Original service life

During World War I, the Reading Company constructed various designs of switcher locomotives from their own shops in Reading, Pennsylvania to serve their various rail yards and roundhouses across their system.^[1] In September 1918, a unique saddle tank locomotive rolled out of the Reading shops after being constructed from parts of an I-2a class 2-8-0. The locomotive was B-4a No. 1251, which ended up being the only tank locomotive to be rostered by the Reading after the end of the war.^[2] The locomotive was never meant to haul trains as it was a shop switcher, or 'goat' as they were often nicknamed, to tow locomotives in and out of the Reading's locomotive facility.

Multiple brand new locomotives were still being manufactured at Reading and others were continuously in need of repairs, so No. 1251 was kept busy shunting them throughout the shop.^[3] It was consistently cleaned and well-maintained, and its ease of operation made it well liked by crews. As the 1950s progressed the Reading was in the process of dieselizing their locomotive fleet, although No. 1251 remained on the active list the longest, the only thing forcing it into retirement was age. Its last revenue switching assignment occurred on February 8, 1963.

Preservation

George M. Hart was a steam locomotive historian who formerly worked with Reading Company for years. As the famed Iron Horse Rambles excursion trains were coming to an end, Hart decided to operate his own steam excursions in various parts of the Northeastern United States, and he founded his own private company Rail Tours Incorporated. In early 1964, Hart purchased No. 1251 from the Reading and after some repair work was completed, No. 1251 was put into excursion service over the Maryland and Pennsylvania Railroad in York County. Owing to its low fuel capacity, No. 1251 was also fitted with an ex-Reading tender to decrease the amount of stops it would require.^[4]

No. 1251's running gear and lubricator.

In October 1966, No. 1251 was formerly retired from excursion service after its flue time expired, and it was subsequently replaced by larger locomotives from the Canadian Pacific Railway, including 4-6-0 No. 972. Two years later, No. 1251 was sold to the Pennsylvania Historical and Museum Commission with the hopes of putting it on static display at Hart's future museum ground at Strasburg. No. 1251 was moved across the Strasburg Rail Road and was put in the yard of the new Railroad Museum of Pennsylvania for storage.^[5] As construction of the museum's building was almost completed in 1972, No. 1251 was outright donated to it as a permanent addition to their locomotive collection.^[5]

In 1982, museum volunteers worked to cosmetically restore No. 1251 to make it more presentable for public view, and when it was completed No. 1251 was moved inside the museum's main building,^[6] surrounded by a few Pennsylvania Railroad locomotives.^[7] As of 2023 the locomotive remains inside the museum,^[1] and there are no plans of restoring No. 1251 back to operating condition anytime soon.