3.1.2 DEPLOYMENT TECHNIQUES 



Deployment of the cable is accomplished by a center puUout technique from a pre- 

 wound stationary spool. The pullout deployment concept requires that the cable unwind 

 from the ID of the spool. To avoid snagging and breakage in the payout guideway, it is 

 imperative that the cable free itself from the binding agent/cable matrix that makes up the 

 spool in a highly uniform manner. One key to achieving this uniform payout is the selection 

 of an inside payout technique, in which the cable breaks free from the inner wall of the 

 spool and has an unobstmcted path to the payout tube. 



3.1.3 SPOOL FABRICATION CONSIDERATIONS 



A prototype, manually operated, fiber-optic winding machine was developed and 

 used to wind a number of trial spools for prehminary feasibility tests during FY 78. Several 

 100-meter lengths of unarmored, plastic-buffered optical fiber elements, proof-tested at a 

 400-kpsi level, were wound with a pretwist so that upon deployment the fiber would not 

 kink. An adhesive was manually applied to provide a binding force such that pullout re- 

 quired about 1/10 lb. Several binding agents were qualitatively evaluated, including waxes, 

 aerosol rubber cements, and lacquer. A deployment experiment was conducted in an under- 

 water test tank where the fiber was deployed at rates up to 18 knots without breakage. 



These initial tests demonstrated the feasibility of the deployment concept, but left 

 open the questions of which tether design and which binding agent need to be used in an 

 actual application and also underscored the length-versus-strength tradeoffs which become 

 critical concerns with long fibers because of their impact on mission costs. The prehminary 

 fabrication/deployment work showed that it is possible to use this approach in the laboratory. 

 However, the initial work also showed that it takes 3 to 4 hours of a technician's time 

 manually to wind 100 meters uniformly. Thus the winding process was subsequently auto- 

 mated and expedited to make the spool/package inexpensive. It became obvious after some 

 experience that extreme flexibility in altering the winding parameters would be necessary in 

 follow-on efforts if pertinent questions were to be addressed and solutions found. 



To fabricate the spools, a microprocessor-controlled winding machine is now used to 

 position each coil precisely as it is wound on the takeup mandrel (fig 6). Synchronously, as 

 each coil is formed, a 360-degree pretwist is applied. As the cable goes onto the mandrel, 

 the adhesive is applied to fix each coil relative to the other coils in an in-line process. The 

 machine currently is capable of winding 5 km of 35-mil-OD cables. Because the guide head 

 movement or advance is controlled by the microprocessor, any diameter of cable can be 

 wound with a simple change in the control program. The machine is presently capable of 

 winding 1 km of cable in less than 3 hours. Changes to the software and the motor drive 

 units will increase this rate to less than 1 km/hour for a 1 0-km spool. 



The microprocessor-controlled winding machine made spool fabrication practical 

 and at the same time very flexible. For the EAVE WEST submersible, a standard spool ID 

 of 5 inches was chosen because of optical loss considerations. A sample 500-ft deployment 

 spool fabricated automatically by this machine for the EAVE WEST vehicle is shown in 

 figure 7. The deployment canister and standoff stinger used on this submersible are shown in 

 figure 8. 



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