Under the Whyte notation for the classification of steam locomotives, a 2-10-4 locomotive has two leading wheels on one axle, usually in a Bissel truck, ten coupled driving wheels on five axles, and four trailing wheels on two axles, usually in a bogie. These were referred to as the Texas type in most of the United States, the Colorado type on the Burlington Route, and the Selkirk type in Canada.
Under the Whyte notation for the classification of steam locomotives, 2-10-0 represents the wheel arrangement of two leading wheels on one axle, ten powered and coupled driving wheels on five axles, and no trailing wheels. This arrangement was often named Decapod, especially in the United States, although this name was sometimes applied to locomotives of 0-10-0 "Ten-Coupled" arrangement, particularly in the United Kingdom. Notable German locomotives of this type include the war locomotives of Class 52.
Main components found on a typical steam locomotive include:
The Pennsylvania Railroad (PRR) K4 4-6-2 "Pacific" was its premier passenger-hauling steam locomotive from 1914 through the end of steam on the PRR in 1957.
The M1 was a class of steam locomotive of the Pennsylvania Railroad (PRR). It was a class of heavy mixed-traffic locomotives of the 4-8-2 "Mountain" arrangement, which uses four pairs of driving wheels with a four-wheel guiding truck in front for stability at speed and a two-wheel trailing truck to support the large firebox needed for sustained power. Although built for both passenger and freight work, they spent most of their service lives hauling heavy high-speed freight trains. Many PRR men counted the M1 class locomotives as the best steam locomotives the railroad ever owned.
The Pennsylvania Railroad's class K5 was an experimental 4-6-2 "Pacific" type, built in 1929 to see if a larger Pacific than the standard K4s was worthwhile. Two prototypes were built, #5698 at the PRR's own Altoona Works, and #5699 by the Baldwin Locomotive Works. Although classified identically, the two locomotives differed in many aspects, as detailed below. They were both fitted with a much fatter boiler than the K4s, but dimensionally similar to those of the I1s 2-10-0 "Decapods". Most other dimensions were enlarged over the K4s as well; the exceptions being the 70 square feet (6.5 m2) grate area and the 80 in (2.032 m) drivers.
The PRR S1 class steam locomotive was a single experimental duplex locomotive of the Pennsylvania Railroad. It was designed to demonstrate the advantages of duplex drives espoused by Baldwin Chief Engineer Ralph P. Johnson. It was the longest and heaviest rigid frame reciprocating steam locomotive that was ever built. The streamlined Art Deco styled shell of the locomotive was designed by Raymond Loewy.
A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. Numerous attempts at this type of locomotive were made, mostly without success. In the 1930s this type of locomotive was seen as a way both to revitalize steam power and challenge the diesel locomotives then being introduced.
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 mainly 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 National 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 class Q1, #6130, was a single experimental steam locomotive designed for dual service. The locomotive entered service in 1942, and retired in 1949 after accumulating a relatively low 165,000 service miles.
Class E6 on the Pennsylvania Railroad was the final type of 4-4-2 "Atlantic" locomotive built by the railroad, and second only to the Milwaukee Road's streamlined class A in size, speed and power. Although quickly ceding top-flight trains to the larger K4s Pacifics, the E6 remained a popular locomotive on lesser services and some lasted to the end of steam on the PRR. One, #460, called the Lindbergh Engine, is preserved at the Railroad Museum of Pennsylvania. It was moved indoors to begin preparations for restoration on March 17, 2010. On January 10, 2011, PRR #460 was moved to the museum's restoration shop for a two- to three-year project, estimated to cost $350,000. The engine is listed in the National Register of Historic Places.
Pennsylvania Railroad Class L1s were 2-8-2 "Mikado"-type steam locomotives that were used on the Pennsylvania Railroad during the early twentieth century. These 574 locomotives were manufactured between 1914 and 1919 by the railroad's own Juniata Shops as well as the Baldwin Locomotive Works (205) and the Lima Locomotive Works (25).
The Trail Blazer was a deluxe all-coach train, inaugurated between New York and Chicago via Pittsburgh, Pennsylvania on 17:25 schedule operated by the Pennsylvania Railroad. The trains departed New York City and Chicago every day at 4:30 pm and 3:00 pm, respectively, and arrived at the destination the next morning. The Trail Blazer was one of the first all-coach trains to provide premium services comparable to a Pullman train. The Trail Blazer name was first used in 1927 for the East St. Louis-Pittsburgh preferred freight VL-6.
Pennsylvania Railroad 1361 is a 4-6-2 K4 "Pacific" type steam locomotive built in May 1918 by the Pennsylvania Railroad's (PRR) Juniata Shops in Altoona, Pennsylvania. It hauled mainline passenger trains in Pennsylvania and commuter trains in Central New Jersey on the PRR until its retirement from revenue service in 1956. Restored to operating condition for excursion service in 1987, No. 1361 and its only surviving sister locomotive, No. 3750, were designated as the official state steam locomotives by the Pennsylvania General Assembly. In 1988, it was sidelined due to mechanical problems and was currently owned by the Railroaders Memorial Museum (RMM) in Altoona, Pennsylvania, who were currently attempting to return No. 1361 back to operation.
The Pennsylvania Railroad G5 is a class of 4-6-0 steam locomotives built by the PRR's Juniata Shops in the mid-late 1920s. It was designed for passenger trains, particularly on commuter lines, and became a fixture on suburban railroads until the mid-1950s. The G5 was the largest and most powerful 4-6-0 locomotive, except for a single Southern Pacific 4-6-0 that outweighed it by 5,500 lb.
A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive. The concept was first used in France in 1863, but was particularly developed in the early 1930s by the Baldwin Locomotive Works, the largest commercial builder of steam locomotives in North America, under the supervision of its then chief engineer, Ralph P. Johnson.
Pennsylvania Railroad 5550 is a mainline duplex drive steam locomotive under construction in the United States. With an estimated completion by 2030, the locomotive will become the 53rd example of the Pennsylvania Railroad's T1 steam locomotive class and the only operational locomotive of its type, as well as the largest steam locomotive built in the United States since 1952. The estimated cost of PRR 5550 was originally $10 million, but an updated projected cost of $7 million was released with the acquisition of an existing long-haul tender from the Western New York Railway Historical Society in August 2017. Construction began in 2014 with the casting of the locomotive's keystone-shaped number plate. Major components, including two Boxpok drivers, the prow, the cab, third-course boiler, and fire door have been completed.
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.
