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 in deep 

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



A Submersible Test Unit (STU) was designed on which many test specimens 

 can be mounted. 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 as great 

 as 18,000 feet. This report deals with STU 1-2, in place for 24 months at a depth 

 of 5,640 feet. The test site is about 80 nautical miles southwest of Port Hueneme, 

 California. 



