Chicago, Burlington and Quincy Railroad F3 #120, a 4-unit ABBA set built in 1947, hauling a 51 car freight in 1950. This is a Phase II (early) locomotive with a smooth passenger pilot, and a gyrating signal light.

Gulf, Mobile and Ohio Railroad F3 #881A. This is a steam generator-equipped locomotive in passenger service. It is a Phase I locomotive with a freight pilot (indented, no coupler doors).

The EMD F3 was a 1,500 hp B-B freight-hauling diesel locomotive produced between July 1946 and February 1949 by General Motors' Electro-Motive Division. Final assembly was at GM-EMD's La Grange, Illinois plant. A total of 1,111 cab-equipped lead A units and 696 cabless booster B units were built. The F3 was the third model in GM-EMD's highly successful F-unit series of cab unit freight diesels, and it was the second most produced of the series. The F3 essentially differed from the EMD F2 only in horsepower, and from the later EMD F7 in electrical equipment. Some later F3s had F7 traction motors, and were nicknamed F5 models.

Identification

As built, the only way to distinguish between the F2 and F3 was the nose number panels on the A units, which were small on the F3 and large on the F3 and subsequent locomotives. However, these could and were often altered by the railroad. Few F2s were built, however.

Most F3s have "chicken wire" upper grilles, while no F7s or later do; instead, they have a distinctive stamped stainless steel grille area running along the top of the bodywork. However, some later F3s were built with this, and many railroads updated their F3s to F7 lookalikes.

All F2s, F3s, F7s and F9s have twin exhaust stacks and four fans close together on their roofs, unlike the FT's four stacks and seperated pairs of fans.

Surviving F3 locomotives

Eleven F3s survive today at a variety of museums; nine are A units, while two are B units.

F3 phases

The identification of locomotive "phases" is a creation of railfans. EMD used no such identification. EMD kept track of the marketing name (F3) and individual locomotives' build numbers. During the production cycle of a model, EMD would make changes. To keep better track of the variations of locomotives identified the same by the manufacturer, railfans began referring to phases; critical changes to a locomotive line.

Despite not being official designations, the phase description is useful. However, many of the changes described are cosmetic, easily changed features of a locomotive; roof fans, body panels, grilles and the like could be and sometimes were updated or swapped.

The following are normally identified as F3 phases:

Phase I

Built from November 1946. High, flat-topped 36" roof fans. Top third body panel had "chicken wire" in openings only. Short rear vent panel. Center-third body panel with three equally-spaced porthole windows. D17 traction motors.

Phase II (early)

Built from February 1947. Top third body panel now had full-length "chicken wire". Long rear vent panel. Center third body panel now had two portholes; area between covered with chicken wire, over 4 smaller rectangular openings.

Phase II (late)

Built from December 1947. Roof radiator fans change to low, pan-topped items.

Phase III

Built from March 1948. Center third body panel now has no chicken wire between the portholes; the four rectangular openings now have louvres.

Phase IV

Built from August 1948. Chicken wire upper-third panel is replaced with full-length horizontal stainless steel grille.

"F5"

Built from October 1948 through end of F3 production in February 1949. D27 traction motors with heavier-duty cables fitted.

References

• Furhman, Jim. EMD F2-F3-F5 Phase Chart. Retrieved from http://members.aol.com/JFuhrtrain01/CF7frames/F3Phases/F2F3F5chart.html on January 2, 2005.