I didn't know that the AC6000's got derated. I knew about the rest. My question on the SD-80s is if more HP is so needed why are these not selling? Course, EMD was able to get a couple hundred more horses out of the 16 cylinder 710, so maybe it just isn't needed. I know most of the 90s are 90/43s I see those all the time, but they have flat roofs whereas the H-MACs have angled roofs. Also, some of the UP H-Macs have that new Cab that is on the ACe. I saw a GEVO the other day. Gotta get the film developed before I can post it though.
You gotta check out this thread, GEVO included: http://www.trainboard.com/ultimatebb.php/ubb/get_topic/f/25/t/000328/p/1.html#000014
Yes, I don't know what the methodology used to determine which units were "derated"... however looking at some of my unedited digital photos, I can read the classifications are different on various units ( CW44-6 vs. CW60AC ). Harold
I assumed that like the SD45 it was a gas guzzler, but if the Horsepower was in such demand, i would still sell to more then just Conrail.
Welcome aboard, Brian! The UP derated some of it's AC6000's to 4400 HP. The designation on the cab is AC60-44CW, or something.
The big advantage of AC is in the motors. With DC motors, you can stall them out, which can cause the motors to burn up. Burn up usually means that the armature windings heat up and melt. An AC motor will not stall (by stall I mean burn up under the same circumstances). With an AC powered loco, you can actually hold the train on a hill by appling power to the traction motors. If one tried this with DC motors, they would cook. Also, AC locos can apply much more traction to the rail. There have been cases where SD80MACs have rolled the rail right out from under the loco on the NS.
I'm surprised they don't do that more often on the old D&RGW Moffat Route.... The trains they push over the mountain are heavy, and often just barely get enough power assigned to keep the tonnage moving. The curvature and grade of the line sure doesn't make it any easier! There were 2 stalled trains--one load at Tabernash, and an empty east of Rollinsville, that stalled on the 30th...