Sahreiber^ Bentkowsky and Kerr 



classes which have sufficient clearance between the sail 

 and the forward hatch to permit the alignment of the 

 axes of the two vehicles, mating is possible in currents 

 well in excess of one knot. For those submarine classes 

 which do not have sxofficient clearance, mating is limited 

 to about 3/4 of a knot. 



The manned simulation program yielded some important by- 

 product results which impacted on the vehicle design. The most 

 significant ones are as follows; 



a) The splitter plate behind the transfer skirt was originally 

 incorporated to reduce flow separation behind the skirt 

 and nminimize axial drag. Model testing unfortunately did 

 not verify this drag reduction. However, the splitter 

 plate was found in the simulation to provide sufficient 

 roll damping to permit mating without automatic roll 

 stabilization (automatic roll stabilization is, however, 

 provided even in the manual mode). 



b) The shock mitigation system, had originally been designed 

 to dissipate energy only for impact velocities in excess 

 of 0.25 feet per second. Below 0.25 ft/sec, the system 

 acted as a spring. However, because the DSRV is 

 neutrally buoyant, it will bounce off any spring unless the 

 impact energy is absorbed. As a result of observing this 

 phenomenon in the manned simulation study, the shock 

 mitigation system was redesigned to provide damping for 

 all impact velocities. 



c) The relative attitude indicators required to assure angular 

 alignment have not yet been incorporated in the design. 



The results of the Ames tunnel tests have been invaluable in 

 gaining an understanding of the problems involved in submarine 

 mating. In the early phases of the simulation program, before the 

 Ames results were available, mating runs were made under free 

 stream conditions. Although there had been apprehension about the 

 ability of the pilot to perform the 6 degree of freedom control function 

 manually, we found that experienced aircraft pilots, with nominal 

 DSRV simulator training, could control the DSRV with ease. Success- 

 ful mating to currents up to two knots were anticipated for virtually 

 all orientations and in excess of two knots for the most favorable 

 conditions. 



The inclusion of the interaction effects, particularly on the 

 forward hatch, dampened our optimism. The performance goals 

 could be met, but at considerably reduced current magnitudes, and 

 requiring considerably more pilot training. 



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