efforts must be directed toward solving the primary near-term 

 problems; which are decompression, communications, and thermal 

 protection. 



Seafloor Engineering 



This technology area involves the design, construction, and 

 maintenance of fixed ocean installations. The long term goal is 

 the capability of performing any construction task on or in the 

 ocean floor which the Navy may require. Major technology de- 

 ficiencies may be divided into three areas: Site Selection; Site 

 Preparation and Construction; and Structures and Structural Sub- 

 systems. For site selection we need to be able to determine bot- 

 tom topography, sediment strength, sediment stability, turbidity 

 potential, seismic activity, current and wave forces, environ- 

 mental corrosion potential, and biological fouling potential. Site 

 preparation and construction require development in power source 

 and transmission capability, foundation design criteria, bottom 

 stabilization equipment, earth moving equipment, drilling and ex- 

 cavating equipment, lifting and positioning systems, and under- 

 water construction tools. For structures and structural subsys- 

 tems we require structural design criteria, ingress/egress systems, 

 inexpensive high strength structural materials which are easy to 

 fabricate and resist corrosion, and massive operational power. It 

 must be emphasized that seafloor engineering 



represents a major void in our technical knowledge which will re- 

 quire major resource application. 



An intermediate and long-term objective of the Navy is develop- 

 ing technology for undersea habitats. Although there is no specified 

 Navy requirement for a habitat, this wiU be an inherent part of any 

 mission which requires long term seaflcor operations. As part of 

 an effort to identify engineering constraints where further R&D will 

 be required, the Navy has evaluated several concepts for manned 

 habitats at a depth of 6000 feet. The "rocksite" habitat concept has 

 also been evaluated, which would utilize caverns hollowed out of the 

 ocean floor. This is a promising idea for future, large habitats, 

 and development effort has been initiated which will lead to this 

 capability. Under a Navy contract, industry recently completed a 

 study of one-atmosphere, manned underwater stations; the study 

 compared concepts and provided production cost estimates for 

 different habitats at different depths. The study also identified tech- 

 nical areas which require further R&D, and this, in general, confirmed 



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