Eastern Railroad Discussion > Tonight's Feature Locomotive

is the Conrail EMD SD-50.
After a boring day on the NS west of Conway, where there was one GE wide-cab after another, a little reminiscing is in order.
Starting in 1983 and ending in 1986, Conrail bought 135 of these sharp looking 3500 h.p.(some 3600 h.p.) units. They were numbered 6700-6834. Conrail used these EMD's on everything from coal drags to double-stacks. One time, I even saw a pair being used as helpers on the West Slope.
The SD-50 is 68 feet, 10 inches long and weighs 390,000 lbs. It is powered by a 16 cylinder 645 engine.
The 6707 wore a yellow ribbon that said, "We Support Our Troops".
It's amazing how these units seemed to be everywhere on Conrail, but now are a rarity on the NS.
Hope you enjoyed our look at the SD-50. Feel free to add any facts or figures I may have missed.

Andy

Top- Suffern, N.Y. 2/91
Bottom - Emmaus, Pa. 4/89

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Great shots as always Andy. Too bad the SD50 turned out to be such a lemon. Many ex CR units are sitting dead having been turned back to the lessors hands by NS and CSX. CR derated theirs to 3300 hp later BTW.
Larry

Like em or Hate em, I think they're still intresting units.

(feturing a less than spectacular EMD unit, I know this topic is gona get intresting)

Andy:

Caught 6756 on a grain train working one of the two elevators at Clymers, IN circa 1990 in the falling snow on the Logansport secondary line.

John

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What was it about the SD50s that made them unreliable? The 645 prime mover is tried and true, so was it something else?

The fact that the 645 was being pushed beyond it's limits. 3500-3800 thp was a lot to be asking of this design.

Despite all of the SD50's that have been parked, I have been seeing many more than you would think around Fort Wayne IN the past couple of months.(both original NS and former CR units. I don't know how many are left, but if they sent them all here to live out there lives, it would be fine with me. ANYTHING for variety!

Apperntly, the 645F series is not as dead as everyone likes to think, Motive Power seems to be having great luck with the revisions they have made (even geting them EPA friendly)

Tell me more.

I guy I knew had been an engineering intern at EMD during the GP/SP-50 era. He said the problem was EMD's "Mr. Turbocharger" had retired during the 40-2 period and when they went to boost the 16-645 to 3500 hp (from 3000hp) they botched the turbo, resulting in many costly turbo failures. I think there were also were software problems. All of this got fixed but once a dog always a dog.

Had to throw another one in here. Was up in Cumberland a few weeks ago and they were all over the place. This was a helper unit in Brunswick, MD this spring. One thing I heard about SD50's was that "one large fleet was completely rebuilt at EMD's expense", according to "The Contemporary Diesel SPotters Guide".

dharris

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