E21

E21 can refer to:

PRR 1223

Pennsylvania Railroad 1223 is a 4-4-0 "American" type steam locomotive built in 1905 for the Pennsylvania Railroad by the railroad's own Altoona Works for passenger service. After being retired from active service, the locomotive ran excursion trains on the Strasburg Railroad in Strasburg, Pennsylvania from 1965 to 1989 when it was removed from service requiring firebox repairs. Currently the engine is on static display at the Railroad Museum of Pennsylvania in Strasburg. It was listed on the National Register of Historic Places in 1979. The 1223 is the only surviving example of the Pennsylvania Railroad D16sb class.

History of class

The class D16 locomotives of the Pennsylvania Railroad were the most modern of a long history of 4-4-0 type steam locomotives that the railroad used. The 1223 was home built by the railroad at its Juniata Shops in Altoona, Pennsylvania, in 1905. As built it was a high speed passenger engine with tall driving wheels. However, the 4-4-0 type, long the mainstay of American passenger and freight service, was already becoming outmoded when the 1223 was built, being superseded by ever-larger engines. The Pennsy itself was pioneering steel passenger cars, which the public soon demanded for the implied increases in safety. The 1223 was eventually rebuilt with smaller driving wheels for local freight service, having been replaced on passenger trains by engines like the E6 Atlantics and K4 Pacifics. It was modernized as well, receiving superheaters [the "s" in D-16sb), piston valves, an electric headlight, and other improvements.

PRR 1737

The Pennsylvania Railroad's K4s class Pacific number 1737 was the prototype of the class of 4-6-2 steam locomotives that eventually would number 425 locomotives.

The Pennsylvania Railroad in 1914 needed a steam locomotive to haul the passenger trains that the smaller E class Atlantics (4-4-2) could not handle. The 1737 was the first K4s ever built for the PRR. In passenger service, the 1737 would handle passenger trains, like the railroads flagship passenger train, the Broadway Limited. As the 1930s began, the 1737 and the other K4s locomotives would have to double-head passenger trains. This is because the Pennsylvania Railroad had increased passenger service time tables. The K4s Pacifics were unable to keep up with the work. The "Standard Railroad Of The World" made a few attempts to replace the 1737 and its sisters. They were the classes: K5, S1, and the T1. None of the replacements were very successful in railroad service. With these being a failure, the K4s had to continue hauling passenger trains until the Pennsylvania Railroad replaced steam locomotives with the increasingly popular and less costly diesel-electric locomotives in 1957.

PRR 3936 and 3937

Coordinates: 39°58′56″N 76°9′40″W / 39.98222°N 76.16111°W / 39.98222; -76.16111

PRR 3936 and 3937, formerly 4781 and 4780 respectively, are a pair of DD1-class electric locomotives located in the Railroad Museum of Pennsylvania in Strasburg, Pennsylvania. The two locomotives form a married pair and were assigned an EZN of 36. The locomotives were put into service in 1911 and operated in the tunnels beneath the Hudson River between New Jersey and New York City until being relegated to yard work in 1924. 3936 and 3937 were donated to the Railroad Museum of Pennsylvania by Penn Central and are the only surviving locomotives of its class. They were listed on the National Register of Historic Places in 1979.

Design

Locomotives 3936 and 3937 consist of two separate DD1-class locomotives semi-permanently coupled back-to-back. Together, the pair have length of 64 feet 11 inches (19.8 m) and weigh 313,000 pounds (142,000 kg). DD1-class locomotives were nearly always operated as a pair—never individually and rarely as two pairs in a double-heading configuration. The locomotives were assigned an "Electrified Zone Number" (EZN) of 36; the EZN simplified train dispatching for each pair of DD1 while their original individual serial numbers were used for the mechanical records of the locomotives.