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 F2 and large on the F3 and subsequent locomotives. However, these could and were often altered by the railroad. Few F2s were built, however.
Early versions of the F3 had the "chicken wire" grilles along the top edge of the carbody. Later production featured a distinctive stamped stainless steel grille.
All F-units introduced after the FT have twin exhaust stacks and four radiator fans arranged close together atop their roofs, unlike the FT's four stacks and separated pairs of fans.
Read more about this topic: EMD F3