—Increased fatigue life of cables and connectors to 
reduce this most common cause of failure in 
mooring lines. 
—Development of materials for higher strength 
chains and cables. 
—More reliable, longer-life shackles, thimbles, swiv- 
els, and other fittings. 
—Improved line tension measuring equipment 
for monitoring and limiting loads imposed by 
floating platforms on mooring cables. 
—Analyses of the coupling of the motions between 
the platform and mooring cable under the excita- 
tion of wind and sea. 
—More sophisticated sensing and control systems 
for dynamic positioning of large drilling ships and 
barges. Dynamic positioning is relatively new, and 
continual advancement will be required to estab- 
lish its economic feasibility under all conditions at 
sea. 
—Low cost (high production) expendable buoy 
technology including deployment concepts appli- 
cable to large-scale buoy systems for use on a 
global or quasiglobal basis. 
Improved technology is expected to allow 
buoys to be positioned in remote areas to report 
synoptically observations via synchronous satel- 
lites using VHF or higher UHF frequencies. Partic- 
ular emphasis should be placed on improved 
reliability so the service interval can be extended. 
2. Surface Support Platforms 
a. Current Situation Human underseas activity, 
except for military submarine operations, has 
required surface support. Development of sub- 
merged support systems will not negate this 
requirement. 
Today the primary operating cost of deep 
submersibles results from the ships and systems to 
support them. Except for high pressure associated 
with great depths, the greatest and most dangerous 
ocean forces are at the surface with its attendant 
weather and wave system. Great hazards exist for 
the small submersible even in moderate seas during 
launching, retrieval, and transfer of cargo and 
personnel. A few wave lengths below the surface, 
wave effects disappear. 
Avoiding surface effects by using submarines is 
ideal. Long endurance submersibles using nuclear, 
thermodynamic, or other power sources could 
minimize the need for support ships. 
Current surface support systems development 
by the Navy include a new class of ASRs (Figure 
13). These ships, with catamaran hulls, are de- 
signed to support rescue submersibles as well as 
other Navy missions. The ASR is a greatly im- 
proved support platform, but definitely limited by 
wave action in more severe seas. A test support 
ship, the [X-501, will be used for surface support 
of Sealab III (Figure 14). It depends on moorings 
and relatively protected waters to support test 
operations. 
Figure 13. Artist’s concept of first of new 
series of submarine rescue ships (ASR). 
Catamaran hull configuration provides stable 
platform and large working area necessary 
for launching, retrieving, and supporting Deep 
Submergence Rescue Vehicle (DSRV) and 
advanced diving systems. (Navy photo) 
Figure 14. U.S.S. Elk River ([X-501), special 
purpose range support ship first used in Sealab 
III operations, has center well, 65-ton traveling 
gantry crane, deck decompression chambers, and 
two personnel capsules. (Navy photo) 
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