b. With two guidelines: The guidelines will be used to 

 restrict the path of the load and improve the accuracy 

 of the landing of the load. Possible use includes the 

 assembling of prefabricated parts of a structure. The 

 experiment will also evaluate the possibility of line 

 entanglement for a multiline load handling system. 

 Various types of embedded anchors may be included in 

 the experiment for evaluation. 



2. Buoyancy Control Systems for Near Bottom Operations . 



Collapsible pontoons (8 tons or 25 tons capacity) may be 

 used as subsurface short-range lifting and lowering devices. 

 The air supply will be provided by a surface vessel. The 

 purpose of the experiment would be to study the feasibility 

 of using a buoyancy controlled system for local lifting 

 chores. To facilitate control, moorings may be employed. 



III. Structural Subsystems (WBS 2.1500) 



A. Pressure-Resistant Structures (WBS 3.1510). The objectives 

 of these experiments are: to evaluate the technology for the 

 modular construction of permanent-type, one-atmosphere struc- 

 tures on the ocean floor; to study the long-term effects of 

 the ocean environment on concrete structures, and to evaluate 

 window and connector hardware components and techniques for 

 installing them. A one-atmosphere concrete structural system 

 will be assembled and will consist of one or more 5- to 10-foot 

 diameter concrete cylinders. The cylinders will be about 20 

 feet long and will be capped at each end with concrete hemis- 

 pheres. Each of the one-atmosphere hulls will be lowered to 

 the ocean bottom with a dry one -atmosphere interior. Parti- 

 cular experimental areas are described below: 



1. Concrete Cylinders and Spheres . The one -atmosphere con- 

 crete structural system will be left in place after com- 

 pletion of the construction phase in order to study certain 

 long-term effects of the ocean environment on the integrity 

 of concrete structures. 



a. Moisture Penetration: The long-time effectiveness of 

 various waterproofing techniques will be evaluated. 



b. Creep Experiments: Deformations in the structures 

 will be monitored periodically to determine whether 

 significant changes take place. 



c. Deterioration Experiments: The condition of the con- 

 crete will be examined periodically from a submersible 

 or a tethered vehicle. 



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