Railroad Forums 

  • EMD to build North American passenger locomotives once again

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

 #1442620  by mtuandrew
 
NorthWest wrote:Since the passenger operators are fine with urea after treatment, they could still use the 710. Just don't expect it to get over 110 MPH or so.
Why's that? Seems like an F70PACe could reasonably cruise at 125 with a 4400hp 16-710 and separate HEP.

Dutch: oh. Never mind then :P
 #1442651  by mtuandrew
 
NorthWest wrote:Weight. That's largely why they've gone with high speed diesels in the latest generations of motive power.
Thanks. I realized it was kind of a dumb question after I posted it, akin to "why are most new cars built with 2.0L four-cylinder engines (or the equivalent) instead of 360ci V-8s?"
 #1442707  by Allen Hazen
 
At the risk of sounding like a broken record…
Weight is a problem, and many recent U.S. passenger locomotives have been very heavy for 4-axle locomotives. But there are two distinct issues to consider. Reducing over-all weight probably makes things a bit more energy-efficient (less mass to accelerate), but for safe operation at high speeds without damaging the track with "hammer blow," weight per-axle is, I would guess, just as important. So, given that American railroad operators seem to be very cautious and conservative when it comes to choosing engines, and given that they like the tried-and-true, comparatively low-maintenance, but heavy, engine designs from EMD and GE… WHY HAVEN'T WE SEEN A REVIVAL OF THE A1A TRUCK FOR PASSENGER POWER?
 #1483887  by Fan Railer
 
Several things; decreased adhesion, additional wear on curved trackage, likely decrease in maximum allowable speed. If fitted with self steering ability and rider axle height adjustment for increased starting adhesion, cost effectiveness is then questionable. Ultimately, it comes down to the money.