■«^^ 



Figure 23. Plastic electrical insulation tape wrapped around plastic rods. 



The burlap wrappings (Figure 24) on all the plastic rods and tubes were 

 deteriorated by bacterial action, and the material could easily be torn apart by hand. 

 The rubber electrical tape wrappings were not affected by fouling organisms although 

 there were hydroids and sponges growing on the rubber material. Slight cracks 

 (Figure 25) were found on the rubber and were probably produced by the effects of 

 the deep-sea environment. 



0.015-Inch Insulation on No. 16 Wire . The 15-inch-long nonstressed (straight) 

 wire specimens were lost because the plastic cable clamps which held them to the 

 phenolic laminated sheet were severed;- however, the stressed (coiled) wire specimens 

 were recovered (Figure 26). In the laboratory, the insulations were examined under 

 a stereoscopic microscope for signs of any deterioration. Electrical tests, such as 

 insulation resistance and voltage breakdown tests, were also conducted on these 

 specimens. The results of the electrical tests are presented in Table 10. 



The entire surface area of the silicone rubber insulation was roughened, and 

 the thickness of the insulation was reduced considerably by the nibbling and chewing 

 action of some marine organisms (Figure 27). The surfaces of other insulations, such 

 as polyvinyl chloride, polyethylene. Government rubber styrene (GR-S), and neoprene 

 rubber, were not affected. However, there were deep cracks in one area of a neo- 

 prene rubber insulation (Figure 28), exposing the conductor to seawater. The insulation 

 was exposed about 3 feet above the sediment. 



31 



