The Navy is modifying nuclear submarines and 
one diesel sub to test carrying the DSRV piggy- 
back—a promising beginning of an all-weather and 
under-ice submersible support system divorced 
from the hazards of the ocean surface. 
Through its own laboratories and in association 
with academic institutions, the Navy built FLIP 
and SPAR, two deep draft, surface stable platform 
vessels for oceanographic and acoustic research. 
They have proved very successful as stable plat- 
forms; FLIP is reported to have experienced 
vertical motion of only three inches in the 
presence of 35 foot waves. 
The following are important operations per- 
formed by stable surface platforms: 
—Vehicle handling. Launching and retrieving man- 
ned and unmanned vehicles involves handling 
heavy masses through a very rarely calm, ocean- 
atmosphere interface. Equipment and techniques 
must be improved before launch and retrieval can 
be accomplished safely and routinely. Submerged 
retrieval (involving underwater docking) is a possi- 
bility being developed for the Navy’s Deep Sub- 
mergence Rescue Vehicle. 
—De-ballasting. Mining, construction, and salvage 
operations at continental shelf depths may require 
large quantities of high and low pressure air for 
de-ballasting operations. Routine provision of air 
supplies at depth has not been accomplished. 
—Diver support. A satisfactory surface system is 
required to continuously support extended satura- 
ted diving operations at sea. 
—Logistics. Surface platforms must be supplied 
with materials and personnel while on station. 
At-sea transfer techniques during severe weather 
must be developed; vertical replenishment with 
helicopters offers a possible solution. Platforms 
may be required to provide potable water, electric 
power, high pressure air, heat, supplies, quarters, 
subsistence, and medical care to personnel working 
at the site below. 
b. Future Needs In the past there has been a 
strong inclination to adapt off-the-shelf equipment 
to needs of surface support vessels and platforms, 
resulting in repeated failure of equipment to 
function in an environment for which it was not 
designed. A specially designed stable surface sup- 
VI-54 
port system could provide reliability, relative 
freedom from weather and sea state conditions, 
safer and less costly support, and availability. 
The trend is toward improved support capa- 
bility. Development of new platforms designed 
specially for all-weather submersible support 
whether by submarine or by deep-draft surface 
stable vessel, is strongly encouraged. By 1980, a 
more subsurface Navy and a proliferation of 
commercial submersibles will dictate improved 
support systems capability. Work at continental 
shelf depths and deeper will require surface 
support ships where surface conditions are favor- 
able and where the underwater task is such that a 
surface supported system can be deployed more 
rapidly or economically. For many shelf opera- 
tions large submersibles may perform tasks with- 
out surface support. 
For underwater tasks requiring surface support, 
a variety of ships will be used. It is unlikely that a 
single multipurpose platform could perform all 
support functions. A need exists to investigate 
platform requirements including selected model 
studies and ancillary equipment development. 
Various stabilization systems are already in use 
(e.g., stabilizers, tuned ballast, hull shaping) to 
decrease motion of ships under way. However, 
little has been accomplished for stationary plat- 
forms other than for FLIP and SPAR. Such 
stabilization techniques as mass traps should be 
considered. The traps are formed by two long 
plates held apart at intervals; water inside is 
trapped, providing an apparent mass that dampens 
the motion of the platform. 
A system to maintain a surface platform’s 
position for extended periods with respect to 
geographic location or bottom reference will be 
required. Project Mohole did much for dynamic 
positioning. 
A variety of lifting and emplacement require- 
ments will be put upon future platforms. Available 
equipment or technology provides for lifts up to 
200 tons. Winches stabilized to counteract ship’s 
motions during a lift operation have been thor- 
oughly studied. For heavy lift or emplacement in 
excess of 200 tons, a large floating crane or similar 
device must be evaluated. 
3. Conclusions 
Mooring and anchoring techniques and hard- 
ware are inadequate for the heavy load and long 
