Railroad Forums 

  • (Tech) Single EMU design for all NYC-area lines?

  • General discussion of passenger rail systems not otherwise covered in the specific forums in this category, including high speed rail.
General discussion of passenger rail systems not otherwise covered in the specific forums in this category, including high speed rail.

Moderators: mtuandrew, gprimr1

 #1192596  by amm in ny
 
mtuandrew wrote:In addition, the original poster posited that Amtrak would also use such equipment.
As the OP in question, I actually hadn't thought about it either way. I mentioned the NEC mainly because AFAIK the NEC uses a different voltage and frequency from some of the other NJ transit lines (IIRC, the line through Summit is 25 kV 60hz.) AMTRAK seems to prefer locomotive-hauled trains over EMUs, anyway, for reasons that have been explored elsewhere (and so don't need rehashing here.)

I'm still unclear about exactly what the problem is with having both high acceleration and high top speed. Is it:
a. Not technically feasable, or
b. Feasable, but (significantly) more expensive than having just one or the other?
 #1192600  by mtuandrew
 
amm in ny wrote:
mtuandrew wrote:In addition, the original poster posited that Amtrak would also use such equipment.
As the OP in question, I actually hadn't thought about it either way. I mentioned the NEC mainly because AFAIK the NEC uses a different voltage and frequency from some of the other NJ transit lines (IIRC, the line through Summit is 25 kV 60hz.) AMTRAK seems to prefer locomotive-hauled trains over EMUs, anyway, for reasons that have been explored elsewhere (and so don't need rehashing here.)

I'm still unclear about exactly what the problem is with having both high acceleration and high top speed. Is it:
a. Not technically feasable, or
b. Feasable, but (significantly) more expensive than having just one or the other?
Ah, sorry for the misunderstanding.

As for high acceleration and high speed, it is technically doable. Problem is, the motors have to be geared really high to avoid the windings falling apart at high speed. That means they can't move the car from a standstill without using a lot more current, and therefore need a much higher horsepower rating to maintain the same acceleration (or tractive effort) as a trainset with a slower overall speed.