and recovery, even considering the use of support platforms with special handling systems. 

 Also, DOWB's optical viewing system had encountered difficulties during past operations of 

 this nature. 



The third submersible considered for use as the recovery device, and the one finally 

 selected, was the DRV ALUMINAUT, owned by Reynolds Submarine Service Corporation, 

 Miami, Florida. She had the capability of performing the entire operation essentially as a 

 self-contained unit, being capable of carrying the recovery line to the bottom and attaching 

 the line with her two manipulators. In addition, she was available for immediate operations. 



Command and Support Ships 



Command Ship. MIZAR offered unique advantages for a command and lift ship for 

 ALVIN. She was equipped with computerized facilities for accurate navigating and tracking 

 from prepositioned transponders. Her large, stable platform could accommodate a 50,000- 

 pound-pull traction winch, and she could handle a large lift line. The ship could provide tie- 

 down points for additional safety harnesses, nets, and straps placed on ALVIN once she had 

 been raised to near the surface. Additionally, the ship could lift either over-the-side or through 

 its center well. 



Support Ship. The offshore supply boat M/V STAGEY TIDE was selected as the support 

 ship to tend ALUMINAUT, to track her position underwater, and to maintain position rela- 

 tive to a bottom transponder /pinger, which marked ALVIN's position. 



Lift Line Stress Considerations 



- Dynamic response and stress calculations (detailed in Appendix D) indicated that lifting 

 over the U-frame on the starboard side of MIZAR, as was initially proposed, would result in 

 lift line stresses exceeding breaking strength, particularly at very short line lengths. The anal- 

 yses, performed by the Naval Research Laboratory (NRL) and NAVSEC, revealed that lifting 

 through the center well would eliminate the effects of ship roll and pitch, which would reduce 

 lift line resonances to well below the critical point. 



SALVAGE PLANS 



After careful consideration of the aforementioned factors, the decision was made to con- 

 duct the recovery of ALVIN during August 1969. 



On 6 August 1969, the Chief of Naval Research tasked SUPSALV with the responsibility 

 for the recovery of ALVIN. Lieutenant Commander William I. Milwee, Jr., USN, from 



