In the late 1920s there were three companies involved in what was to become the Electro-Motive Division (EMD) of General Motors (GM). They were GM (of course), Winton Engine Company and Electro-Motive Company (EMC). EMC sold rail cars by buying components from various sources. Winton was one of them. GM was experimenting with two-cycle diesels. These were not ready so GM simply bought Winton in 1930. Meanwhile, EMC was in deep trouble as depression swept the country. EMC was Winton's biggest customer and EMC had knowledge about the railroad industry. That's why GM bought EMC, also in 1930.
GM released the Burlington Zephyr in 1934, using the Winton engine. The first E-units were supplied with the Winton engine, but in 1938 GM's own diesel was ready. It was a two-cycle diesel with a 567 cubic inch displacement (per cylinder) and it was simply called the 567 engine.
It was in the FT that GM's diesel first came into use. Until now every railroad had ordered steam engines with special features that no other railroad had, but GM wanted to sell only standard diesel units. Despite that fact (or thanks to it) the new FTs were a success. No other locomotive maker had any diesels during World War II and the FTs were the only ones allowed due to war restrictions as a diesel freight unit during the war. The first E-unit with GM's own diesel were the E3s in 1939.
New and improved F- and E-units followed. The peak was reached in the middle of the fifties when EMD manufactured 70 F-units per week. In 1941 the Electro-Motive Company was fully incorporated into GM and became the Electro-Motive Division of GM.
The sides on the F- and E-units could not be taken off, since they were an integral part of the body structure, with strengthening beams. This made it hard to service the engine and to replace it, when necessary. The GP-7 (first built 1949) and SD-7 (first built 1952) had a thick, strong frame and the entire body could be removed. The SDs and GPs could also run with the long hood forward, which the Es and Fs could not do. Sales of Fs and Es declined and other models took over.
General Motors' F-UNITS, The locomotive that Revolutionized
Railroading
by Daniel J. Mulhearn and John R. Taibi
ISBN-0-915276-39-9, Quadrant Press, Inc., Room 707, 19 West 44th St.,
New York, NY 10036. USA
Detailed history, many pictures.
F Units: The Diesels that Did It
by Jeff Wilson
ISBN 0-89024-374-3,
Kalmbach Books, USA
Not so detailed history, many pictures.
The second diesel spotter's guide
by Jerry A. Pinkepank
ISBN-0-89024-026-4 ,
Kalmbach Books, USA
About many types of diesels
Diesel Locomotives: The first 50 years. A guide to diesels built
before 1972
by Louis A. Marre
ISBN-0-89024-258-5,
Kalmbach Books, USA
About many types of diesels
Trains magazine. (Not much about early EMD-units in recent years)
Classic Trains Magazine.
Model Railroader Magazine. (Quite often there are articles about painting F-unit models with information about the real thing.)
Vintage Rails magazine. (No longer published, back issues available)
The F-unit Roundhouse (a great site about F-units)