of underwater power systems selected for immediate development are 

 presented together with budget cost estimates. A recommended research 

 and development program, based on the findings of this study program, is 

 included for those system elements considered beyond the current state of 

 the art. 



The constraints and assumptions applied to the study program on 

 underwater power systems include 



1. Power levels stated shall be at the load module terminal point. 



2. Usable power at the load module shall be defined as 480 volts, 

 3 phase, 60 Hertz, for a single, nondistributed load. 



3. The load module shall be assumed to contain such electrical loads, 

 as lighting systems, motor-driven operational equipment, environmental 

 control systems, and communications or electronic systems. 



4. Protective needs shall be restricted to the power transmission 

 system and shall not include mission requirements of the load module. 



5. Emergency power levels and type of energy source shall be defined 

 by the power transmission system requirements and not by the mission 

 requirement of the load module. 



The results established in this paper are based on the assumptions and 

 constraints described above, and are only intended to provide guidance in 

 making sound management decisions on the future development of underwater 

 power systems. 



ENVIRONMENT 



An underwater power transmission system is subject to all ocean 

 environmental conditions. The effect of sea states, ocean currents, bottom 

 sediments, temperature variation, salinity, and marine life must be considered 

 in defining design parameters for power system elements. The selection of 

 cable routes and sites for underwater structures depends on a knowledge of 

 bottom profiles and sediment types. Available data and information on the 

 ocean environment are summarized in this section and evaluated as to their 

 effect on the underwater power transmission systems and associated elements. 



Sea-Air Interface 



Surface conditions for a particular area of ocean deployment are 

 important design parameters in the development of an underwater power 

 transmission system. Hull shapes for surface-tendered systems, as well as for 



