Western Railroad Discussion > UPRR SD9043AC vs. CSXT SD70AC

Recently had back to back trips, went south with UPRR SD9043AC 8047 leading, then went back north on a train with CSX SD70AC 746. Interesting way to compare the two. Both had the isolated Whisper Cab, nice. Very quiet...but allowed you to hear the nice thrumming of the EMD 710 engine in Throttle 8. 4300 HP on the UP unit, 4000 HP on the CSX unit. The CSX unit was newer, so, it had the upgraded computer screens, which are more similar to the GE screen...the older EMD I-screen was somewhat awkward and quite inferior to the way the information was displayed on the screen as opposed to a GE C44AC. Many of the UPRR SD9043AC's have had a software upgrade which gives you the better display, but, the 8047 still has the original display.

OK...naturally, liked the K-5 horn on the CSX unit. I'd have to say pulling power-wise, the units were comparable. Both units weighed 415,00 lbs.

As for the brakes, I greatly prefer the WABCO Epic electronic air brake on the UP unit as opposed to the New York Air Brake Knorr electronic air brake on the CSX unit. One nice touch with the Knorr brake on the CSX unit (UPRR units with the Knorr do not have this feature) is a little button on both the big air handle and the independent handle which you push to bail off the independents during a brake application. You can handle the automatic brake valve alone, and push the button on it, and not even have to touch the independent handle to bail the independents...a time-saver and a nice touch. But, this does not make up for the sloppiness of feel in the Knorr brake handle as opposed to the Epic. The movement in the Knorr is sloppy, and stiff. Hard to find the minimum service postion, no detent, and any other brake application can only be achieved by awkward bumping and feeling your way around. The movement on the Epic is much crisper and more precise. A nice detent for minimum reduction, and, even a detent for a 10 pound set...a feature even the nice old 26L brake valve does not have.

Both units, the CSX and the UP...offered a much more comfortable, enjoyable experience than running a GE C44AC. Very quiet and very nice. On the CSX unit, you could hear the beautiful K-5 five chime horn well enough to enjoy it, but it was not intrusive into the locomotive cab. I personally think that cab mounted airhorns should be outlawed by the FRA. After you make several trips with a rear-mounted horn, it is an unpleasant experience to get an older unit with a cab-mounted air horn, which damages the hearing of the operator over time, and gives me a headache halfway into the trip and jars my nerves in general.

How about the ride quality? I have heard that the SD9043s are rougher than an SD70.

The isolated cabs do give a little more of a spongy ride than the stock SD70M's (all these have the same HTR truck, of course). But it wasn't too bad. I've had some that were worse years ago, ironically, when the 9043AC's were brand new. Maybe they've done some work to the rubber mounts or something? The CSX unit rode quite well.

Any extra sponginess in ride quality in the I-cab is still a superior situation in my opinion to the tremendous vibration of a GE C44AC when you hit the 8th Notch. The vibration really starts when you go from 7 to 8. Funny thing...the Dash Nine, with the exact same FDL-16 does not seem to have this much vibration. I guess it's all that tremendous torque from the AC transmission that accounts for the difference.

I'm a CSX hogger, you want our SD70MAC's, you can have them damn things. Nobody around here like's them. Trade you for your new Evolution GE's. It was the 9043MAC that really got me hating EMD stuff when I worked for UP out of Chicago, they where always broke!, now our 70MAC's are no better and can't pull crap, give me an AC4400 any day.