EMD F Unit Diesel Locomotives

Unquestionably one of the most popular and recognizable diesel locomotives of all time, the EMD F-units married style, and versatility, power, and reliability. Arriving at a time when steam locomotives ruled the rails and diesels were relegated to supporting roles, the F's changed the face of railroading in North America forever.

Starting with the first FT in 1939 and progressing through the last FL9 in 1960, the F series of locomotives maintained a very similar appearance. The most notable part of all was the "bull dog" nose profile. This same front was used on the later and larger E models - E7, E8, and E9. It is a face which remains as popular with railfans and model railroaders today as it was in the 1940s.

Cabless booster or "B units" were available for most F unit models. Different railroads paired them in different ways as they built consists custom-tailored to each train.

This flexibility in power, as well as the versatility to handle freight or passenger trains, combined with their mechanical operating efficiency, offered a striking operational potential for railroads when compared to the steam locomotives these diesels would replace.

While new locomotive designs, most notably EMD's GP series, began replacing the F units by the 1950s, the locomotives continued to roam the rails well into the 1970s. Today, dozens remain preserved in museums and tourist railroads with a few even retained by railroads for their own executive train use.

While they may all look the same at first glance, each of the F models has its own place in history. Each of the following locomotive profiles includes a more detailed history, list of railroads which first purchased the engines and a list of known models that have been made in each of the major scales. (And for some that is a very long list!)

  • 01 of 06


    FT train

    Ryan C Kunkle

     The locomotive that started it all, the FT predates Electro Motive Corporation's purchase by General Motors (when EMC became EMD.) The A-B-B-A set of demonstrators toured the United States and proved that not only could diesels do the job of a steam locomotive, but they could also do the job of almost any steam locomotive, on any railroad. It was more than the start of a locomotive line, it was the beginning of a revolution.

  • 02 of 06


    F3 train

    Ryan C Kunkle

    Following WWII, production shifted to the F3 model. The "F" originally stood for "Freight" but with improvements in the engine, it came to mean "Fourteen" as in 1400 horsepower. This rating was not for a single unit, but a paired A-B set, each with its own 700 horsepower diesel engine. 

  • 03 of 06


    F7 train

    Ryan C Kunkle

    The F7 was the best-selling of the F unit models. Horsepower increased to 1500 for each pair of locomotives. From Maine to California, the F7 was the face of freight and passenger trains for a generation.

  • 04 of 06


    F9 train

    Ryan C Kunkle

     By the time production began on the F9 in 1954, EMD had already introduced and sound success with their GP7. Still, the old "covered wagon" was given one more upgrade to 1750 horsepower and sold to railroads still in the market for mainline power with a bit of style.

    Continue to 5 of 6 below.
  • 05 of 06

    FP7 / FP9

    FP9 train

    Ryan C Kunkle

     Similar internally to the F7 and F9, the FP models included a steam generator for passenger service. While these were options on other F units as well, the FP models also featured a slightly longer frame to accommodate the water tank for the boiler without sacrificing fuel capacity. All FP models were A units. They could be paired with B units of any model, however.

    Although marketed for passenger service, FP locomotives were equally capable of handling freight trains.

  • 06 of 06


    FL9 train

    Ryan C Kunkle

     The last and most unique of the F units, the FL9 was a custom fit for the unique commuter services in and out of Grand Central Terminal. Able to operate as a conventional diesel-electric or pick up electricity from a third rail, the locomotives could operate safely in and out of the long tunnel into New York. 

    The FL9 had a unique 5 axle design and were longer than the typical F. They marked the end of F unit production in 1960 and were among the last in regular service in the US, securing their place in history and preservation.