Earlier this summer, I photographed UP 6161 at the NIPSCO, Michigan City Generating Plant in Michigan City, IN. I know that this plant gets its coal from the Powder River Basin. It is a GE model AC44CCTE. I’ve searched for an explanation of this unique designation, but have been unable to find anything. I’m sure it must be part of the GE AC4400CW family. Can anyone explain this to me? Thanks.
It’s a UP designation. On these units, the computer software that runs the inverters is considered “Controlled Tractive Effort”, the CTE after AC44C. It’s a UP AC4400CW.
So to give you the entire thing…it is an
AC, (alternating current) 4400 hp, C trucked locomotive with Controlled Tractive Effort, or an AC44CCTE,…simple, huh!
Try saying that three times really fast![:D]
That’s the only engine I ever see pulling UP coal drags around Central Texas. Always 2 or 3 in front and always one in back - I’m told the main purpose of the rear locomotive is fast air pressure in the brakepipe, not pushing.
Thanks for the reply. That makes sense to me.
It is a mouthful! Thanks for the insightful reply.
UP’s designation on the ES44AC GEVO is C45ACCTE, just for info. Also, come to think of it, the AC4400CW is a C44ACCTE, not an AC44CCTE.
Confused? Yeah, me too. That’s why I like the SD70ACe. 
So is the AC45CCTE 4500 HP then?
No, they did that to differentiate it from the older, 16-cyl model.
Ok then is the 45 a 12, 20 or other number of cylinders?
The “C45ACCTE” is a standard ES44AC Evolution Series with CTE software. It has a 12-cylinder GEVO engine in it.
So the AC44CTEs have 16 cyl prime movers and are the ‘older’ ones and the AC45CCTEs have the GEVO 12 cyl prime mover. Did I finally get that right?
Yes, That’s it! I think!
http://www.utahrails.net/all-time/current-index.php
Click on the road numbers in the left column. Notes on the pages that open are terrific.
C44AC Earliest of this family - deliveries began in 1995 (16 cylinder)
C44AC-CTE (2nd order units) Tier I emissions compliant. (16 cylinder) Numbered 5554-5694 and 5700 - 6081 (2001-2004 deliveries)
C45AC-CTE are current 12 cylinder GEVO power - Tier II [delivered 2005 +]
Confusion - GE * UP style!
1240 EMD SD70M’s began arriving in 2003. [Dem’z DC locos!]
One more helpful scorecard: http://www.thedieselshop.us/UP.HTML