Any word out there on how these new locomotives are performing? I’ve heard mixed reviews for both. Any comments from locomotive engineers who have driven both would be welcome (also SD70M-2 and ES44DC comments welcome).
If these locomotives are as good out in the field as they are on paper, the performance must be incredible. The starting tractive effort on the AC versions (again, at least on paper) approaches a four-unit set of F units!!
I understand that the SD70ACe’s are causeing to many problems on the UP.
A mechanic in Proviso told me that neither type of new engines are working a well as they could (actually he told me they were both junk), and that SD40-2s and SD70Ms are still the best. This was, however, about 6 months ago, so they could (and most likely) have worked out the kinks by now.
SD70ACe’s have cab signal problems which means that they can not lead on the ex-CNW Geneva Sub (UP’s E-W main into Chicago.), so that’s one of the main problems with them, at least in the Chicago area.
As far as pulling power, they both are junk considering how new and sophisticated they are. Our shortline has one really severe grade at the beginning of our line, and we use run-through CSXT power on 60-car unit grain trains going up this grade, so any engines our line are really put to the test. The SD-90’s are also roughly the same too. The older SD-60’s and SD-70-MAC’s seem to pull much better.
So drfizzix - how do the slightly older sd-70mac’s and ac4400’s compare to each other on that grade? What percent grade is it?
i would have thought the SD70Ace’s would have been ok, account of the same engine used as the earleir SD70’s.
The power unit in a SD70 is not the same as in a SD70Ace or M-2 as they have had to comply with tier III emissions which the earlier units were not restricted to.
I seem to remember that the same question was asked about SD70MAC’s and AC4400CW’s
yeah…me too…thats weird
Both of the original SD-70’s and AC-4400’s pull pretty equivalentally to each other on that particular grade, but as others have noted, their better pulling performance than their successors may be due to the technical issues relating to meeting the strict emission requirements.
The grade, while it is certainly not the steepest in the country by any means at 1.54 %, is rough as our loaded unit trains have to go up that grade. The steepest grade on that line is a 2.2 % grade, but that is downhill for the loaded unit trains.