compressive, torsion^ an d shear loads and provide overall and local struc- 

 tural stability. 



4. Structural Analysis . Established analysis methods of working stresses , 

 cracking strength, ultimate strength, elastic and plastic deformations, 

 and stability — based on behavior of materials and of structural elements — 

 will be required to analyze the OTEC structure. Other methods such as model 

 testing, surveys of existing structures, and probabilistic design may need 

 to be employed. Consideration will need to be given to time-dependent 

 design for fatigue, creep, and relaxation, and to change to material properties 

 with time. 



5. Construction Methods . To construct large concrete structures methods 

 need to be available to construct in a floating mode in shallow or deep 

 protected waters. Also, open sea assembly of large floating components 

 may be required. Total time of construction should be minimized. 

 Variable positive buoyancy will be required during construction and 

 deployment of the platform and the cold water pipe. The concrete anchor, 

 if used, will require positive buoyancy during tow-out, slight negative 

 buoyancy during lowering, and then heavy selfweight or engagement 

 to the seafloor; this may require the capability to fill the anchor with 

 grout or concrete at great depths by remote methods. 



6. Availability of Resources . Size dominates the 

 requirements for manpower, materials, and facilities. Concrete is not as 

 labor intensive nor as demanding as steel construction for sophisticated 

 skills; however, skilled and unskilled labor will be needed, probably 

 around the clock. Cement, aggregates, fresh water, reinforcing 

 and prestressing steels, and forming materials must be available at, or 



