Performance/Failure Analysis of Acoustic Array Connectors and Cables After 6-10 Years of Service

A performance/failure analysis was conducted on three acoustic arrays recovered from a depth of 3300 ft at a naval tracking range off St. Croix in the Virgin Islands. The analysis included bench tests of electronic components and examination of connectors, cables, seals, and housings with electron microscopes, X-ray diffraction, and optical microscopes to determine the effectiveness of design features and materials. One array had been submerged for about 10 years, the others for 6 years. Cables with polyethylene jackets performed satisfactorily whereas cables with polyurethane jackets exhibited leaks and visible circumferential cracks approximately 1/4 in. long. Of 42 double O-rings examined, 8 of the first O-rings leaked; half of these were on one array. The second O-ring on all seals was effective. Arcing, apparently due to lightning, produced a low resistance in one of the Morrison connector seals by creating a carbon path of charred teflon. Certain packing seal glands and backup washers in the Morrison seals of one array sustained permanent deformation because of improper assembly.