The Pennsylvania Railroad’s slogan was “Standard Railroad of the World.” Often referred to as the Pennsy, the railroad was an early advocate of standardization, especially with motive power. This book highlights the steam, diesel and electric locomotives. Known for a “dog’s breakfast” of locomotives, Pennsy experimented with different types of locomotives until the found the right design. Highlighted are various classes of steam locomotives like the K4 4-6-2, S1 6-4-4-6 Duplex and T1 4-4-4-4 Duplex, diesel's like Alco RS models, Baldwin end-cab switchers, Fairbanks-Morse Train Master, Electromotive GP series, F-units and E-units, along with the legendary bi-directional, center-cab GG1 electric locomotive. System map, timetables, advertising and locomotive designs by Raymond Lowey, industrial designer for the Pennsylvania Railroad, are also featured from this previously unpublished collection of archival photos.