Discussion related to commuter rail and rapid transit operations in the Chicago area including the South Shore Line, Metra Rail, and Chicago Transit Authority.

Moderators: JamesT4, metraRI

  by F40CFan
 
Just an FYI, MILW-West train 2220 this morning had 414 and 114 shoving. They must be deadheading one in as 2220 generally rates a single F40.

I couldn't tell which or if both were supplying power as I was riding in the lead car. I saw them when we came 'round the bend at Pacific Junction.

  by F40CFan
 
I guess I was wrong, I saw them last night and this morning at Western Ave. working together.

That brought some questions to mind;

I realize that no two locomotives are exactly alike, but wouldn't like locomotives be matched better than two locomotives of different types or technologies?

Bones was kind enough to explain the differences in acceleration between the F40s and MP36s and that made me wonder what happens as the train above accelerates from a stop. Does the F40 get held back because the MP36's environmentally friendly systems accelerate more slowly under 15 mph? What happens when it begins moving over 15 mph, does the F40 hold the MP36 back?

Regarding HEP. Does it matter which unit, first or second, supplies HEP? Everytime I've seen two F40s together it seems that the lead unit is supplying HEP. In the case of the above lash-up, I would think it would be more fuel efficient to run the MP36 in HEP mode and not the F40, even though the F40 is on the point.

Just curious. Thanks in advance for anyone who responds.

  by metrarider
 
F40CFan wrote: Regarding HEP. Does it matter which unit, first or second, supplies HEP? Everytime I've seen two F40s together it seems that the lead unit is supplying HEP. In the case of the above lash-up, I would think it would be more fuel efficient to run the MP36 in HEP mode and not the F40, even though the F40 is on the point.
Hmm, in my experience, it's usually (always?) the trailing locomotive providing HEP. This at least seems to be the case on the UP lines.

  by bones
 
In most cases we do run the trailer with HEP on a westbound train so we don't have to hear all the noise. In the morning going east we use the west unit. easier to shut it down at Chicago.

As for two different units together, it doesn't matter. Quite often in freight you see different unit MU'ed all the time.

  by F40CFan
 
Thanks.

My ears must be playing tricks on me. I could have swore that I heard the trailing unit on a couple of occasions reving up as the train departed. The other way makes more sense for the engineer, though.

What sparked my curiousity about different units being MU'ed was an article I remember reading a while ago where Norfolk Southern was only going to MU like units. I forget if it was for fuel economy or they thought it was less wear and tear on the equipment.

  by Tadman
 
That mickeymouse power match plan failed fast, I have an office on the ex-conrail route in northern indiana, and they never power match anything. It's usally something like GP40, 8-40CW, GP15, which is about as unmatched as I can think of... But great to watch, you can hear that GP15 coming for miles away - lots of stack talk without turbos.

  by F40CFan
 
Thanks for the info. It did seem a little much to try and keep like units together on a large railroad.