From: cfmpublic@ns.sympatico.ca   
      
   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-   
   raction-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   
      
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