like PRR M1s, it was given larger-sized driving wheels at , which was as large as the Grand Trunk Western class U-4-b 4-8-4 "Northern" type. The Q1's streamlining was in the form of a bluntly-pointed nosecone on the smokebox front as well as extended side skirts covering up the locomotive's pipework. The cab front was set at a rakish angle. The tender, although given a freight locomotive's "doghouse" on the rear deck for the head-end brakeman, was otherwise a streamlined affair very similar to that used on the S1, S2, and T1 passenger locomotives. Q1 was the last dual service locomotive designed by the Pennsylvania Railroad, but there is no substantial evidence showing that it was assigned to passenger service. Q1's design was able to reduce dynamic argument by 60% compared to the J1 class above 70mph, but it exceeded the railroad's 50mph speed limit for the freight train. On April 10, 1942, H.W. Jones, Chief of Motive Power, told Altoona that the Q1, #6130, would be considered a passenger engine as far as striping and lettering were concerned. During its short service life, it spent more time in shops or the engine-house than being run, accumulating only about 165,000 service miles in its career (1942–1949). Its first revenue run occurred on May 31, 1942, from East Altoona to Enola with 125 cars and 10,000 tons; 40 mph was made on a level track at 40% cutoff. In October 1943, it was assigned to the St. Clair Avenue Enginehouse in Columbus, Ohio and ran mostly in the Ohio area and to Chicago. In December 1944, it appeared at a PRR exhibition in Chicago Union Station entitled "Presenting a Line of Modern Coal-Burning Steam Locomotives". At some time during the next year, it lost much of its streamlining, the nosecone being removed in favor of a conventional PRR smokebox front, including the keystone number plate placed centrally on the small smokebox door. A headlamp bracket mounted above that door also hung the locomotive's bell. The side skirting was cut back to expose pipework and fittings for easier maintenance. The skyline casing atop the boiler remained in place. The Q1 remained in service until July 1949, after which it was placed in storage. It was dismantled around 1949 and was removed from the company's books in January 1952. The PRR considered the Q1 design unfit for series production, and railroad historians consider