Western Railroad Discussion > Do the ES44AC's pull as well as AC4400's?

Being an employee of CSX, I haven't had a chance to run any ES44AC's yet. With the CSX order supposedly being released soon, I was wondering if any of you UP or BNSF employees can tell me whether the AC GEVO's pull as well as their earlier counterparts. We have almost 600 AC4400's (CW44AC's in CSX speak) on CSX, and they are my favorite engine to have. I was wondering if I could expect similar results with ES44AC's? I've run plenty of CSX's ES44DC's, and while not as good as a CW44AC, they do OK... I guess. Thanks.

I've ran them on the apple and coal trains out of Chicago. They don't pull as well as our AC44s. They don't accelerate as well as the AC44 when under heavy load. When you first get into one you will feel the difference. The dynamics are like the DC versions ( shit ). Just my opinion.

I prefer the ES44AC over the AC4400 for the heavy pulling on the mountain. The grip better. The Dynos dig in better than the AC4400 does and has less tendency to jump when nearing a stop. This of course is on mountain grade where high acceleration is not needed.

YM

the DC version of the ES44's have a goofy KLB meter instead of amps, so it's hard for me to tell what it's doing. I know what 1500 amps fells like, but a short green line showing KLB's tells me little. Save that for the AC's. They have a very poor Dynamic Brake, the faster you are travelling, the weaker they are. They are pretty strong from about 35 mph down to a stop, but at higher speeds they are pretty weak. The older GE's would go to 900 amps or 100% in DB-8, and stay there right down to 2-3 mph. At higher speeds with a solid consist of the new ones, you'd better use some air with the DB if you want to slow down in a reasonable distance. If I have to cut out any DB's in a consist to stay in compliance, I cut out the new ones.

On BNSF's ES44AC's I've seen a lot of them with reduced dynamic brake error messages. Haven't had too many with problems, but the cab is a heck of an upgrade (at least for now). They are really quiet. They do load faster than the ac4400's.

Very interesting array of replies on this topic ....... could there be differences in specs between BNSF and UP units ?

ddg Wrote:
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> They have a very poor Dynamic Brake, the faster you are travelling,
> the weaker they are. They are pretty strong from about 35 mph down
> to a stop, but at higher speeds they are pretty weak. The older
> GE's would go to 900 amps or 100% in DB-8, and stay there right
> down to 2-3 mph.

I wonder if you are being confused by the TE display, as the retarding force should be about the same for both older and newer locomotives, assuming they both can hold their feet. While amperage in traction is proportional to tractive effort (transition excepted), in DB it does not give a direct reading of retardation.

As an example, if you have 900 amps at 60 mph, that same reading would result in twice the retarding force at 30 mph. As another example, if you have 900 amps at 30 mph, and reduce the retarding force until the ammeter reads 450 amps, you would not have 1/2 the retarding force, but only 1/4 the retarding force. That's because the retarding force varies as the square of the amperage at a given speed, and not directly in proportion as in traction.

Once the speed drops below about 30 mph, you start to get grid shunting to give extended range capability. All bets are off on the relationship between amps and retarding force at low speeds as a result.

Unlike the ammeter, the TE display would give you a direct reading of retardation in DB, so it is more useful. Once you get used to it, the TE display should be of more value.

thanks I'll soon be seeing them also.

I have run everything from a Alco, F-7, and every other possible unit. All I can say is that give me an EMD anyday! A GE locomotive was known as a 5 year locomotive because that is how long it lasted until it was ready for the junkpile!

SanJoaquinEngr Wrote:
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> I have run everything from a Alco, F-7, and every
> other possible unit. All I can say is that give
> me an EMD anyday! A GE locomotive was known as a
> 5 year locomotive because that is how long it
> lasted until it was ready for the junkpile!

They haven't been that way since the introduction of the Dash 8s. What you describe applies to the Dash 7s and earlier.

I run Gevo's and SD-70's and SD-70 AC's 6 days a week... i speak from experience.

I've read negative things about the EMD SD70ACes...and yet...I find them just as good as an SD70M (my true favorite), or SD9043AC. Louder than the SD9043AC with its Whisper Cab, no louder than an SD70M (except for the part about the excessively long "Cool Down Cycle" where the ACes run at Notch 3 RPMs...I find this unnecessary, feel that it wastes fuel, and it is irritating (not to mention that there is no reason whatsoever that an SD70ACe or SD70M-2 needs any longer of a revved-up Cool Down Cycle than an SD60, SD70, or SD9043AC. Perhaps a future software mod will cure this? Other than that...no complaints about the SD70ACe...and I'm still an EMD man. I did, I have to say, find the NS SD70M-2 that I got a bit "weaker" than not only an SD70ACe, but, the DC-motored SD70M that it succeeds (but I've heard similar "issues" with ES44DCs vs. Dash Nines). Seems like they've gotten it right with the ACs (both EMD and GE), but something is amiss with the DCs???

In direct response to the original question (what an array of opinions!!!), I've found that the newest C44ACs load quicker than the older ones, and the ES44ACs load even quicker than those. No slipping issues on my end.

I think that a lot of the complaints about the SD70ACes being "horrendously loud" come from CSX hoggers who are more used to their souped-up, Super Heavy (4300 HP vs. 4000, 432,000 lbs of weight) SD70MACs, which I concede are true Cadillacs, the newer ones, with a Whisper Cab that seems to be more securely fastened to the chassis than older units with the Whisper Cab.

I find that both the SD70ACe and ES44AC (but also the last of the 2004-model C44ACs) lack the "Boogie Shake" or "Earthquake Mode" characteristic of older ACs, both EMD and GE. I attribute this to more sophisticated control software--when the ACs first came out--I always assumed from the get-go that both EMD and GE would undoubtedly "fine-tune" this aspect of the units, and they have.

Another interesting point...I'm having trouble remembering whether the NS ES40DC that I had measured TE or amps. But, I do remember that the NS SD70M-2 measured its output in amps, and not TE (after hearing that TE measurement was an FRA requirement...this appears to nullify that argument? It appears to be a customer option...as the late-model UPRR SD70Ms do measure TE, and not amps). In my opinion, a DC-motored unit should display amps, pure and simple, while TE is fine for an AC.

Another odd thing about the NS ES40DC...it doesn't have the standard "GEVO Cab Arrangement." It has the "new" old AAR control stand, to be sure...and I like this...but unlike all other GEVOs that have the computer display screens directly in front of you, the NS ES40DCs retain the C40-9W computer display arrangement, where they are mounted right above the control stand. I suppose that this was done so that they would retain some degree of parts commonality and cab arrangement similarity with the large fleet of C40-9Ws? Or...just as the BNSF got a discount on its first batch of ES44DCs with desktop control stands, using up remaining in-stock desktops, perhaps this was the case with the NS GEVOs, and later/future models will have the standard GEVO setup?

I've had several NS SD70M-2s in trail...it was the one instance where I had one in the lead that the unit seemed to feel "sluggish," even on a train of moderate tonnage. I don't know...it could have been a "hard rolling train." Yes...sometimes...you just get a train where the tonnage being equal, it just isn't an "easy roller," while other times, you get a quite heavy train, and it just seems to be a "smooth roller." So...I'll reserve final judgment on the SD70M-2.

Bottom line: I think that both the SD70ACe and ES44AC are excellent locomotives. The SD70ACe...typical EMD: GOOD. The ES44AC? The most-improved GE product to date (though as I mentioned, late model C44ACs seem to be pretty good, too).

Perhaps the noise complaints against the SD70ACes will dissapate with new-build units, as 2008 models (not sure when the cutoff date is, January 1st???) will have to comply with decreased cab interior decibel requirements, both GE and EMD. Sounds like EMD will go back to a Whisper Cab, while GE will introduce something similar? I don't know, the GEVOs are pretty quiet inside, perhaps they already meet the new standard. But the EMDs will certainly get some modifications to meet the new interior noise requirement.

Red Wrote:
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> both GE and EMD.
> Sounds like EMD will go back to a Whisper Cab,
> while GE will introduce something similar? I
> don't know, the GEVOs are pretty quiet inside,
> perhaps they already meet the new standard. But
> the EMDs will certainly get some modifications to
> meet the new interior noise requirement.

I sure hope so! I agree that the SD70Ace is a good locomotive but its difficult to enjoy it with the loud cab.

Good post Red! I appreciate your inputs and thought that it was very well thought out! Cudos to you! The only thing I will say about the CSX SD70MAC-T1's 4700's and 4800's you speak of as "Cadillacs" is not true! I hate a modern EMD desktop controlled loco! It's is the most cold, un-ergonomically designed poor piece of ... that I have ever been on. Someone at london who has obviously never run a loco for longer periods on time designed it. The modern GE here on CSX out performs and out pulls a modern EMD every time! Back here on coal trains there are some things you can get away with with two CW44's or CW60's that the SD70AC's simply will not do! Not to mention the GE's have a way better time at holding the rail in wet conditions. I don't mind a SD70ACe as long as it is in trail behind me!