to ocean use would actually permit simplification of the space and missile 
application because of the superior cooling and shielding provided by the 
deep-ocean water (Beck et al, 1964); Braun, 1965; Beck, 1966). Neverthe- 
less, the necessary demonstration, design, and testing will be expensive and 
require considerable time. 
No less expensive to develop than nuclear power sources would be 
suitable fuel cells. These are also in an advanced state of development for 
space applications and would be made more efficient by the favorable 
environment provided by the ocean. However, use of fuel cells instead 
of a nuclear reactor would introduce an additional logistics problem— 
the transportation of fuel to the work site. An extensive literature search 
indicates that costs and time for the necessary development of fuel cells 
are comparable to those for a small reactor but the resupply problem would 
make them less attractive in the long run. 
A case is made below for use of hydraulic power on the vehicles and 
in their controls. It should be noted that both the reactor and fuel cell power 
sources can supply hydraulic power in a simple, closed system and should be 
considered competitive with surface power systems with some form of power 
transmission to the bottom. 
A primary problem of excavating and drilling on the ocean bottom 
is that of transferring power from the surface to the subsurface operations 
if a bottom-sited power source is not used. To determine how this trans- 
mission of power could be most effectively accomplished, several power 
transmission systems were investigated, and efficiencies and size relationships 
were estimated under pertinent parameters. Electrical, hydraulic, mechanical, 
and pneumatic systems were studied; each was to deliver 100 hp (equivalent 
to a power consumption of 74.6 kw) at a depth of 20,000 feet. The conclu- 
sions drawn would be similar for the systems at 6,000 feet. 
Electrical systems employing (1) three-wire, three-phase alternating 
current or (2) single-conductor direct current with the ocean used as one side 
of the line were considered at several voltages. 
Hydraulic systems using both petroleum-based hydraulic fluids and 
filtered seawater as a hydraulic fluid were compared with pneumatic systems. 
Finally, efficiency of transmission of power from the surface via reciprocating 
and rotating taut steel cables was analyzed. 
The first tentative analysis considers in detail the line losses between 
the surface and the bottom and the probable reliability of the various systems. 
Some predictions of the difficulties and effort needed to develop what appear 
to be the more promising systems are included. 
