INTRODUCTION 



The development of deep diving vehicles which can stay submerged 

 for long periods of time has focused attention on the deep ocean as an 

 operating environment. This has created a need for information con- 

 cerning the behavior of common materials of construction as well as 

 newly developed materials with promising potentials, at depths in the 

 ocean. 



To study the problems of construction in the deep ocean, project 

 "Deep Ocean Studies" was established. Fundamental to the design, 

 construction and operation of structures, and their related facilities 

 is information with regard to the deterioration of materials in deep 

 ocean environments. This report is devoted to the portion of the pro- 

 ject concerned with determining the effects of these environments on 

 the corrosion of metals and alloys. 



The test sites for the deep ocean exposures are shown in Figure 1 

 and their specific geographical locations are given in Table 1. The 

 complete oceanographic data at these sites, obtained from NCEL cruises 

 between 1961 and 1967, are summarized in Figure 2, Initially, it was 

 decided to utilize the site at the 6,000 foot depth. Because of the 

 minimum oxygen concentration zone found between the 2,000 and 3,000 

 foot depths, during the early oceanographic cruises, it was decided to 

 establish a second exposure site (STU II- 1 and II-2) at a nominal 

 depth of 2,500 feet. For comparative purposes, the surface water site 

 V was established. Even though the actual depths are shown in the 

 tables, the nominal depths of 6,000 and 2,500 feet are used throughout 

 the text. 



A summary of the characteristics of the bottom waters 10 feet above 

 the bottom sediments at the two deep ocean exposure sites and at the 

 surface exposure site is given in Table 1, 



Sources of information pertaining to the biological characteristics 

 of the bottom sediments, biological deterioration of materials, detail- 

 ed oceanographic data, and construction, emplacement and retrieval of 

 STU structures are given in Reference 1. 



The procedures for the preparation of the specimens for exposure 

 and for evaluating them after exposure are described in Reference 2. 



Previous reports pertaining to the "performance of materials in 

 the deep ocean environments are given in References 1 through 8. 



This report is a discussion of the results obtained of the 

 corrosion of copper and copper alloys for the seven exposure periods 

 shown in Table 1. 



RESULTS AND DISCUSSIONS 



The results presented and discussed herein also include the 

 corrosion data for copper alloys exposed on the STU structures for the 



