During their career, which began with delivery of the first group in 1917 (except for a 1914 test engine), many members of the PRR's K4 class were the object of experimentation, upgrading, and other modifications. No. 1120, which belonged to that first 1917 group, was one of four that received a streamlining treatment, designed by Raymond Loewy, of the style depicted here. (No. 3768 had been streamlined in a different style.) An undesignated lensman snapped this view of No. 1120 at East St. Louis, Illinois, on October 6, 1948; Carl Weber provided the image for our collection. The dimensions of the K4s class are given in the commentary for No. 5492.