Book excerpt: Introduced in the 1930s, efficient and adaptable diesel locomotives had all but displaced steam locomotives by 1960. This colorful photographic history examines the development, implementation, and operation of diesel locomotives from the gleaming pioneer Zephyrs of the '30s through today's 8000-horsepower beasts. In the course of examining the dawn and preeminence of diesel power, the author offers a glimpse of America's major railways -- both freight and passenger -- in stunning modern and period color photography. Manufacturers like EMD, Alco and GE are included. The final chapter describes the operation and maintenance of modern diesel locomotives, and an appendix lists where rail fans can see restored examples of early diesels today.