mechanical advantages he supplies the 

 power required for many critical vehicle 

 functions. In small, shallow vehicles man- 

 power supplies many needs which can be 

 grouped under such functions as push, pull, 

 twist, turn and crank. In some vehicles, the 

 application of manpower is direct and in- 

 volves the following: 



— Orientation of propulsion motors (All 

 Ocean Industries), 



— Control of dive planes and rudders (PC- 

 3 A), 



—Dropping of emergency weights (PISCES 

 II), 



— Water deballasting with hand pump 

 (NALTILETTE), 



—Control of manipulator (ISEKTOIS , SEA 

 OTTER), and 



— Water sampling with hand pump (BEN 

 FRANKLIN). 

 In the majority of deep vehicles, these func- 

 tions are accomplished by pushing a button 

 which activates a pump or motor to perform 

 the same task, but electricity is always in 

 short supply and wherever the opportunity 

 exists to use a mechanical rather than elec- 

 trical component the designer will do so. 

 There are limits, however, to the practical 

 and physical aspects of transferring manual 

 power through a pressure hull by means of a 

 shaft and stuffing box. At 1,000 feet, vir- 

 tually all manually-operated external compo- 

 nents or systems are replaced by electric or 

 electro-hydraulic mechanisms, the only nota- 

 ble exception being the mechanical dropping 

 of emergency weights. In a few vehicles, S£A 

 OTTER and the PISCES series, movement of 

 a simple manipulator and jettisoning of var- 

 ious components is accomplished by man- 

 ually pumping fluid through the hull to at- 

 tain the desired reaction hydraulically. 



PNEUMATIC POWER 



The section "Deballasting and Compressed 

 Air" in Chapter 6 discusses the characteris- 

 tics of compressed air as a power source in 

 submersibles. It will suffice at this point to 

 reiterate that in a great number of the shal- 

 low diving vehicles compressed air is used 

 exclusively as the primary power source to 

 force seawater out of main ballast tanks on 



the surface and from both main and variable 

 ballast tanks when submerged. 



ELECTRIC POWER 



Electric power in submersibles is much like 

 the weather; everybody talks about it, but 

 nobody does much about it. Table 7.1 shows 

 the kinds of electric power sources in 100 

 submersibles; 86 of these use lead-acid bat- 

 teries, 1 uses a nuclear reactor, 2 derive their 

 power from the surface, and the remaining 

 vehicles use nickel-cadmium or silver-zinc 

 batteries. On the other hand, the published 

 literature on energy sources for undersea 

 work abounds with accounts of the potential 

 fuel cell applications. Yet, all subiiiersibles 

 constructed in the seventies and now under 

 construction specify lead-acid batteries. 



This literature imbalance is found in many 

 other areas, e.g-., pressure hull materials and 

 ballasting devices. The authors concentrate 

 on the future, rather than the present. For 

 example, as pointed out above, batteries con- 

 stitute the major power source for all but 3 

 out of 100 submersibles, and lead-acid batter- 

 ies dominate. Yet few can be found which 

 deal with means of improving the output or 

 construction of lead-acid batteries for this 

 type application. There is also a complete 

 absence of reports detailing the means used 

 to distribute this power and their successes 

 or failures. Bits and pieces of advice can be 

 found in a few papers, but a major work on 

 this aspect (lead-acid batteries and power 

 distribution) of submersibles is lacking. As a 

 result, the private builder is left to his own 

 devices in designing electrical circuitry and 

 selecting reliable components. It is not sur- 

 prising, therefore, that historically and cur- 

 rently, electrical malfunctions turn out to be 

 the most common cause of aborted submers- 

 ible dives. 



In a 1970 presentation at the Offshore 

 Technology Conference in Houston, Texas, J. 

 F. Rynewicz (2) made the following state- 

 ment regarding Lockheed's DEEP QUEST 

 and the submersible field at large: 



^'Electrical problems, especially 

 leakage in electrical cables, connec- 

 tors, and circuit breakers, constitute 

 the major area of need for improve- 



310 



