Forced descent and ascent can be accomplished by using the tension 

 in a wire rope to pull the positively buoyant plant down. Tension may be 

 induced by a winch in the plant or on the surface of the plant. The effective 

 drum diameter will increase as the plant descends which, with constant 

 torque applied, will cause the plant to slow down with depth. The analysis 

 begins with the plant on the surface and rigged for forced descent by the 

 winch-down method. The winch and rope must be contained below the 

 plant's center of gravity. Reserve buoyancy tanks and stabilizers were not 

 included in this analysis. The rope would be level-wound on the drum and 

 monitored for constant tension. Loss of tension would indicate that the 

 plant is sinking, which requires dropping emergency ballast for more positive 

 buoyancy. As the plant descends, it experiences the same buoyancy 

 variations as the free descending plant. A bottom-sensing device would 

 provide a signal to decelerate the winch for bottoming. A certain amount of 

 tension must always be maintained in the winch rope during and after 

 deceleration. Temperature variations would also affect this method of 

 deployment. The plant would surface by reversing the winch operation. The 

 advantage of the forced descent method is that it allows the plant to be 

 positioned on the desired site. A free ascent must be provided for emergencies. 

 Should a winch failure occur, the winch, drum, and cable would be jettisoned 

 to remove the anchor restraint. If the load module becomes flooded and the 

 power module is not flooded, the load module could be jettisoned. 



In a guided descent the in-situ plant slides down a vertical guide rope 

 in a ballasted descent. The rope would be anchored at the desired bottom 

 location. A hanging weight slows the descending station by actuating a brake 

 on the guide rope. The plant surfaces by dropping ballast in a free ascent. 

 The magnitude and rate at the brake is applied when bottoming is critical 

 because the rope could break. For this reason, the guided descent was not 

 given further consideration. 



In-Situ Plant Hardware. Base legs for the in-situ plant would provide 

 stabilizing surfaces during descent and ascent, a broad base when the plant is 

 on the bottom, large bearing areas for soft bottoms, and a means for plant 

 leveling. The legs could also be used to house TV cameras and lighting. Each 

 leg would consist of a stiffened A-frame made from light pipe sections hinged 

 to the plant base. Brakes would be fitted to drums mounted on the hinge pin 

 to control the leg attitude and to absorb moments resulting from leg reactions. 

 Leg rotation (down) is accomplished by releasing the brakes. Although the 

 operation does not require it, the legs could be elevated by using a motor- 

 driven worm gear in each hinge. Large pads could be fitted at the end of each 

 leg. The pads would consist of a snow-shoe base to provide support in soft 

 bottoms. The entire pad is connected to the leg end by a pin, permitting it to 



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