This report is a description of the inspection and evaluation of 

 the replacement array, the AUTEC array after retrieval, an outline of 

 the results of the inspections and evaluations, and a discussion of the 

 application and revision of the inspection guidelines. 



ARRAY RECOVERY DESCRIPTION 



As shown in Figure 1, the AUTEC acoustic array emp laced in 1962, 

 consists of two main parts: the deep water mooring and the acoustic 

 string. The system was so designed that the acoustic string could be 

 retrieved and replaced without retrieving the deep water mooring. In 

 December 1973 the upper buoy was found washed ashore. The 21 -quad cable 

 used in the acoustic string had parted at or near the cable termination 

 on the second termination below the main buoy. It was determined during 

 an inspection of the failed array using a manned submersible that the 

 acoustic string had fallen on the main mooring buoy. It was then planned 

 to retrieve the acoustic string by attaching to the bitter end of the 

 failed 21 -quad cable, raising the bitter end to the surface, and then 

 retrieving the acoustic string in a normal manner. It was planned to 

 replace the failed acoustic string with a new unit if the condition of 

 the deep water mooring, as inferred from the condition of the failed 

 acoustic string, could be expected to have a reasonable additional 

 service life. 



During 11 days of at- sea operation 1,200 feet of electromechanical 

 (21 -quad) cable, nine hydrophones, two acoustic beacons, an underwater 

 communications transducer (UQC) and the tracking arm assembly were 

 retrieved by the primary recovery vessel, the R. V. Hunt. As deck space 

 on the E. V. Hunt was limited, the cable, hydrophones, beacons, and UQC 

 were transferred to an auxiliary recovery vessel, the J. W. Pierce^ for 

 inspection. The tracking arm assembly was too large to safely transfer 

 at sea, and it was inspected on the B. V. Hunt. 



FIELD INSPECTION 



The field inspection, following the guidelines included as Appendix 

 A to this report, was made by an experienced corrosion engineer of the 

 Navy's Civil Engineering Laboratory. A professional photographer from 

 Lockheed Electronics Co. , together with an assistant, was responsible 

 for the retrieval and inspection photography. Technical assistance for 

 the inspection was furnished by personnel from the Naval Underwater 

 Systems Center, and the Naval Ship Research and Development Center. 

 Mechanical assistance was furnished by the crew of the recovery vessels 

 belonging to Traaor MAS. All inspection equipment and supplies as 

 outlined in Appendix A, except for the crating materials, were available 

 on site. 



