From: bretcahill@aol.com   
      
   Knowing ship owners are the cheapest folk on the planet, it's 100% certain   
   similar calculation have been done before:   
      
   Vessel displacement:   1,000 kilo ton  (~300 m LOA)   
      
   Prop power:  80 MW   
      
   Na-S battery density:  0.150 MW-hr/ton   
      
   Voyage time:   720 hours   
      
   57,600 MW-hrs   
      
   80 X 720 / 0.150 = 384 kilotons ~ 38% of the weight of the loaded ship   
      
   The ship loses about a quarter of it's cargo capacity but can eliminate most   
   or all of the double bottom tank volume.   
      
      
   Bret Cahill   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)