s1 began its passenger train services starting from december 1940, on the run between chicago and pittsburgh. on its first run out of fort wayne, indiana, the crew was led by h.h. lehman (fireman), c.j. wappes (road foreman) and frank ritcha (engineer). due to its gigantic size, s1 had to turn on chicago, burlington and quincy railroad's wye at chicago before going eastbound and was unable to go through the 130 lb switch (no.8) just to the west of pittsburgh union station this problem wasn't fixed until 1946 which also prevented the prr class t1 operating through pittsburgh).