The engine was built by the Baldwin Locomotive Works in August 1908 for the Grand Trunk Railway as number 118. The 118 was renumbered 1708 in September 1919. In January 1923, the Grand Trunk Railway was merged into the Canadian National Railway. Three months after the creation of Canadian National, 1708 was renumbered 7157, a number the locomotive carried until February 1952 when it was renumbered 7240. In 1957, the locomotive received its final CN number of 7312.[1] In July 1958, No. 7312 was retired at Stratford, Ontario where it had been working as the shop switcher.
In June 1959, No. 7312 was discovered by Strasburg Rail Road Vice President Bud Swearer who was visiting the CN yard at Stratford. The Strasburg Rail Road had intended to purchase a steam locomotive to power freight and passenger excursions and No. 7312 was of appropriate size for the operation. The Strasburg Rail Road negotiated the CN for the locomotive, which was ultimately purchased by a consortium of Strasburg Rail Road officials. Arriving at Strasburg in the summer of 1960, the locomotive was renumbered 31 and placed into service on September 1, 1960, becoming the first steam locomotive to reenter service in the United States.[2] The locomotive was purchased outright by the Strasburg Rail Road in 1968.[3] The locomotive continued to remain in service up until early 2009 when 31(Backdated to 7312) was taken off the active roster for the locomotive's heavy rebuild. No. 31 has been stripped apart since then. However, due to the railroad's busy contract work and upkeep of their fleet of three other operable steam locomotives (GW 90, CN 89 and N&W 475) work was slow, if not non-existent. Steve Weaver, the VP of freight services on the railroad stated in an episode of " The Roundhouse Podcast" that the railroad indeed wants to get the engine back up and running again as the railroad has the time.[4] Work resumed in July 2021 with hopes to have it completed by early 2022 when no. 90 is due for its 1472. Currently, its cab and tender frame have been brought into the shop, though the tender tank has been left outside.