Discussion relating to the operations of MTA MetroNorth Railroad including west of Hudson operations and discussion of CtDOT sponsored rail operations such as Shore Line East and the Springfield to New Haven Hartford Line

Moderators: GirlOnTheTrain, nomis, FL9AC, Jeff Smith

  by BenH
I've noticed (on weekday mornings between 8:00 and 8:14 when I am on the platform at 125th street) that most, but not all, MN diesel-electric locomotives operate in diesel mode while passing through 125th Street station enroute to GCT.

Why is this? I would have thought that the engineer would have cutover to electric operation before reaching 125th Street station.

Is it (maybe) that the engineer gets more acceleration out of the locomotive when he's in diesel mode?

Is it up to the engineer to decide when and where to switch between electric and diesel operation? What does the MN rule book say about this, if anything.

I'm just curious -- since it would seem to me that it would be less expensive, in today's world of high fuel prices, to have all diesel-electric locomotives operating in electric mode whenever and wherever possible.

  by DutchRailnut
Acceleration in Electric is much faster, the rule is electrc mode must be tried before MO jct. Even when entering tunnel and GCT the diesel stays on however even if it runs in electric.
I personaly switch on the Bridge and let it switch over, then from 125th to GCT I run in Electric and shut diesel down once cab car passes the north end acces stairways.

  by Stephen B. Carey
About switching over to electric, I was wondering, is that done by just flipping a switch in the cab? Or do you have to turn on the 3rd rail shoe, then turn off the engine? I can see that you have some control over the engines operation but isnt it tough to shut down a diesel like that and restart it? I know its not like a car where you can turn it on and off.

  by DutchRailnut
The switching from diesel or electric mode is done on the fly just by moving a switch.
starting and stopping the engine is same, it takes a 3200 hp diesel a while to get up to 825 RPM , and diesel can not be used untill it reaches that speed.

  by 4 Express
I though a locomotive would switch to the appropriate power mode when it detects the power mode, guess not.

  by pnaw10
4 Express wrote:I though a locomotive would switch to the appropriate power mode when it detects the power mode, guess not.
I brought up a similar point awhile ago... if you want to search the older threads, you'll see more details. But for a quick summary, locomotives are manually switched from diesel to electric shortly before 125th Street.

Why? Apparently it's been tried before, and at higher speeds (ie. express trains making very few in the electrified zone) the third-rail pickup shoes can spark and cause fires. So most express trains from Poughkeepsie or Wassaic will run diesel all the way down to MO(yes?) or 125th until they switch to electricity.

  by 4 Express
Ok thanks pnaw10.

  by Clean Cab
Although the electric acceleration of the MN Genesis II P-32ACDM is quicker than deiesl mode, it was basically designed just to get the trains in and out of GCT. I run them in electric mode where ever there is 3rd rail, but since the top speed is only about 60 mph others choose to run in deisel mode as long as possible.