Between 1947 and 1959, dieselization on the Southern Pacific followed a predictable pattern. Order locomotives from the diesel builders similar to the other builder's early diesels but easier to maintain.
Competition from the Santa Fe and truckers caused a re-thinking of this pattern. The SP needed to move trains quickly or be left out of the high-speed high-value end of freight transportation. Thus the jump into turbo-charged locomotives offered by both EMD and GE.
Contents: Ch. 1: Introduction, pp. 3-5, Ch. 2: Cotton Belt and SP GP20 Locomotives, pp. 6-19, Ch. 3: Cotton Belt and SP GP20R Locomotives, pp. 20-31, Ch. 4: Cotton Belt and SP GP30 Locomotives, pp. 32-39, Ch. 5: Cotton Belt GP 35 Locomotives, pp. 40-47, Ch. 6: SP GP35 Locomotives-Original Numbers, pp. 48-57, Ch. 7: SP GP35 Locomotives-New Numbers, pp. 58-87, Ch. 8: Upgraded GP35R Locomotives, pp. 88-111, Ch. 9: Cabless DD35 Locomotives, pp. 112-119, Ch. 10: The Graduates (short line survivors), pp. 120-128.
Shade Tree Books, softcover, 128 pages, standard portrait book 8 x 10 in., B&W photographs with captions and rosters.