Electromechanical (21 -Quad) Cable 



The cable had parted at the upper end of the second breakout housing 

 below the upper buoy. The failed end of the cable showed significant 

 corrosion of most of the outer and inner armor wires. The attack was 

 localized at the areas of the wire where the polyethylene jacketing on 

 the individual wires had been removed in assembling the terminations. 

 The galvanized coating on the wires was intact under the polyethylene ■ 

 jacketing but was not present on most of the wires adjacent to the point 

 of failure. 



The only significant corrosion of the entire 1 ,200-f oot-long section 

 of electromechanical cable retrieved was at the cable terminations. 

 This attack was localized adjacent to and just Inside the outer edge of 

 the wire-retaining slots in the termination. At these areas the protective 

 polyethylene jacket had been removed from the wires in order to assemble 

 the termination. The corrosion preventive compound used to fill the 

 interior of the termination housings was, in most cases, not present in 

 this critical area. There was a general trend for the presence of more 

 of this corrosion preventive compound in those housings exposed at a 

 greater depth on the array. In order to quantitatively evaluate the 

 condition of the electromechanical cable at the terminations thirteen 

 terminations were disassembled for inspection. The minimum diameter of 

 each wire was measured. The data from these measurements was analyzed 

 by NUSC in an attempt to predict the remaining life of the unrecovered 

 cable at the terminations. The only trend noted in a field evaluation 

 of this data was that the wires, particularly the inner armor wires, 

 were less corroded in those terminations which had retained a large 

 amount of corrosion preventive compound than in those terminations which 

 had retained little corrosion preventive compound. As noted above, ' 

 retention of this compound was generally, but not reliably, a function 

 of depth. It was noted during these inspections that approximately 50% 

 of the wires were not properly seated in the termination block. Eleven 

 terminations and a 25- foot section of cable were retained by NUSC and 

 NSRDC for further analysis. 



Cable Termination Housings 



The steel termination housings were in good to fair condition. The 

 most severe attack was on the end sleeves. However, penetration of 

 these end sleeves (1/8-inch original thickness) was noted in only two 

 cases. A thin, patchy deposit of copper was noted on the surfaces of/ 

 miany of the housings. This was most probably due to substitution of 

 electrogalvanizing for hot-dip galvanizing on the housings. Electro- 

 galvanizing generally employs a thin copper plating, or flash, over the 

 steel to promote good adhesion of the electrodeposited zinc coating. 

 This copper deposit can, and probably did, lead to galvanic attack of 

 the portions of the housing which did not originally have, or did not 

 retain, the copper deposit. As no copper deposits were found on the end 



