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The EMD SD50

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 Norfolk Southern.

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.

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. For a complete serial listing of new SD50s purchase please click here. Also, for technical data regarding the EMD SD50 please click here. Finally, for information about EMD's SD series please refer to the chart below.

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Electro-Motive Division's "Special Duty" Road Switchers

Model Type	Units Built	Date Built	Horsepower
SD7	188	1952-1953	1,500
SD9	471	1954-1959	1,750
SD18	54	1960-1963	1,800
SD24	179 A Units/45 B Units (Calfs)	1958-1963	2,400
SD28	6	1965	1,800
SDP28	5	1966	1,800
SD35	360	1964-1966	2,500
SDP35	35	1964-1965	2,500
SD38	53	1967-1971	2,000
SDP38	40	1967	2,000
SD38-2	81	1972-1979	2,000
SD39	54	1968-1970	2,300
SDL39	10 (Built For The Milwaukee Road)	1969-1972	2,300
SD40	1,275	1966-1972	3,000
SD40-2SS	5	1978	3,000
SD40X	4	1979	3,500
SDP40	20	1966-1970	3,000
SD40-2	3,957	1972-1986	3,600
SD40T-2	310	1974-1980	3,600
SD45	1,260	1965-1971	3,600
SD45X	7	1970-1971	4,200
SDP45	52	1967-1970	3,600
SD45-2	136	1972-1974	3,600
SD45T-2	247	1972-1975	3,600
SD50	361	1981-1985	3,500
SD50F	60	1985-1987	3,500
SD60/F/I/M/MAC	1,138	1984-1995	3,800
SD70	120	1992-2003	4,000
SD70M	1,646	1992-2003	4,300
SD70I	26	1995-2003	4,000
SD70MAC	1,124	1995-2003	4,000
SD70ACe	1,007	2003-Today	4,300
SD70M-2	130	2003-Today	4,300
SD75M	207	1994-1996	4,300
SD75I	207	1994-1999	4,300
SD80MAC	30	1995-1996	5,000
SD90MAC	40	1995-1996	6,250
SD90-43MAC	309	1992-1995	4,300

For more information on the EMD SD50 you might want to consider the book EMD Locomotives from author Brian Solomon. Solomon's book highlights the history of EMD from its earliest beginnings in the 1920s, to its phenomenal successes in the mid-20th century, and finally its decline into second spot behind General Electric in the late 20th century and eventual sale by General Motors in 2005. The book features 176 pages of EMD history and is filled with excellent photography and illustrations. If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.

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