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 ...

's class O1 comprised eight experimental

boxcab A boxcab, in railroad terminology, is a locomotive in which the machinery and crew areas are enclosed in a box-like superstructure (from boxcar). It is a term mostly used in North America while in Victoria (Australia), such locomotives have been ...

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 or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas ...

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 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 twentieth ce ...

( UIC: 2'B2';

AAR AAR or Aar may refer to: Geography * Aar, a river in Switzerland, tributary of the Rhine *Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains * Aar (Dill), a tributary of Dill river in Germany, also in the bas ...

: 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, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles (ele ...

power output and drive

gear ratio A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage. Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission ...

. In addition, three O1 locomotives were fitted with

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...

equipment, three with Westinghouse, and two with

Brown Boveri Brown, Boveri & Cie. (Brown, Boveri & Company; BBC) was a Swiss group of electrical engineering companies. It was founded in Zürich, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1970 ...

. The O1b locomotives used a

Buchli drive The Buchli drive is a transmission system used in electric locomotives. It was named after its inventor, Swiss engineer Jakob Buchli. The drive is a fully spring-loaded drive, in which each floating axle has an individual motor, that is placed in ...

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 most populous city in the U.S. state of New Jersey and the seat of Essex County and the second largest city within the New York metropolitan area.New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

Pennsylvania Station Pennsylvania Station (often abbreviated Penn Station) is a name applied by the Pennsylvania Railroad (PRR) to several of its grand passenger terminals. Several are still in active use by Amtrak and other transportation services; others have been ...

. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

they were used on the "Susquehannock" between

Harrisburg, Pennsylvania Harrisburg is the capital city of the Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the 9th largest city and 15th largest municipality in Pe ...

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 Sunnyside, Queens in New York City. Description The yard is owned by Amtrak and is also used by New Jersey Transit. The shared tracks of the Long Island Rail Road (LIR ...

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

References

{{PRR locomotives 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