selfpropelled, they have been used for deep ocean 
search, survey, and research. Examples include the 
Naval Research Laboratory’s towed search system 
used to locate and identify much of the wreckage 
of the submarines Thresher and Scorpion at about 
8,500 feet and the commercial ocean bottom 
side-scanning sonar platforms. 
A self-propelled, torpedo-like instrument pack- 
age with a preset internal guidance system has 
been developed with 14,000-foot depth capability 
for the Navy. The probe, 122 inches long and 20 
inches in diameter, is launched from and tracked 
acoustically by a surface ship. The system has been 
used for oceanographic and acoustic research— 
gathering data on sound velocity, thermal proper- 
ties, and other physical properties on magnetic 
tape. Sinking instrument packages, launched from 
a ship and later recovered when ballast or an 
anchor is released, are another example of a 
successful unmanned submersible platform. 
b. Future Needs As more efficient underwater 
observational equipment and tools for underwater 
cutting, welding, grappling, hooking, drilling, and 
controlled lifting become available, a vastly ex- 
panded era of undersea construction, salvage, 
mining, and recovery will evolve through use of 
unmanned and tethered vehicles and platforms. 
The state-of-the-art has progressed well, making 
possible design and construction of a wide variety 
of equipment for special application. Further 
development is needed to improve endurance, 
accuracy, control, reliability, compactness, manip- 
ulation, and depth capabilities. 
Gross bottom reconnaissance for site selection, 
geological searches, geodetic surveys, and biolog- 
ical sampling will require a variety of unmanned 
instrument platforms. In some cases, multipurpose 
systems may be a less expensive, quickly available 
interim substitute for manned submersibles. 
An advanced sea elevator, derivative of the 
diving bell, may effect transfer of man and 
materials from surface support ships and platforms 
to deep ocean installations on or in the sea floor. 
It might carry as many as a score of men and 
supplies to depths as great as 20,000 feet. Eventu- 
ally, its function may be assumed by transport 
submersibles, free from severe waves and weather 
and saving a step in materials handling. The sea 
elevator also may be displaced or supplemented by 
pipelines, air lifts, conveyors, and other mechan- 
ical equipment. 
VI-88 
Undersea construction and salvage will require 
heavy duty work systems—the counterparts of 
dredges, power shovels, bulldozers, tractors, pave- 
ment layers, trucks, pile drivers, plows, drills, and 
cranes. Cable controlled or cable towed devices 
will be hampered and endangered by obstructions, 
nearby traffic, and concentration of similar devices 
at a given work site. The hazards of cables suggest 
wireless control links from the control station to 
the device. An alternate approach might be small 
manned submersibles to serve as control cabs from 
which operators direct and monitor large work 
devices. 
The competitive marketplace or comparative 
studies for military systems will determine which 
devices—manned or unmanned—will best serve 
particular needs. 
3. Transport and Support Submarines 
a. Current Situation Transport submarines have 
been considered seriously for commercial use from 
time to time. In contrast to surface vessels having 
speed, safety, scheduling, and passenger comfort 
governed to a large extent by weather, submersi- 
bles can operate in an environment essentially 
quiet and predictable. 
With the advent of nuclear power, advanced 
structural materials and fabrication techniques, 
and development of submersibles for military 
applications, the technical and economic feasi- 
bility of transport submarines continues to im- 
prove. For transoceanic voyages, the transport 
submarine has been suggested seriously as a carrier 
of bulk liquids weighing less than water. 
A market will exist for recreational submersi- 
bles with large viewing ports if costs are not too 
high. A submersible recently was a top tourist 
attraction in Lake Geneva even though the bottom 
there is quite unspectacular. 
b. Future Needs Whereas some products recov- 
ered from the sea will be transported via pipelines, 
conveyors, and surface vessels, submarine cargo 
carriers probably will be needed between offshore 
production sites and such intermediate points as 
undersea processing stations, storage tanks, and 
surface platforms. A strong need will exist for 
submersible support submarines as high endurance 
motherships for deep operating manned or unman- 
ned submersibles engaged in search and rescue, 
wide-area ocean surveys, site selection, communi- 
