PREFACE 



The U. S. Naval Civil Engineering Laboratory is conducting a research program 

 to determine the effects of the deep-ocean environment on materials. This research 

 will be of great value in establishing the best materials to be used for deep-ocean 

 construction in the Navy's conquest of "inner space." 



A Submersible Test Unit (STU), on which many test specimens can be mounted, 

 was designed for the purpose. The STU can be lowered to the ocean bottom and left 

 for long periods of exposure. Planned exposures range from 4 to 48 months at depths 

 of 2,500 to 18,000 feet. 



Thus far, two deep-ocean test sites have been selected. Test Site I (nominal 

 depth of 6,000 feet) is approximately 81 nautical miles southwest of Port Hueneme, 

 California. Test Site II (nominal depth of 2,500 feet) is 75 nautical miles west of 

 Port Hueneme. Additional test sites at depths of 12,000 and 18,000 feet will be 

 chosen. 



Various studies concerning the deep ocean will be reported, including (a) causes 

 and rates of corrosion and changes in physical properties of metals and alloys, and 

 degradation of nonmetallic materials; (b) physical and chemical parameters of sea 

 water; and (c) biodeterioration of materials. In addition, techniques and equipment 

 for emplacing, relocating, and retrieving STU's will be reported. 



