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 ...

(PRR) class A1 was a class of

0-4-0 Under the Whyte notation for the classification of steam locomotives, represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven. The wheels on the earliest four-coupled locomotives were ...

type

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 ...

History

The class A1 was built from 1886 to 1892, when 0-4-0s were being used by other railroads. In time, larger

0-6-0 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles and no trailing wheels. This was the most common wheel arrangemen ...

locomotives were introduced and superseded them on other railroads. However, the Pennsylvania Railroad had many tightly-curving track ways, as well as lines running through suburban areas. The PRR thus elected to use the small locomotives to operate these tight and confined tracks. By the 1920s, class A1 was greatly replaced by the even larger class A5s, the largest 0-4-0s on the PRR at the time. By the 1950s, as the diesel switchers became available for easier and more efficient switching duties, the PRR started to replace the 0-4-0s and 0-6-0s (such as the class B6sb switchers) with diesel switchers. The last of the A1s were withdrawn in 1957, and all were ultimately scrapped.

References

{{PRR locomotives Steam locomotives of the United States A1 0-4-0 locomotives Standard gauge locomotives of the United States Railway locomotives introduced in 1886 Scrapped locomotives Shunting locomotives