The EMD F Series, Defining a New Era of Motive Power
Along with the Electro-Motive Corporation’s E series, the later EMD F series, built primarily for freight service, would become the principal diesel-electric model to spell
the end for steam. The Electro-Motive Corporation (EMC) has its
beginnings in 1922 being based out of Cleveland, Ohio building
inexpensive motorcars. With the purchase of the company in 1930 by General Motors, 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 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 locomotive road unit, capable of pulling long freights in main line service. In 1939 it came out with the FT model (perhaps the key difference between the EMD F series and Es was that Fs rode on B-B trucks
whereas Es rode on A1As [which was a three-axle truck with the center
axle unpowered] 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 FT design also employed the new dynamic braking system, which
essentially was another means of braking that temporarily employed the
traction motors as generators and used the resulting electromotive force to retard (or slow) the train (very efficient and effective). The F series model would come to define American railroading for
years and you can still catch Fs in regular use even today! 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) plus booster (B), each rated at 1,350 horsepower, the model
would be embraced by the rail industry for the efficiencies it held
over steam power as well as being rugged and easy to maintain.
Like with the EA model, the Santa Fe was the first to jump on the bandwagon with the FT and ordered a whopping 320 A and B units
just by itself (it single-handedly purchased more FTs than Alco’s entire
line of PAs), and it did not take long for other railroads to follow
after seeing the locomotive’s capabilities. The FT became so successful
that before 1950 EMC had sold over 1,000 units! The FT essentially
became the standard by which all other similar cab models were designed by other manufacturers and it instantly made EMC the industry leader in diesel locomotives.
The FT’s success was only the beginning for the EMD F series. With the end of World War II wartime restrictions were lifted and EMC, by now known as General Motors’ Electro-Motive Division (EMD), was able to once again produce locomotives. The builder wasted no time ramping up production and soon unveiled the F3 (that followed the initial FT model) which sold some 1,111 units; the F7 followed next and sold 2,366 units; and last was the F9 which sold 87 units. Other than being upgraded to 1,500 horsepower (and 1,750 with the F9) over the FT’s 1,350 hp there were minor differences between the F3, F7 and F9 except for small overall changes and tweaks here and there. Amazingly all of these units were built in a time frame of a little over a decade, between 1945 and 1957.
The EMD F Series Line
555 A Units/541 B Units
74 A Units/30 B Units
1,111 A Units/696 B Units
2,366 A Units/1,483 B Units
100 A Units/154 B Units
Still In Production
Interestingly, later EMD F series designs included an FP model, the FP7 and FP9, which were essentially F7s and F9s except for an increased frame that allowed for a steam generator and added water capabilities for passenger service use. There were several built, over 400, but their numbers were far less when compared to the thousands of standard Fs manufactured. The success of the EMD F series is still incredible, even today, as its sales only fell slightly below that of its later sister models; GP7s, GP9s and SD40-2s. Like those models, Fs continue to roam the rails and likely will continue to do so for many years to come; not only because of their rugged nature and ease of maintenance but also because of the unit's clean and timeless streamlined design, allowing it to be a good choice even today for freight and passenger service.