INTRODUCTION 



Recent interest in, and emphasis on the deep ocean as an operat- 

 ing environment has created a need for information about the behavior 

 of constructional materials in this environment. 



The Naval Facilities Engineering Command of the Office of Naval 

 Materiel is charged with the responsibility for the construction of 

 all fixed Naval facilities, including the construction and maintenance 

 of Naval structures at depths in the oceans. 



Fundamental to the design, construction and operation of structures 

 and their related facilities, is information about the deterioration 

 of materials in the deep ocean environments. This report is devoted 

 to the effects of these environments on the corrosion of metals and 

 alloys , 



A test site was considered to be suitable if the circulation, 

 sedimentation, and bottom conditions were representative of open ocean 

 conditions: (1) the bottom should be reasonably flat, (2) the site 

 should be open and not located in an area of restricted circulation 

 such as a silled basin, (3) the site should be reasonably close to 

 Port Hueneme for ship operations, and (4) the site should be within the 

 operating range of the more precise navigation techniques. 



A site meeting these requirements was selected at a nominal depth 

 of 6,000 feet. The location of this site in the Pacific Ocean in 

 relation to Port Hueneme and the Channel Islands is shown in Figure 1 

 as Submersible Test Units (STUs) I-i, 1-2, 1-3, and 1-4. 



The environmental conditions at the bottom, a depth of 5,650 feet 

 at a location about 5 miles northwest of STU I-l were reported to be 

 as folloxjs;-^ 



1. Temperature 2.53°C 



2. Salinity 34.58 ppt 



3. Oxygen 1.29 ml/1 



The complete oceanographic data for Site I are shown graphically 

 in Figure 2.2,3 ^ portion of this data collected from 1961 to 1963 

 showed the presence of a minimum oxygen zone (as shown in Figure 2) 

 at depths between 2,000 and 3,000 feet. Oceanographic data obtained 

 at other Pacific Ocean sites also showed the presence of this minimum 

 oxygen zone regardless of depth to the ocean floor. 



Corrosion rates are affected by the concentration of oxygen in 

 the environment. Therefore, it was decided to establish a second 



