What was the big difference between CSX's H15's and SD20-2's? I am guessing it has to do with h.p., electricals, and starting point. I'll post some photos. Harold
I can't help but notice that the carbodies on the H15's are remarkably short for 6 axle locomotives. They appear to be GP35 or 38 car bodies with flat flat back ends (like SDP35 ,40's or Tunnel Motors). I believe a very few did make it to CSX, but didn't last more than a few months under CSX.
EDIT: I found a picture of 1008 in CSX paint with a winged GE unit behind it, so they lasted until at least '86-'87. I thought for sure they were gone by 84.
H15's were rebuilt from SD/SDP35's, hence the shorter carbody. SCL/SBD removed the steam generators from the SDP35's after they were never in passenger service and shorted the hoods to regain the rear porch and also rebuilt the stairwells. I think the H15's were de-turbo'ed and re-rated at 1500 hp for hump yard service (notice the liberated 4 exhaust stacks), blanked out dynamic brakes, and paper air filters. The SD20-2's are something different... I am not sure if they were formerly SD40's and what exactly was done to them. The fact that they were called "-2's" implies that they had their electrical systems upgraded or overhauled. I have only photographed one and need to dig that photo up to compare. Harold
These SD20-2's are ex-B&O units.... Looks like they were de-turbo'ed, paper air filters added, dynamic brakes removed, and one of the radiator fans removed.... Harold
H15s were rebuilt from SBD SD35 and SDP35s (4 each)... the turbo was removed from the 567D3A. SD20-2 were rebuilt from B&0 SD35s in 79-80. The entire prime mover was replaced with a 645E (the same prime mover in the GP38/38-2), and the units were fitted with -2 electronics, making them SD38-2 equivalents. Note that it is possible to retrofit 645 power assemblies into 567 crankcases (as NS did with it's SD9Ms) however, on the SD20-2s, the entire prime mover was replaced...
I didn't realize the SD35/SDP35 was so short? I thought they were closer to the SD40/SD40-2 in length. Did they cut down the frame on these? Maybe it's the photos. They just look sooo short. Boxcab E50
SD35's were "short"... They were the first "modern" designed SD's that featured the angular cab I don't have the specific dimensions in front of me, but think the SD35 was ~ 5' shorter than an SD40; the SD40 was ~ 3' shorter than the SD40-2. Harold
SD35/P35 was built on the same frame used for the SD7/9/18/24/28 (and also the SD40X)... All have a 35' wheelbase and are 56' 6" over pilots...
Thanks, Robbman! Now that you mention it, that is why I predicted that Atlas would do an SD35 & SD24 (N Scale) after they re-released the SD7 & SD9 since they shared the same underframe. Harold
I thought the SD40X was based on the 40-2 and the testbed for the 50 series? Wouldn't it be on a larger frame?
I believe you are correct.... SD40X was built on the SD40-2 underframe and was a precursor to the SD50. A photo of a Soo unit is posted in one of the other TB forums: http://www.trainboard.com/ultimatebb.php/ubb/get_topic/f/75/t/000076.html Harold
There are two SD40Xs (as well as two GP40Xs)... One is the precursor to the 40-series, the other is the precursor to the 50-series... The original SD40X was built on a SD35 frame and was built as a true testbed for the 40-series in 64/65... The later SD40X wasn't originally built as a 50-series testbed (nor was the GP40X in 77/78) more of a tesbed for improving the 40-2... thus it was also a SD40X, (and not a SD50X) When EMD built the first production units for N&W, they called them SD50s (still built on a 45-2 frame). When they went to the longer frame, these were renamed SD50S' (S for short frame)
Here's a website with a picture of the earlier SD40X http://www.trainweb.org/dcstation/UP/UP3042.html I'm surprised EMD reused the name. Now that would be an interesting Kitbash. I have an SD-35 lying around, but I think I'd rather keep it intact.
