RESISTANCE OF MATERIALS TO MARINE BIOLOGICAL ATTACK 1123 



cell is set up with 20 per cent copper sulfate solution as the electrolyte, 

 and a copper plate as the anode. The cathode is a loop of the insulated 

 conductor from the cable. Any plating out of copper on the cathode 

 indicates a break in the insulation. In this way the integrity of a rela- 

 tively long length of conductor can be examined critically and simply. 



One of the outstanding facts apparent from the examination of cable 

 samples has been the evident importance of the outer jute in limiting 

 the corrosion of armor wires. Galvanized steel armor wires which still 

 retain the protection of flooding compounds, such as asphalt, tar or 

 pitch, together with outer servings of impregnated jute, have shown 

 negligible steel corrosion within 40 years, and in one case for as long as 

 66 years. On the other hand, most of the corrosion of armor wires which 

 has been observed has occurred in cable from which a major part, or all, 

 of the outer jute has been lost. 



Table XIV — Locations and Depths from W' high Submarine 



Cable Samples have been Obtained for 



Laboratory Examination 



