A Conductor Test to Determine Biological Deterioration of Organic Coatings 

 and Insulations. Various organic coatings and Insulations for wire conductors designed 

 for use In shallow and deep water will be evaluated for biological deterioration. 

 Hydrostatic pressures (up to 15,000 psi) will be applied in a high-pressure test vessel 

 to organic Insulating materials coated on a wire conductor and to commercially 

 available insulated wire conductors. Coils of pressure-applied and nonpressure- 

 applied test materials will be placed in separate covered glass jars containing sea 

 water and marine sediments, and results will be compared and evaluated. This 

 medium will also contain species of viable microorganisms normally found in sea 

 water and bottom sediments. Insulation resistance measurements will be taken 

 periodically to indicate any changes in dielectric strength. Microscopic examinations 

 of the Insulations will be performed when electrical failure has occurred, and It will 

 be determined If breakdown of wire coatings occurred In the sediment or in the water. 

 Conductors will be placed In sterile sea water and sediments to serve as controls. 

 It Is believed that valuable and readily applicable engineering data can be obtained 

 by using this test technique. 



Studies on Deterioration of Metals by Marine Microorganisms . This investigation 

 will consist of basic research on the effects of marine microorganisms on the corrosion 

 of various metals. Because bacteria are capable of Inhabiting varied marine environments 

 and are able to utilize various organic and inorganic materials from the sea for growth, 

 it is expected that marine bacteria (Including the sul fate-reducers) would be one of 

 the major biological agents of deterioration of various engineering materials in sea 

 water and in marine sediments. 



The marine anaerobic sulfate-reducing bacteria which reduce sulfates and 

 sulfites to hydrogen sulfide during their metabolic process have assumed particular 

 significance since It was discovered that they are agents of severe deterioration of 

 Iron and steel in the sea. It is felt that any Information obtained from this study on 

 the mechanism of corrosion of metal due to bacterial action or Its metabolic by-products 

 will aid researchers in developing methods of prevention and control of deterioration 

 of various organic and inorganic materials for use in the sea environment. 



CONCLUSIONS 



1. Extensive field and laboratory studies have been performed and considerable 

 published Information exists about the deteriorating effects of marine wood-boring 

 animals upon wooden structures in shallow protected waters. However, there have 

 been very few controlled field or laboratory studies made about the biological 

 deterioration of materials other than wood in either the shallow or the deep-ocean 

 environments. Thus there is virtually no published data on the behavior of materials 



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