It is speculated that the primary limitation factor in utilizing this 

 technique at depths greater than 4500 meters would be the increase in line 

 tensions. 



X. Recommendations 



As in any operation of this type, problems were encountered and lessons 

 were learned. Although the recovery technique described in this report worked 

 exceptionally well, the following recommendations for improving or simplifying 

 the operation are provided. 



It is recommended that release of the sweepline from the "Bruce" anchor 

 take place as soon as it is clear that the sweepline is in contact with the 

 mooring line. 



An improvement in the cutting action of the sweepline could be 

 achieved by using a mine sweeping cable equipped with cable cutters or line 

 chippers. Grapnels should be attached to the lower end as a back up. 



Severe weather conditions at the time would have made retrieval of the 

 sentinel weight yery dangerous. Consequently, after removal of the sentinel 

 pinger and transponder, the sweepline array was cut away. The result was 

 the loss of the sentinel, grapnels, depressor weight, 600 meters of cable 

 and the bottom anchor release. To reduce the possibility of such a loss, it 

 is recommended that the sentinel transponder (anchor release) be installed 

 between the sentinel and the array so that the sentinel can be jettisoned 

 if necessary. 



Electronic equipment problems were limited to the bottom finding 

 pinger. Failures were traced to cold solder joints and faulty batteries 

 resulting in power loss at low temperature. Modifying the pinger to have an 

 on-off duty cycle proved to be unnecessary as interference with the acoustic 

 transponders was not observed. 



A major improvement in the conduct of the operation would be the use 

 of a computer/plotter to ease the burden of manual data reduction and plotting. 



16 



