service module 

 (power pack 

 and winch) 



(a) Resting on deck. 



lifting slings 

 attached to net 



service module 

 (power pack 

 and winch) 



(b) Being lifted off the deck. 



Figure 5. Net restraint concept for 



attaching the acrylic plastic 

 capsule to the NEMO service 

 module. 



in the presence of structural 

 members serving as the attach- 

 ment, (5) the attachment was to 

 work equally well regardless of 

 whether the capsule was on deck, 

 being lifted, floating on the ocean 

 surface, or being winched down 

 to operational depth, and (6) the 

 attachment subsystem was not to 

 generate excessive tensile stresses 

 in the acrylic plastic capsule that 

 could lead to a failure of a bonded 

 adhesive joint whose minimum 

 strength is approximately 40% less 

 than of the parent material in ten- 

 sion. 



Several design approaches 

 were tried to arrive at a satisfactory 

 attachment between the acrylic 

 plastic sphere and the remainder of 

 the NEMO structure. The most 

 obvious solution to the problem, 

 the placement of the capsule in a 

 net (Figure 5), similar to the nets 

 used for hanging gondolas under 

 spherical balloons, had been 

 immediately discarded as it did 

 not satisfy three of the design 

 constraints. Such a net would 

 considerably restrict the pan- 

 oramic visibility, it would permit 

 excessive relative motion between 

 the sphere and the remainder of 

 the NEMO structure thus impos- 

 ing severe stresses on hydraulic 

 and mechanical control linkages 

 between the control console 

 inside the capsule and the opera- 

 tional components, and it would 

 not provide any support for the 

 capsule when it was being trans- 

 ported on land, or resting on deck 

 of the ship. 



15 



