The Electro-Motive Division's SD50 was only marginally successful and
the model ran into numerous problems. The design fell far short of the
high quality, reliable, long-lasting locomotives that railroads had
become so used to purchasing from EMD. The locomotive was released by
the company in the early 1980s and was another attempt to provided a
higher-horsepower model to keep pace with General Electric's increasing
competition and its C36-7 model that offered more power than the SD40-2.
Unfortunately, EMD rushed the SD50 into production and it not only
suffered mechanical problems but also did irreparable damage to the
company's reputation as a respectable locomotive builder.
Interestingly, after the issues with the SD50 were corrected the
locomotive did prove to be quite reliable and today many remain in use
on Class I systems such as Kansas City Southern, CSX Transportation, and
When the EMD SD50 hit the market in 1980 GE was already well established
and was providing EMD more competition with every passing year.
Overall the SD50 was very similar to the SD40 series in terms of its
layout and design (although it was a bit longer at just over 71 feet and
included an extra 600 hp), and
its most striking difference was not in appearances at all but what was
under the “hood" as the locomotive carried new microprocessors and
electronics. In essence, the locomotive was a transition to the
present-day highly computerized models from the then "Dash 2" line that
providing EMD with so much success. Unfortunately for EMD the SD50 was
not the answer to quelling GE’s increasing market share.
While the locomotive provided sufficient power, rated at 3,600 using General Motors' 16-cylinder model 645F3B prime mover, it was habitually unreliable and prone to numerous mechanical troubles. Using General Motors'
latest D87 traction motor the locomotive could produce tractive effort
ratings on par with the SD40-2; 92,000 pounds starting and 82,100 pounds
continuous. To make matters worse the locomotive had a very
complicated electrical system and was a headache
for maintenance and shop crews. Not surprisingly because of the SD50’s
setback it was mostly a failure in terms of sales and only sold over
400 units when production ended in 1985.
To correct the flaws with the prime mover EMD moved quickly to launch the SD60 model, which it released in 1984. While the locomotive was more fuel efficient,
featured EMD’s new 710-G3A engine, and was much more reliable the
failures of the SD50 haunted the original design with less than 600
built. However, EMD manufactured several variants through 1995 which
sold relatively well and by the time production had ended on the SD60
more than 1,100 had been built. In any event, buyers for the SD50
included the Baltimore & Ohio (20, numbered 8576-8595), Chicago
& North Western (35, numbered 7000-7034), Chesapeake & Ohio (43,
numbered 8553-8575, 8624-8643), Conrail (135, numbered 6700-6834), Rio
Grande (17, numbered 5501-5517), Kansas City Southern (11, numbered
703-713), Missouri Pacific (60, numbered 5000-5059), Seaboard System
(81, numbered 8500-8552, 8596-8623), Southern (20, numbered 6506-6525).
While both models were only marginally successful and the market had
already turned heavily in favor of GE-built locomotives, the SD50 and
SD60 can continue to be found on railroads all across the country,
including Class Is. The SD50 was also the last EMD to be built solely
with the standard cab design as the SD60 was offered with the now
popular (and mandatory) wide-cab "safety" design (the SD70 was the last
EMD locomotive to receive any standard cabs and most were purchased by Norfolk Southern). It should be also be noted that EMD released the SD50F in 1985. This model was built solely for the Canadian National Railway
as a "cowl" design with 60 ultimately constructed. However, like the
original SD50 design the SD50F continues to have reliability issues
today even though many remain in service.
EMD SD50 Production Roster
Baltimore & Ohio
Chesapeake & Ohio
Chicago & North Western
Denver & Rio Grande Western
Kansas City Southern
SD50S Production Roster
Norfolk & Western
Another variant of the locomotive was the SD50S built just
when production on the model was beginning. The "S" regarded a shorter
frame making them just over 69 feet length. All six were purchased the
Norfolk & Western (numbered 6500-6505) and its order was completed
by December of that year. In any event, be on the lookout for the
locomotives, while together they can hardly be distinguished, compared
against other EMDs they can easily be picked out with their extremely
long frames compared to others like the SD40 and SD45 series. Non-Class
I operators of the SD50 today include the Reading & Northern,
Hudson Bay Railway, and Utah Railway.