On Sunday, 17 January 2016 05:22:34 UTC+1, Stephen Sprunk  wrote:   
   > On 16-Jan-16 22:01, hancock4@bbs.cpcn.com wrote:   
   > > Stephen Sprunk wrote:   
   > >> Amtrak (and its predecessors) have been doing up to 135mph on 11kV   
   > >> 25Hz lines for around a century; the main reason they couldn't go   
   > >> faster was the variable-tension catenary.  That's roughly twice as   
   > >> much current as 200mph on 2x25kV lines in France and China, so I'm   
   > >> not sure current is really a limiting factor.   
   > >    
   > > I wouldn't say a "century", since the electrification dates to the   
   > > 1930s.   
   >    
   > I said "around a century"; 80+ years is close enough.   
   >    
   > > As to current load, the North Shore's Electroliners, using 600 V   
   > > trolley poles, ran very fast,   
   >    
   > That's 214,000 lbs for 106 seats, or 1.01 ton/seat, and a top speed of   
   > 90mph.   
   >    
   > For reference, Acela is 1,246,000 lbs for 304 seats, or 2.05 ton/seat,   
   > and has a top speed of (now) 160mph, which should requires over six   
   > times as much power.   
      
   A bit more data:   
      
   ICE3 manages about 0.9 tonnnes/seat (yes, ton != tonne but it's close enough),   
   a set is rated for 8 MW (11,000 hp) and runs at 320 km/h (about 200 mph) with   
   a single pantograph under 15 kV @ 16.7 Hz.  Compare that with the Acela which   
   is rated at 4.6 MW (   
   6200 hp) per power car.   
      
   A single ICE3 at maximum power is drawing 533 A (depending on power factor)   
   per set, and they routinely run as double-sets, so 1066 A through 2   
   pantographs.  An Acela hypothetically running at maximum rated power under 11   
   kV would be drawing 418 A (   
   depending on power factor), or 836 A with two pantographs for a one-each-end   
   set.   
      
   The most recent TGV sets are rated at 3.68 MW (4930 hp) across two power cars   
   when running under 1500 V DC.  That corresponds to 2453 A for the train, or   
   1226 A per power car (under DC they run with one pantograph per power car,   
   under AV it's a single    
   pantograph for the train, with a 25 kV bus connecting the two power cars.   
      
   It looks to me like the ICE3 draws more current at a higher speed and lower   
   frequency (16.7 Hz) than a hypothetical Acela running at top speed under 11 kV   
   @ 25 Hz, so I suggest that this is not going to be a limiting factor.   
      
   Robin   
      
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