From: jishnu@nospam.verizon.net   
      
   On 2/15/2016 1:56 PM, Clark F Morris wrote:   
   > On Mon, 15 Feb 2016 12:32:55 -0600, Stephen Sprunk   
   >  wrote:   
   >   
   >> On 15-Feb-16 07:50, Clark F Morris wrote:   
   >>> Charles Ellson  wrote:   
   >>>> kh@pnnnnx.kom (Kurt Hackenberg) wrote:   
   >>>>> Stephen Sprunk   wrote:   
   >>>>>> This is why all new high-speed lines are 2x25kV.   
   >>>>>   
   >>>>> What does 2x mean?   
   >>>>>   
   >>>> https://en.wikipedia.org/wiki/25_kV_AC_railway_electrification -> 2   
   >>>> × 25 kV autotransformer system   
   >>>>   
   >>>> https://www.railelectrica.com/traction-distribution/2x25-kv   
   traction-system/   
   >>>   
   >>> Can as much power be transmitted from the grid to the locomotives /   
   >>> EMUs at 12.5 KV as is delivered at 25 KV at a given frequency?   
   >>   
   >> As written, yes, but it requires twice the current, which means even   
   >> more power pulled from the grid but lost to resistance rather than   
   >> delivered to the trains.  That's not good.   
   >>   
   >> If you actually meant 2x12.5kV and/or 2x25kV, that ratio may change.   
   >   
   > The reason I am pursuing this is that the latest M8 Metro-North EMUs   
   > only work on 60 Hz (and 3rd rail DC).  Thus in order to get them to   
   > Penn Station and beyond the Amtrak line at least from Sunnyside south   
   > and west would have to be converted to 60 Hz, either at 12.5KV or 25   
   > KV in order to use the M8s on NJT.  Given the tight clearances in the   
   > tunnels, 25 KV may be virtually impossible to implement.  Hence the   
   > interest on what the performance implications of changing from 25 Hz   
   > to 60 Hz.  So far as I know, all NJT equipment currently in operation   
   > can run under 12.5 Kv, 25 or 60 Hz and 25 KV 60 Hz as can all Amtrak   
   > equipment.   
   >   
   > Clark Morris   
   >>   
   >> S   
      
   You can pursue it all you want, but that is not happening, since Amtrak   
   is installing more static converters at their Sunnyside feed.   
      
   An easier solution to the problem is what Metro North is actually doing,   
   which involves extending third rail from Harold to Gate interlocking   
   where 60Hz ends and 25Hz begins and have the MNRR EMUs operate into Penn   
   Station using third rail.   
      
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