The

Pennsylvania Railroad The Pennsylvania Railroad ( reporting mark PRR), legal name as 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. At its ...

's class O1 comprised eight experimental boxcab

electric locomotive An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a Battery (electricity), battery or a supercapacitor. Locomotives with on-board fuelled prime mover (locomotive), ...

s built in 1930 and 1931. They were built in preparation for the New York to Washington Electrification project. They had the

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

classified as 4-4-4 in the

Whyte notation The Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twenti ...

( UIC: 2'B2';

AAR The Aare () or Aar () is the main tributary of the High Rhine (its discharge even exceeds that of the latter at their confluence) and the longest river that both rises and ends entirely within Switzerland. Its total length from its source to i ...

: 2-B-2). 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 eight locomotives were divided into four sub-classes — O1, O1a, O1b, and O1c. Each sub-class was fitted with a different combination of

traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, or electric multiple unit trains. Traction (engineering), Traction motors are used in electrically powe ...

power output and drive

gear ratio A gear train or gear set is a machine element of a mechanical system formed by mounting two or more gears on a frame such that the teeth of the gears engage. Gear teeth are designed to ensure the Pitch circle diameter (gears), pitch circles of e ...

. In addition, three O1 locomotives were fitted with

General Electric General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the year ...

equipment, three with Westinghouse, and two with Brown Boveri. The O1b locomotives used a Buchli drive between the traction motors and the driving wheels. were used, with two motors geared to each axle. They were generally employed in pairs by sub-class, generally on short-distance passenger trains between

Newark, New Jersey Newark ( , ) is the List of municipalities in New Jersey, most populous City (New Jersey), city in the U.S. state of New Jersey, the county seat of Essex County, New Jersey, Essex County, and a principal city of the New York metropolitan area. ...

and

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

's Pennsylvania Station. During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

they were used on the "Susquehannock" between

Harrisburg, Pennsylvania Harrisburg ( ; ) is the capital city of the U.S. commonwealth of Pennsylvania and the seat of Dauphin County. With a population of 50,099 as of 2020, Harrisburg is the ninth-most populous city in Pennsylvania. It is the larger of the two pr ...

and New York City. Later in life, they were used for transfer work around Penn Station and

Sunnyside Yard Sunnyside Yard is a large coach yard, a railroad yard for passenger cars in the Sunnyside neighborhood of Queens in New York City. The yard is owned by Amtrak and is also used by New Jersey Transit. The Pennsylvania Railroad (PRR) complet ...

, mostly hauling empty passenger stock. They were all out of service and scrapped by the mid 1960s.

References

{{Electric-loco-stub O1 11 kV AC locomotives 4-4-4 locomotives Experimental locomotives Passenger locomotives Electric locomotives of the United States Standard-gauge locomotives of the United States Scrapped locomotives Railway locomotives introduced in 1930