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   
   >    
   > Large ships make their money by moving goods as quickly and cheaply as    
   > possible.  Turnaround time in port is often less than 48 hours,    
   > sometimes less than 24.    
      
   A lot of short routes are dedicated with cargoes that require a lot of   
   handling on the loading and discharge, i.e., banana boats from Columbia to   
   Florida.   
      
   Owners don't like it but it's very common for the crew slow the loading, i.e.,   
   throttle back at the manifold on tankers, to spend more time at the mall.  The   
   dock rats are complicit for the easy overtime pay so the port captain is   
   always pissed off at a    
   lot of strangers.   
      
   > That means to partially recharge the batteries    
   > they will need around a 1GW supplied every hour (based on your 57.6    
   > GW-hrs figure). You're going to need quite a few power stations to be    
   > able to supply that amount of energy on top of normal consumption (plus    
   > that for all the proposed electric cars which will be around?).   
      
   They'll need another big Na-S battery at the dock.   
      
      
   Bret Cahill   
      
      
   "They aren't making any money sitting on Rio de la Plata."   
      
   -- Port Captain   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)