The Electro-Motive Diesel SD70ACe

Electro-Motive Diesel’s new SD70ACe debuted in 2005 and is not only the main competition to General Electric’s Evolution Series™ of road-switchers but also meets the EPA’s Tier 2 requirements for diesel locomotive emissions. Although the SD70 model has never been able to regain EMD's dominance as the number one locomotive builder (having lost that to GE in the 1980s) it was still a very successful design with a few thousand different versions of the model operating around the country today. The SD70 actually hearkens back to the days of the SD40 model and its successes. So successful was the series that one can spot them virtually any place on practically any given train (including Class Is), even today, over 20 years after the last SD40-2 rolled off of the assembly line!

EMD originally began as the Electro-Motive Corporation and has its beginnings in 1922 being based out of Cleveland, Ohio building inexpensive motorcars. With the purchase of the company in 1930 by General Motor, and more resources at its disposal the company began developing the precursor of the modern-day diesel-electric road unit (cabs and road-switchers), the streamlined trainset, which consisted of a powered car permanently attached to a few coaches (usually two or three cars). The most famous of these streamlined trainsets was the Burlington Zephyrs, a beautiful streamlined stainless steel creation (originally powered by Winton engines, which would also become a subsidiary of GM) that was extremely lightweight and fast. The original trainset, the Zephyr 9900, made headlines in 1934 when it completed a non-stop journey from Denver to Chicago in a little over 13 hours.

Because the power cars with these trainsets were permanently attached to the coaches EMC sought to design a locomotive free of this articulated setup but designed in such a manner that a railroad could still attach it to any passenger train and obtain the same, smooth streamlined look. This it did with the unveiling of the EA model in 1937, the first in a long line of passenger diesel locomotive designs that would come to be known as the E series.

Not surprisingly, soon after the EA unveiling the company decided to take things a step further and develop the first true diesel road unit, capable of pulling long freights in main line service. In 1939 it introduced the FT model (perhaps the key difference between the E and F series was that Fs rode on B-B trucks whereas Es rode on C-Cs and carried a noticeably longer carbody), the first in EMC’s F series and one of the most success diesel-electric designs of all time. The F series would go on to define American railroading for years and you can still see it in regular use today, over 60 years after it first debuted!

The FT (which stood for Freight, Twenty-seven hundred horsepower) was a superb locomotive and although its 2,700 horsepower came from an A-B setup of a cab (A) and booster (B) units rated at 1,350 horsepower each, it was quickly loved by railroads for the efficiencies it held over steam such as its ruggedness and ease of maintenance.

The FT (which stood for Freight, Twenty-seven hundred horsepower) was a serious locomotive and although its 2,700 horsepower came from an A-B setup of cab (A) and booster (B) units rated at 1,350 horsepower each it would become embraced by the rail industry for the efficiencies it held over steam power as well as being rugged and easy to maintain.

Following the success of its cab units, EMD realized that there was a market to be made in the road-switchers, which at the time was mostly dominated by Alco with its RS series. Its first attempt at this type of locomotive, which gave the train crews both excellent vision all around the locomotive for switching and local service as well as enough horsepower to be used in main line operations, was the BL2. Although unsuccessful from a sales standpoint the BL2 was really a mere stepping-stone for its next model, the GP series (meaning General Purpose).

Rated at 4,300 hp, the SD70ACe is essentially a more environmentally friendly version of the builder’s SD70 model and features EMD’s 16-710G3C-T2 engine, along with upgraded computer systems, electronics, and the builder’s famous self-steering trucks. While not quite as successful, to date, as GE’s Evolution Series™ sales nonetheless have been brisk (of note is the SD70M-2 which is the DC version of the SD70ACe). The table below lists those railroads which have purchased SD70ACes, including a few Regional railroads:

· BNSF Railway: SD70ACe – 270

· CSX Transportation: SD70ACe – 20

· Kansas City Southern: SD70ACe – 185

· Norfolk Southern: SD70M-2 - 130

· Union Pacific: 369 (Of note, units 1982, 1983, 1988, 1989, 1995, and 1996 wear a special “Heritage” livery denoting each large railroad that has been merged into UP since 1982.)

For more reading on EMD locomotives consider the book The American Diesel Locomotive from author Brian Solomon. The book studies everything from classic to newer diesel locomotive models. In all the book is a great resource and you shouldn’t be disappointed with it, not to mention that it is loaded with photos (many in color)!

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