EMD SD70ACe series official thread (covers all variations)

[Allen Hazen]

Chrisf--
Thanks for correction, and link to a side view! I looked at the just-off-front view that MEC 407 had linked to, and it looked to me like a 4-axle, BB, unit: hence my comments. The photo you link to makes clear that it is an 8-axle, "BBBB," unit: so no weight problem. EMD and GE have both for many years provided 8-axle derivatives of domestic 6-axle models for use on meter-gauge railroads in Brazil (the first, back in the late 1960s I think, was EMD's DD45: an 8-axle derivative of the SD45).
--
Comment now that that has been clarified: many of the 8-axle meter-gauge units EMD provided were strictly DD units, with two rigid-frame 4-axle trucks (visually at least similar to the standard gauge trucks used on the domestic DD35 and DDX40 units), whereas GE has always used pairs of 2-axle trucks on span bolsters. It looks as if EMD is now doing things GE's way. (Imitation is the sincerest form of flattery!)

[Allen Hazen]

MEC407--
Hmmm… GE has, since the beginning, used six inverters (one per axle)on its Alternating Current CC locomotives, and EMD, after initially using only two (= one per truck, has seen the error in its ways and does things GE's way. Can we assume that both of these 8-axle derivatives also use one inverter per axle, for a total of eight?

[n01jd1]

Article about SD70ACe-T4 including video.

http://www.railwayage.com/index.php/tra ... Itemid=502" onclick="window.open(this.href);return false;

BTW,does the prototype run? I am curious to hear what a 4 cycle EMD sounds like.

One thing I noticed is that the SD70ACe-T4 is very quiet. In fact, I could only hear the GE on this M-434 with CSX 8909 in the lead in Ridgefield Park, NJ 1/9/2023.

[n01jd1]

SD 70 ACe-P4
or
GP 70 ACe

Does SD refers to a truck with 3 axles generally (C'C' Co'Co' A1A'A1A' Bo1'Bo1') or to a truck with 3 driven axles ??

*wink*
André

Originally the GP's which were all B-B , stood for General Purpose while SD stood for Special Duty or Super diesel and were and are all C-C. The P-4's which all have gone to the BNSF is closer to an A1A truck as the center axle is not powered and like the ES44AC4's the middle axle can be lifted to increase traction. From what I hear this doesnt work too well and crews would prefer an locomotive with 6 powered axles opposed to just 4. No 4 axle locomotives have been offered or designed for the North American freight market since the GP60. Progress rail (EMD's direct owner) has a 4 axle passenger locomotive with the F125 being the only offering.