The Pennsylvania Railroad was an American Class I railroad that was established in 1846 and was headquartered in Philadelphia, Pennsylvania. It was so named because it was established in the Commonwealth of Pennsylvania.
The Pennsylvania Railroad's class B6 was its most successful class of switcher, or as the PRR termed them, "shifter". The PRR preferred the 0-6-0 wheel arrangement for larger switchers, whereas on other roads the 0-8-0 gained preference. The PRR used road locomotives, generally 2-8-0s, when larger power was required.
The Pennsylvania Railroad's class P5 comprised 92 mixed-traffic electric locomotives constructed 1931–1935 by the PRR, Westinghouse and General Electric. Although the original intention was that they work many passenger trains, the success of the GG1 locomotives meant that the P5 class were mostly used on freight. A single survivor, prototype #4700, is at the Museum of Transportation in St Louis, Missouri.
The Pennsylvania Railroad's class O1 comprised eight experimental boxcab electric locomotives built in 1930 and 1931. They were built in preparation for the New York to Washington Electrification project. They had the wheel arrangement classified as 4-4-4 in the Whyte notation. Although successful, they were not powerful enough for the railroad's increasingly heavy trains. For production, the PRR chose to concentrate on the P5 class, effectively an enlarged and more powerful version of the O1 with an additional pair of driving wheels.
The Pennsylvania Railroad DD1 was a class of boxcab electric locomotives built by the Pennsylvania Railroad. The locomotives were developed as part of the railroad's New York Tunnel Extension, which built the original Pennsylvania Station in New York City and linked it to New Jersey via the North River Tunnels. The Pennsylvania built a total of 66 locomotives in its Altoona Works; they operated in semi-permanently coupled pairs. Westinghouse supplied the electrical equipment.
The Pennsylvania Railroad's class DD2 electric locomotive was a single prototype locomotive never placed into series production. It was intended as an improved and simplified GG1 for use on the planned, but never built, extension of the PRR's electrification west of Harrisburg, Pennsylvania. The one locomotive produced was numbered #5800 and used in regular Baltimore tunnel helper service until it was scrapped in September 1962.
The Great Northern Railway's class Y-1 comprised eight electric locomotives with AAR 1-C+C-1 wheel arrangements. The locomotives were used on the 73-mile (117 km) electrified portion of the railroad, from Wenatchee, Washington to Skykomish, Washington, including the Cascade Tunnel.
The Pennsylvania Railroad's class FF1 was an American electric locomotive, a prototype numbered #3931 and nicknamed "Big Liz". It was built in 1917 to haul freight trains across the Allegheny Mountains where the PRR planned to electrify. "Big Liz" proved workable but too powerful for the freight cars of the time with its 4600 available horsepower and astonishing 140,000 lbf (620 kN) of tractive effort. Pulling the train it regularly snapped couplers and when moved to the rear as a pusher its force was sufficient to pop cars in the middle of the train off the tracks.
Pennsylvania Railroad class E2b comprised six experimental B-B electric locomotives built for the railroad by General Electric.
The Pennsylvania Railroad's class B1 comprised 42 switcher-type electric locomotives built between 1926 and 1935. They were of 0-6-0 wheel arrangement in the Whyte notation with 700 horsepower. As built, the first 28 locomotives in the 1926 order formed semi-permanently coupled pairs grouped in three classes.
The Pennsylvania Railroad's class AA1 comprised two experimental electric locomotives constructed in 1905 by the company's own Altoona Works with the assistance of Westinghouse. Intended as testbeds as the PRR began its electrification project, both locomotives remained service into the 1930s.
The Pennsylvania Railroad's class Q1 comprised a single experimental steam locomotive for dual service, #6130. PRR Board approved $595,000 for the construction of this experimental Class dual service locomotive on Oct,9 1940, it was built in March 1942, its streamlined shrouding, according to an interview of noted an interview of John W. Epstein, Special Projects Manager and vice president, Raymond Loewy & AssoC.,, was designed by Raymond Lowey, but due to WWII, there was no publicity about it. The Q1 was a duplex locomotive, it had a wheel arrangement of 4-6-4-4, comprising a four-wheel leading truck, two sets of driving wheels in a rigid locomotive frame, and a four-wheel trailing truck. The first group of six driving wheels was driven by a pair of cylinders mounted conventionally in front of them, while the rear four driving wheels were driven by cylinders mounted behind them on either side of the firebox.
The class D15 of the Pennsylvania Railroad comprised a solitary Lindner-system cross compound steam locomotive of 4-4-0 "American" wheel arrangement in the Whyte notation. The sole locomotive was #1515, built in 1892 at the PRR's Altoona Shops, it had very British lines with a full-length footplate, splashers, a six-wheel tender, and large 84 in (2,134 mm) drivers. It was built in 1892 by the PRR’s Altoona Works it remained in service until it was retired in 1945 and put in storage at the PRR’s Altoona Works and was scrapped in 1951.
Class D14 on the Pennsylvania Railroad was a type of steam locomotive with a 4-4-0 wheel arrangement in the Whyte notation. They were originally designated class P in the PRR's pre-1895 classification scheme. Twenty-two locomotives were built at the PRR's Altoona Works ; six in 1893 with 78-inch (1,981 mm) driving wheels, and sixteen in 1894 with 80-inch (2,032 mm) drivers, classified D14a. Later, all sixteen class D14a were rebuilt to class D14b with 68-inch (1,727 mm) drivers for secondary service after they were replaced in top-flight express service, while three of the six class D14 were similarly rebuilt to class D14c.
Class D7 on the Pennsylvania Railroad was a class of 4-4-0 steam locomotive. Fifty-eight were built by the PRR's Altoona Works between 1882–1891 with 68 in (1.73 m) drivers, while sixty-one of class D7a were constructed with 62 in (1.57 m) drivers.
The Pennsylvania Railroad's steam locomotive class D1 comprised thirteen 4-4-0 locomotives for express passenger service, constructed at the railroad's own Altoona Works during 1868–1872. They were the first standardized class of locomotives on the railroad and shared many parts with other standard classes.
The Pennsylvania Railroad's MP54 was a class of electric multiple unit railcars. The class was initially constructed as an unpowered, locomotive hauled coach for suburban operations, but were designed to be rebuilt into self-propelled units as electrification plans were realized. The first of these self-propelled cars were placed in service with the PRR subsidiary Long Island Rail Road with DC propulsion in 1908 and soon spread to the Philadelphia-based network of low frequency AC electrified suburban lines in 1915. Eventually the cars came to be used throughout the railroad's electrified network from Washington, DC to New York City and Harrisburg, PA. The ubiquitous cars became a commuting tradition during their long years of service in several major cities. and were known as "red cars" or "red rattlers". The cars ran in service with the PRR until the Penn Central merger in 1968 at which point they were already being marked for replacement by new technology railcars such as the Budd M1 and Pioneer III. After the bankruptcy of the Penn Central the remaining MP54s found themselves being operated by Conrail under contract with local commuter rail authorities. The last MP54 cars were retired in 1980-81 while engaged in Philadelphia suburban service with SEPTA.
The Pennsylvania Railroad's class H6, H6a, and H6b steam locomotives were of the 2-8-0 "Consolidation" freight type, the most numerous class on the railroad with 1,707 units and the second most prolific 2-8-0 class in North America, with the USATC S160 class rostering 88 units more. The three subclasses differed as follows:
The Pennsylvania Railroad's no. 2512 was a single de Glehn Compound 4-4-2 "Atlantic" type locomotive that the railroad imported from France in 1904.
The Pennsylvania Railroad's class K29s comprised a single experimental 4-6-2 "Pacific" type steam locomotive. Constructed by Alco-Schenectady, it was given road number 3395. Although only one demonstrator was constructed, the K29s would become the basis for the highly successful K4s Pacifics and L1s Mikados. The lone example spent most of its life on the PRR's Pittsburgh division main line and was retired around 1929.
