The

Pennsylvania Railroad The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

class D1 (formerly Class A, pre-1895) comprised thirteen

4-4-0 4-4-0 is a locomotive type with a classification that uses the Whyte notation for the classification of steam locomotives by wheel arrangement and represents the arrangement: four leading wheels on two axles (usually in a leading bogie), four po ...

locomotives for express passenger service, constructed at the railroad's own Altoona Works (now owned by Norfolk Southern) during 1868–1872. They were the first standardized class of locomotives on the railroad and shared many parts with other standard classes. The PRR was the first American railroad to adopt the Westinghouse air brake, the first tests of which were made in September 1869; Class A locomotives were among those fitted with air brake equipment for those earliest tests. They remained in service until they 1945, and were all withdrawn and scrapped by 1946.

References

4-4-0 locomotives D01 Railway locomotives introduced in 1868 Scrapped locomotives Standard gauge locomotives of the United States Steam locomotives of the United States {{steam-loco-stub