Western Railroad Discussion > BNSF ES44C4 Locomotive Question

Good Evening:

Are the BNSF ES44C4 locomotives have an unpowered center axle that raises when the locomotive gets below a certain speed? If so, do they perform better with heavy tonnage vs a conventional six axle locomotive?

Also, do these units have DC or AC traction motors?

Thank you in advance.

CSXT_8437 Wrote:
-------------------------------------------------------
> Good Evening:
>
> Are the BNSF ES44C4 locomotives have an unpowered
> center axle that raises when the locomotive gets
> below a certain speed? If so, do they perform
> better with heavy tonnage vs a conventional six
> axle locomotive?
>
> Also, do these units have DC or AC traction
> motors?
>
> Thank you in advance.


The ES44C4 locomotives are AC traction locomotives. As far as how they perform vs a DC traction C44-9W, the ES44C4 is supposed to be equal in terms of pulling power (tractive effort) with 2 less powered axles than the C44-9W. Both the C44-9W and the ES44C4 have 4400 horsepower.

SantaFeRuss

People always refer to the Dynamic Weight Distribution System as a axle raising system, not so, the cam and cylinders take transfer enough weight off the idle center axle to transfer it to the two outer powered axles. The ES44C4 have AC traction motors and I like them well enough, I run in territory where its a long steady drag of a climb for almost a hundred miles with only a few dips to increase train speed, the C4's just seem to do their thing just as well as any DC.

They suck. Every C4 I've run won't load right when you come out of dynamics. In up and down territory it's hard to keep your speed.

iceweasel03 Wrote:
-------------------------------------------------------
> They suck. Every C4 I've run won't load right when
> you come out of dynamics. In up and down territory
> it's hard to keep your speed.

I agree. They slip all the time. I rate them 75% as effective as a normal unit. They load VERY slow too. I took notes to make sure I wasn't crazy. I had BNSF 7000 ES44C4 at 20mph it was loading 15k lbs. Vs a normal GE AC was loading 75k lbs.



Edited 1 time(s). Last edit at 12/07/12 22:18 by Pinlifter.

Pinlifter, why would you compare this to a normal six axle AC unit? Its not meant to be one so of course its not going to be like one! Apples and oranges here my friend

The whole point of a C4 is to have the same performance of a 6 axel with only 4 traction motors. Some of us are noting they don't come close and with side effects. They might work on a light z train but heavy tonnage freight they perform poorly. Especially when you have to start and stop all the time.

Posted from iPhone

Of a six axle DC unit

This reminded me of a funny story. We had 3 C4's on a heavy freight. It was rated at 1.0hpt on paper. Coal loads on the sub are rated 0.6hpt. As we started to climb hill the engines weren't loading well. They performed so poorly I almost stalled out. I had coal trains catching up to me. The DS was so pissed off he personally called me asking for an explanation. We all have different experiences out there. This is mine. Things aren't always what they seem on paper.

Posted from iPhone

I have had them more times than I would like. They really are no better than four axle units in pulling and in dyno.

I had a little experience with them when they first came out. (then retired) I never used them on coal or grain, just intermodal or stack trains. 99% of the train & engine crew people had no idea they only had four motors, BNSF told us absolutely nothing about them, or how they were any different than any others in the herd. Even the RFE knew little or nothing about how they were any different. I knew, and I played with them a little when I had the chance. A few times, I would notch up quickly starting the train, just to see how they preformed in R-8 at low speeds, at the point of wheel slip. They would screech & howl, but generaly hold the rail if conditions were good. In R-8 they would settle down at about 10 mph, but at about 15, you could feel the weight dist. system de-activate and let the weight back down on the center axle causing another loud screech & a jump. I never could get a straight answer if the system fluctuated according to changing traction needs, or if it was simply "on or off". And I never could figure out if the system worked the same way in DB, but I thought the dynamics were very strong for just four motors. And I could never figure out if the lower unsprung weight of the center axle made it more likely to slide when using the independent, or if they had somehow reduced the brake cyl pressure slightly for those two axles. And, I was told that they center axles never actually clears the rail, the system will lift about 85% of it's weight. Not sure if later orders were refined or changed for better preformance.

My first post in a few years (I now have a new name).

I have used them in heavy grade territory many times. They are good locomotives when they are doing what they are supposed to, but for some reason, the software is very finicky and screwed up. Sometimes I get one on the lead that that does great and does exactly what a DC unit does as far as traction is concerned, and other times, you get about half of a locomotive for an entire trip (there goes my fuel card when I am being charged for Run8 fuel and only getting run 3-5 out of the unit for a few hours). Some of them have a glitch that limits their load to a max of about 15-20K all the up to 30mph, then once 30 is reached, you can observe the HP meter and TE meter jump up to normal levels, but on most trains in my territory, 30mph is never reached for a great amount of the run due to many long climbs. I have observed trailing units on the "Consist Monitor" screen doing the same thing.

I have had one on the point pulling a Z train (with two units) up Grand View, AZ (1.5%) that decided to drop it's load to the levels described above and would not come back. Our speed climbing the grade went from 30mph to ~18 or so. Wonder what would have happened if we had two of them.

The ride quality of the locomotive is not as good as their normal-rollerblade counterparts.

The main reason I dislike them is because of the dynamic braking. The maximum braking effort is comparable to the ES44DC when conditions are good, BUT the dynamic braking curve and the dynamic braking output compared to handle position is very very screwed up. It is almost like having the tapered dynamics of yesteryear. They give out too much DB effort in the lower handle settings and reach their maximum very early in the handle position. When the handle is in DYN 4-5 and the engineer requests more DB, they don't give any more because they are already maxed out. This makes for a a very sloppy DP doublestack train with a couple C4's on one end of the train and couple DC's on the other. No matter where the hogger is in the dynamic brake handle range (except for full dynos) one consist will be putting out a different amount of effort than the other, making the node drastically shift back and forth in the train, and when a lot of the cars are 350 ton 5-pack well cars, you can feel every one of those cars shifting back and forth.

If these units were designed to replace or to work alongside with DC units, why not have the braking curve set up to be IDENTICAL to a DC unit?

It will be interesting to see how EMD's answer to the C4 works out when they begin delivery in the First Quarter of 2013.

My guess would be that the EMD will work better simply because the software logic becomes simpler
for EMD.

Except when EMD's FIRE system doesn't work all the time and fails to do anything like the ACe I had two weeks ago. Thanks Windows XP!

Guess I should have said "theoretically" it will be simpler.