INTRODUCTION 



In March 1962 as part of a research program to determine the effects of the 

 deep ocean environment on various materials, the U. S. Naval Civil Engineering 

 Laboratory (NCEL) placed the first of a series of Submersible Test Units, designated 

 STU 1-1, on the ocean floor in 5,300 feet of water at Test Site I off the coast of 

 California (Figure 1). Since then additional STU's have been placed on the sea 

 floor and these are listed in Table 1 with pertinent information about each STU. 



STU 1-2 was recovered in October 1965 after 24 months on the sea floor in 

 5,640 feet of water. A sketch of the STU 1-2 system as installed is shown in 

 Figure 2. The STU was loaded with 1,521 specimens of 429 materials. The majority 

 of these materials were metal and metal alloys for the study of corrosion. For bio- 

 deterioration study, nonmetal lie materials, such as woods, ropes, plastics, glass, 

 and elastomers, were assembled in two aluminum racks (bio-racks) and then attached 

 to the side of the STU for exposure in the deep ocean. 



This report presents the materials and the methods used for attracting, collecting, 

 and evaluating deep ocean fouling and boring organisms and the results of field and 

 laboratory investigations of materials recovered from STU 1-2. 



RESEARCH METHODS 



Oceanographic and Biological Information 



Concurrently with the STU program, numerous oceanographic and biological 

 data-collecting cruises to the STU sites have been conducted. These have produced 

 information about the environmental parameters, such as salinity, temperature, 

 oxygen content, and biological activity. Such information is essential in evaluating 

 changes in the materials exposed on the ocean floor, especially the corrosion of 

 metals. The environment for Test Site I (5,640-foot depth) is presented in Table 2. 



Test Site I was selected because the area provides a nominal 6,000-foot depth 

 reasonably representative of the open sea conditions in the eastern part of the Pacific 

 Ocean. It is located approximately 80 nautical miles southwest of Port Hueneme, 

 California. 



