Diesels on Metro-North

[MARC Rider]

On my ride up to Albany yesterday, we passed a couple of Metro-North Poughkeepsie trains being pushed by dual-mode diesel/electric power south towards Grand Central Terminal. We were south of Croton-Harmon in both cases, and what was interesting was that as we passed the train, it was obvious that the locomotives were running on their diesel engines. Now I know that the locomotives run on third rail power into Grand Central Terminal, but the third rail runs all the way to Croton-Harmon, and I was surprised that they weren't using it. I would have thought at the very least that the MPO for the New York Metro area might want to encourage all-electric running when possible in order to scarf up some emissions credits under the Clean Air Act for the region. Is there some reason that Metro-North would want to run their diesel engines on their dual-modes when electric is available? It can't be like MARC running diesels on the Penn :Line because Amtrac charges them too much for electricity, presumably, this is Metro-North electricity anyway.

 

[railiner]

On my ride up to Albany yesterday, we passed a couple of Metro-North Poughkeepsie trains being pushed by dual-mode diesel/electric power south towards Grand Central Terminal. We were south of Croton-Harmon in both cases, and what was interesting was that as we passed the train, it was obvious that the locomotives were running on their diesel engines. Now I know that the locomotives run on third rail power into Grand Central Terminal, but the third rail runs all the way to Croton-Harmon, and I was surprised that they weren't using it. I would have thought at the very least that the MPO for the New York Metro area might want to encourage all-electric running when possible in order to scarf up some emissions credits under the Clean Air Act for the region. Is there some reason that Metro-North would want to run their diesel engines on their dual-modes when electric is available? It can't be like MARC running diesels on the Penn :Line because Amtrac charges them too much for electricity, presumably, this is Metro-North electricity anyway.

Could it be that the dual mode loco’s run better using diesel’s than on third rail power?

 

[jis]

Could it be that the dual mode loco’s run better using diesel’s than on third rail power?

P32ACDMs have very low max speed in E mode. That is why they are operated in D mode where E mode is not required.

 

[Dutchrailnut]

The max speed in E mode is 60 mph not only because of Locomotive but also time table restrictions.
in E mode there is no dynamic blended brake, (the inverter is used to step up the third rail voltage to 1400 volt DC) so a max timetable speed is 60 mph.
to run in E mode north of MO jct permission must be requested from Rail traffic control.
third rail has many gaps and prolonged running in E mode would drop the HEP and require all those HVAC units on cars to restart every few minutes.
on the New Chargers this should be solved with a battery pack that keeps the HEP functioning for short time to pass those gaps. same battery pack will be used for gap protection in GCT to move train at very low speed during loss of contact.