Question:
Could you tell me what is the most powerful locomotive that is still service on
the rails today?
Answer: Since this forum is primarily aimed at
answering questions or addressing issues from a trainmaster’s perspective, I’m
obliged to say that, as a trainmaster, I would really only be concerned with
whether or not I had the assigned power ready to go so I can depart my train on
time. I’m not going to be concerned
about the performance characteristics of the engines on my ready track. Locomotive assignment managers will, of
course, need to know that the engines they assign to the train are up to the
task (e.g., can the power consist reliably handle the load on the ruling grade?).
“Most
powerful” can be interpreted many ways.
There are some very high horsepower electric locomotives in service
today, in the US and in Europe. I would
judge a freight locomotive on its starting and continuous tractive effort
capability. What can it pull? Tractive effort is largely a function of the
horsepower from the primary diesel generator (aka prime mover), the locomotive’s
weight, and the adhesion at the wheel-rail interface.
There
may be others out there with more precise information, but I suspect the
locomotive in routine usage with the highest starting and continuous tractive
effort is the heavy-weight GE ES44AH used by CSX Transportation. This is basically a ballasted version of the
4400HP GE ES44AC. From what I've read,
the ES44AH has a starting tractive effort in the 200,000 lb range.
(There
are still some 6000HP EMD SD90 and GE AC6000 locomotives out there; however, I
have not read anything that suggests the starting or continuous tractive effort
provided by either significantly exceeds that of the latest 4400HP offerings
from EMD and GE.)
The
latest AC products from both EMD and GE, the SD70ACe and ES44AC, respectively,
have similar starting and continuous tractive effort capabilities (which may be
further enhanced with special adhesion control systems): both in the range of 180,000 – 190,000 lbs
starting and 160,000 lbs continuous.
Most modern North American trains can be easily handled by a pair of
either on other than mountainous terrain.
Thanks
for asking. I look forward to reading
the thoughts of others on this matter.
Stay safe out there.
Here
we go!
The SD70ACe clearly has the starting tractive effort advantage of the GE Evolution Series. At 191,000 lbs. it is close to the fully ballasted and compensated ES44AH units. The SD70ACe would even exceed the heavy weight ES44AH units if ballasted since the EMD wheel trucks have always outperformed the GE counterparts. This allows for a higher effective coefficient of friction with more starting tractive effort in a lighter locomotive.
ReplyDeleteTrainman, In actual running on CSX, the SD70Ace simply can't match the pulling power of a ES44AH, even with the SD70ACe ballasted up to the same 432,000 lbs weight. EMD can claim whatever figures it wants to, but in real operation, the ES44AH is a superior puller, and has the highest tonnage rating of any CSX locomotive
ReplyDeleteThe ES44AH has a higher continuous tractive effort rating than the SD70Ace by a small amount. I am sure that is what you are referring to. However, in the "real world," a ballasted SD70Ace could clearly start a heavier train than the ES44AH. That is due to the superior efficiency of the EMD radial wheel trucks. This has been the case for decades now. Trainman is correct.
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