The weight of ALVIN was carefully considered. Recovery of objects of this size from 

 such a depth had not been accomplished previously. ALVIN, with a weight of 31,500 pounds 

 in air, was estimated to weigh 8,800 pounds in water with the sphere flooded, assuming that 

 the syntactic foam was still fully effective. Syntactic foam is known to suffer water permea- 

 tion during long exposures at elevated pressure. There was neither experience nor data avail- 

 able on the effects of submergence at this depth for such a long period; accordingly, the loss 

 of buoyancy could not be accurately estimated. If the entire syntactic buoyancy of 9,300 

 pounds had been lost, the in-water weight would be increased to 18,100 pounds. Complete 

 loss of buoyancy imparted by the syntactic was not, however, considered probable; the antic- 

 ipated loss was expected to be 30 percent or less. 



An additional factor affecting the lift was bottom breakout. Breakout forces were ex- 

 pected to be as high as 25 percent of the in-water weight of ALVIN. Since these forces are 

 dependent upon the time period over which the force is applied, it was estimated that the 

 breakout force could be reduced to about 10 percent of the in-water weight if a gradual 

 breakout was effected. 



In consideration of the depth and lift weights involved, a single piece of 4 1/2-inch 

 Columbian double-braided nylon line with a nominal length of 7,000 feet and a breaking 

 strength of 53,000 pounds was selected as the primary lift line. Two back-up lift lines 

 would also be provided, one of 4 1/2-inch double-braided Samson nylon and the other of 

 8-inch polypropylene. (A complete listing of the equipment used during the ALVIN sal- 

 vage operations is given in Appendix C.) 



Lift Line Attachments 



Potential methods for attachment of the lift line to ALVIN were evaluated with respect 

 to operational requirements and cost factors. 



Tethered Devices. Three tethered devices were available for consideration; two of these, 

 however, did not meet the depth requirements and would present positioning and maneuvering 

 problems. Conversion and testing of these two devices would require unwarranted expendi- 

 tures of time and money. The third available tethered device, CURV, met the depth require- 

 ments; however, she had one disadvantage in that she could not take the recovery line down 

 to ALVIN, but rather must rely on surface placement in the vicinity of ALVIN. 



Manned Submersibles. Three manned submersibles were considered for this operation, 

 DEEP QUEST, DOWB, and ALUMINAUT. DEEP QUEST was ruled out, as it is mandatory 

 that her support platform, the TRANSQUEST, be used at all times. This would present pro- 

 hibitive transit time and costs from her home port of San Diego to the East Coast. DOWB, 

 used during the 1968 ALVIN salvage operations, was considered too vulnerable during launch 



