designed for a line tension of 5,000 pounds. According to cognizant personnel, 

 the availability of power is the primary limitation on submersible winches at 

 depths as great as 6,000 feet. A bottom-supported winch with a 10,000-pound 

 rated capacity will move a suspended load about 50 feet and about 230 feet 

 for 100-ton and 600-ton loads, respectively, at a depth of 6,000 feet. Sub- 

 mersible winches operable at 6,000 feet are not available as off-the-shelf items, 

 so estimated costs run high. Previous estimates indicate that the cost for a 

 10,000-pound winch to operate at 6,000 feet may exceed $250,000.^-^^ 



The use of underwater winches in the deep ocean requires anchorages 

 to act as reaction points. Some types of anchors suitable for this function 

 include explosive anchors, deadweight anchors, pile anchors, and embedment 

 anchors. The most likely candidates are probably explosive and embedment 

 anchors. 



Underwater winches are likely to require the use of a submersible with 

 controlled appendages to operate the winches. Activation of the winches 

 may be accomplished remotely if sufficient reliability can be built into these 

 systems. Several configurations for the use of underwater winches were 

 suggested by Kusano in an unpublished report.^'' Schematic diagrams of the 

 use of a bottom winch and an auxiliary manned submersible are shown in 

 Figures 1 and 1 1 . Figures 1 2 and 1 3 show concepts in which the winch is 

 mounted on the load. Figure 14 illustrates the use of a winch with a manned 

 bottom crawler vehicle. 



Bottom Crawler 



By employing the tractive force developed by wheels or tracks, a 

 bottom crawler could conceivably displace and position heavy, suspended 

 loads. The vehicle, manned or unmanned, would grasp the load and direct 

 final lowering and positioning. The vehicle would be powerful enough to 

 pull or push the suspended load to the desired alignment position or it could 

 serve as a work monitor, relaying positioning data to the surface based 

 lifting/lowering system. 



As a guidance and positioning subsystem, however, the bottom 

 crawler concept has some serious limitations. First, is its dependence on 

 bottom soil properties. Except where sandy, rocky, or firm soil abound, 

 these vehicles will be prone to sinking-in and becoming hopelessly mired in 

 bottom sediments. Where soils have sufficient strength to allow operation of 

 crawlers, stirred-up bottom sediments are likely to obscure visibility. 



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