects of the 

 DSSRG Report to both the military and civil- 

 ian submersible builders was the illumina- 

 tion of problems associated with power dis- 

 tribution and the steps taken to identify, 

 categorize and remedy these problems. One 

 of these steps was establishment of the Deep 

 Ocean Technology (DOT) program in 1966 

 under the Chief of Naval Material, and one 

 of dot's most significant contributions is 

 the Handbook of Vehicle Electrical Pene- 

 trators, Connectors and Harnesses for Deep 

 Ocean Applications (31). 



Based on an exhaustive investigation into 

 past and present penetrators, connectors 

 and harnesses (cables) used in deep submer- 

 gence, the Handbook presents the factors 

 involved in design and development of these 

 components and includes the advantages 

 and limitations of designs which have seen 

 application. The Handbook serves not only 



the designer of future submersibles, but the 

 operator of present vehicles as well. Use of 

 the information therein could avoid some of 

 the major obstacles to an otherwise success- 

 fully designed vehicle. 



Owing to the comprehensive, wide ranging 

 nature of the Handbook, it would be redun- 

 dant herein to relate the many and varied 

 problems encountered along the way to relia- 

 ble or even quasi-reliable electric compo- 

 nents. Hence, this discussion will only high- 

 light and broadly define the nature of the 

 component and its application. 



Electrical Penetrators 



An electrical penetrator serves to pass 

 power or signals through the wall of a pres- 

 sure-resistant capsule, e.g., pressure hull or 

 battery pod. In this role it must satisfy two 

 collateral duties: 1) Seal and insulate the 

 thru-hull conductors, and 2) preserve the 

 hull's watertight integrity under both nor- 

 mal and abnormal (short circuit) conditions. 



Some 33 companies in the U.S. manufac- 

 ture electrical penetrators and connectors; 

 the variation in design and components pre- 

 cludes any one schematic representative of 

 the electrical penetrators. 



Consequently, the penetrators described 

 are selected from various depth ranges 

 merely as an introduction to past and pres- 

 ent technology. 



ASHERAH, a 600-foot submersible, uses a 

 penetrator incorporating the stuffing-tube 

 type of seal which was one of the first de- 

 signs used in military submarines (Fig. 

 7.17a). Pressurization of the materials to ob- 

 tain a seal is accomplished by tightening the 

 inboard gland nut. One limitation to a jam 

 type of seal such as this is determining the 

 correct amount of pressure to apply which 

 will prevent the cable from extruding into 

 the hull yet not damage the cable and which, 

 at the same time, will assure watertight 

 integrity. Repressurization is required from 

 time to time to compensate for the compres- 

 sion set of the packing and cold flow of the 

 conductor jacket material. The penetrator 

 used by Beebe (which carried two power 

 conductors and two telephone cables) in the 

 BATHYSPHERE followed the stuffing-tube 

 principle. 



338 



