The SD45 and SD45-2, A Unique Flared Design

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).

The SD45 and SD45-2 models were very similar to their early celebrity sisters, the SD40 and SD40-2, except that they included an extra two cylinders and 600 hp (with the 645E3 engine upgraded to 20 cylinders). Manufactured between 1965 and 1974 the models were built primarily for one purpose, to win the horsepower race with GE and Alco (at least before Alco threw in the towel and exited the locomotive business). The model was rated at 3,600 hp, carrying EMD’s standard cab design, a C-C layout (meaning they had six axles) and high-traction truck. As for the length, the model was built on the same frame as the SD40 series with the SD45 having a length of 65 feet, 9 inches and the SD45-2 a length of 68 feet, 10 inches.

Additional features included a dynamic brake (a system for temporarily employing traction motors as generators and using the resulting electromotive force to slow the train) and an airtight hood that kept out dust, dirt, and other particles from reaching internal components (to cool these critical components the SD45 featured a single air intake for electrical cooling, with a pressurized cooling system).

Unfortunately, this rush to win the horsepower race would backfire somewhat on EMD. The original models were very problematic and the 645E3 engine was often times prone to breaking done and unreliable. To make matters worse the locomotive was not very fuel-efficient and the added maintenance of the SD45 was not worth the extra 600 hp to most railroads.

Interestingly though, and perhaps it was because of EMD’s reputation of providing high quality, reliable locomotives the original SD45 sold quite well at over 1,200 units. However, by the time the "Dash 2" debuted in 1972 and had corrected most of the problems which plagued the model, railroads had already lost interest in the model and only a little over 100 were ever sold. Instead, railroads had come to love the SD40 series which would go on to make history with thousands produced through the mid-1980s.

Despite this the SD45 continues to soldier on for a number of shortlines and Regionals, like that of Montana Rail Link, which operates a whole fleet of the flared-radiator SD45s, unique of all second-generation locomotives. MLR actually even operates all designs of the model from the originals to the SDP45 (for passenger service, the unit carries a steam generator) and SD45X.

For more information on the SD45 series consider one (or both) of the books below. Mike Schafer’s Vintage Diesel Locomotives looks at virtually all of the classic builders and models from Alco PAs to early EMD Geeps. If you’re interested in classic EMDs, or diesels in general, this book gives an excellent general history of both.

Also, Brian Solomon’s The American Diesel Locomotive also studies many of the same diesel models and builders as Mr. Schafer’s publication although at nearly twice the size the book goes into a bit more detail than Vintage Diesel Locomotives and also covers newer models. All in all, though, both books are a great read and you shouldn’t be disappointed with them, not to mention that they are loaded with photos (many in color)!