Pennsylvania Railroad
In 1937, Loewy established a relationship with the Pennsylvania Railroad, and his most notable designs for the firm involved some of their passenger locomotives. He designed a streamlined shroud for K4s Pacific #3768 to haul the newly redesigned 1938 Broadway Limited. He followed by styling the experimental S1 locomotive, as well as the T1 class.
Later, at the Pennsylvania Railroad's request, he restyled Baldwin's diesels with a distinctive "sharknose" reminiscent of the T1. While he did not design the famous GG1 electric locomotive, he improved its appearance with welded rather than riveted construction, and he added a pinstripe paint scheme to highlight its smooth contours.
In addition to locomotive design, Loewy's studios provided many designs for the Pennsylvania Railroad, including stations, passenger-car interiors, and advertising materials. By 1949, Loewy employed 143 designers, architects, and draftsmen. His business partners were A. Baker Barnhart, William Snaith, and John Breen.[7]