Locomotive classification on 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 ...

took several forms. Early on,

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

s were given single-letter classes. As the 26 letters were quickly assigned, that scheme was abandoned for a more complex system. This was used for all of the PRR's steam locomotives, and — with the exception of the final type bought (the E44) — all

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 also used this scheme.

PRR steam and electric classification

A: 0-4-0

Class A was the

0-4-0 Under the Whyte notation for the classification of steam locomotives, represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven. The wheels on the earliest four-coupled locomotives were ...

type, an arrangement best suited to small

switcher locomotive A switcher locomotive (American English), shunter locomotive (British English), station pilot (British English), or shifter locomotive (Pennsylvania Railroad terminology) is a locomotive used for maneuvering railway vehicles over short distanc ...

s (known as "shifters" in PRR parlance). Most railroads abandoned the 0-4-0 after the 1920s, but the PRR kept it for use on small industrial branches, especially those with street trackage and tight turns. * A1 * A2 * A3 * A4 * A5s * A6

B: 0-6-0

Class B comprised the

0-6-0 is the Whyte notation designation for steam locomotives with a wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles, and no trailing wheels. Historically, this was the most common wheel arrangement used o ...

type, the most popular arrangement for

s on the PRR. * B1 (Steam) * B1 (Electric) * B2 * B3 * B4 * B5 - Rebuilt from class H1 and H2a 2-8-0 * B6 * B7 - Some rebuilt from class H3, H3a, and H3b 2-8-0 * B8 * B21 * B22 * B23 * B28s * B29

C: 0-8-0

Class C was assigned to the

0-8-0 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of no leading wheels, eight powered and coupled driving wheels on four axles and no trailing wheels. Locomotives of this type are also referre ...

type. These were very common on other railroads, but the PRR was not keen on them and only built a few. This was partly because the PRR used

2-8-0 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, eight powered and coupled driving wheels on four axles, and no trailing wheels. ...

"Consolidation" types for similar service. * C1 - Largest 2-cylinder 0-8-0 ever built * C29 * C30 * C31

D: 4-4-0

Class D was the

4-4-0 4-4-0, in the Whyte notation, denotes a steam locomotive with a wheel arrangement of four leading wheels on two axles (usually in a leading bogie), four powered and coupled driving wheels on two axles, and no trailing wheels. First built in the ...

"American" type, the most common arrangement in 19th Century American railroading. 4-4-0s stayed in service on the PRR in secondary work later than on most other railroads, and three were in use until after

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 ...

* D1 * D2 * D3 * D4 * D5 * D6 * D7 * D8 * D9 * D10 * D11 * D12 * D13 * D14 * D15 - Compound * D16 * D21 - ex- Vandalia Railroad, built by Baldwin 1871-1873 * D22 - ex-Vandalia Railroad, built by Pittsburgh 1883-1889 * D23 - ex-Vandalia Railroad, built by Pittsburgh 1884 * D24 - ex-Vandalia Railroad, built by Rogers 1887 * D25 - ex-Vandalia Railroad, built by Pittsburgh 1890 * D26 - ex-Vandalia Railroad, built by Schenectady 1895-1899 * D30 - ex- Toledo, Walhonding Valley and Ohio Railroad, built by Rome 1890 * D31 - ex-Toledo, Walhonding Valley and Ohio Railroad, built 1892-1895 * D32 - Compound, ex-Toledo, Walhonding Valley and Ohio Railroad, built by Baldwin 1892 * D33 * D34 - ex- Cleveland and Marietta Railroad, built by Rome 1885 * D35 - ex-Cleveland and Marietta Railroad, built by Rome 1885 * D36 - ex-Cleveland and Marietta Railroad, built by Rogers 1885-1886 * D37 - ex- Cincinnati, Lebanon and Northern Railway, built by Baldwin 1894 * D38 - ex-Cincinnati, Lebanon and Northern Railway, built by Pittsburgh 1899 * D39 - ex-

Grand Rapids and Indiana Railroad The Grand Rapids and Indiana Railroad at its height provided passenger and freight railroad services between Cincinnati, Ohio, and the Straits of Mackinac in Michigan, USA. The company was formed on January 18, 1854. Beginnings After grapp ...

, built by Baldwin 1892-1893 * D61 - ex- Cleveland, Akron and Columbus Railway, built by Baldwin 1893 * "Odd D" #10003, an experimental

E: 4-4-2

The 4-4-2 "Atlantic" type was assigned class E. The PRR was an enthusiastic user of the Atlantic type in flatter country, and built some of the most advanced Atlantics used in the United States. * E1 * E2 * E3 * E4 * E5 * E6 * E7 * E21 * E22 * E23 * E28 - Compound * E29 - Compound * "de Glehn" #2512, a single experimental compound locomotive

F: 2-6-0

The

2-6-0 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, six powered and coupled driving wheels on three axles and no trailing wheels. T ...

"Mogul" type was assigned class F. On the PRR, this type was used during the period of 1895–1925, approximately. They were mostly used to haul express freight, although some hauled suburban passenger trains. * F1 * F2 - Compound * F3 * F21 * F22 * F23 * F24 * F25 * F26 * F27 * F30 * F31 * F61

G: 4-6-0

* G1 * G2 * G3 * G4 * G5 - Largest 10 wheeler built. PRR constructed 90 for use in commuter service and then built 30 for their subsidiary the Long Island RR. * G53 - Owned By subsidiary Long Island RR

H: 2-8-0

* H1 * H2 * H3 * H4 * H5 * H6 * H8 * H9 * H10

I: 2-10-0

The

2-10-0 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 of ...

"Decapod" type was assigned class I. The PRR only owned one type of Decapod, class I1s, but they owned 598 of them, one of the largest classes of identical power in the United States. * I1s/I1sa - heavy freight hauler.

J: 2-6-2 and 2-10-4

Class J was first used for two experimental

2-6-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels, six coupled driving wheels and two trailing wheels. This arrangement is commonly called a Prairie. Overview The maj ...

"Prairie" locomotives built by

ALCO The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer that operated from 1901 to 1969, initially specializing in the production of locomotives but later diversifying and fabricating at various time ...

in 1905. These were both withdrawn from service by the mid-1920s. In 1942, the PRR built 123

2-10-4 Under the Whyte notation for the classification of steam locomotives, a 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 bog ...

"Texas" type locomotives based on C&O plans; class J now being unoccupied, it was reused for them. The PRR J1 was an improved version of its C&O counterpart with more pulling power. * J1 - 2-10-4 freight locomotives. * J28 - experimental 2-6-2 locomotives.

K: 4-6-2

The PRR assigned class K to the

4-6-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The locomoti ...

"Pacific" type. The Pacific was the most common type of passenger locomotive on the Pennsylvania. * K2 - 153 built at Altoona 1910-1911 * K3s - 30 built by

Baldwin Baldwin may refer to: People * Baldwin (name), including a list of people and fictional characters with the surname Places Canada * Baldwin, York Regional Municipality, Ontario * Baldwin, Ontario, in Sudbury District * Baldwin's Mills, ...

in 1913. * K4 - 425 built by the PRR and Baldwin 1914-1928. * K5 - 2 prototypes built * K28s * K29s

L: 2-8-2

Class L was assigned to the

2-8-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, eight powered and coupled driving wheels on four axles and two trailing wh ...

"Mikado" type. * L1s - freight twin to the famed K4s Pacific (575 built) * L2s - the USRA standard light Mikado (5 built for PRR). * L5 - PRR 2nd generation DC electric locomotive. * L6 - PRR freight AC electric locomotives.

M: 4-8-2

* M1 - mixed-traffic Mountain type, latterly mostly used on fast freight.

N: 2-10-2

* N1s - Lines West heavy freight locomotive. * N2s - USRA Standard 2-10-2, also used on Lines West.

O: 4-4-4

The 4-4-4 arrangement was rare anywhere, and on the PRR it was found only on eight experimental electric locomotives. * O1 - experimental electric locomotives.

P: 4-6-4

The

4-6-4 , under the Whyte notation for the classification of locomotives, represents the wheel arrangement of four leading wheels, six powered and coupled driving wheels and four trailing wheels. In France where the type was first used, it is known as ...

arrangement was seen on the PRR only on electric locomotives. As a steam locomotive arrangement, it was poorly suited to the PRR's mountainous terrain, wasting much potential adhesive weight on non-driven wheels. That it was so widely used by the rival

New York Central The New York Central Railroad was a railroad primarily operating in the Great Lakes and Mid-Atlantic regions of the United States. The railroad primarily connected greater New York and Boston in the east with Chicago and St. Louis in the Midw ...

would also likely have factored against PRR adoption. * P5 - mixed-traffic electric locomotive, succeeded by the GG1.

Q: 4-4-6-4 or 4-6-4-4

The Q class comprised what were effectively 4-10-4s with the driving axles split into two driven groups. The Q2 was the most powerful non-

articulated An articulated vehicle is a vehicle which has a permanent or semi-permanent coupling in its construction. This coupling works as a large pivot joint, allowing it to bend and turn more sharply. There are many kinds, from heavy equipment to buse ...

steam locomotive ever built and also holds the record for highest horsepower recorded by any steam locomotive at 7,987 hp. * Q1 - experimental duplex freight locomotive. * Q2 - duplex freight locomotive.

R: 4-8-4

The PRR never built any steam locomotives of the

4-8-4 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type wa ...

"Northern" type, although the T1 duplexes were effectively a "Northern" with the driving wheels split into two groups. * R1 - experimental electric locomotive, surpassed by the GG1.

S: 6-4-4-6 or 6-8-6

Both S class locomotives were originally intended to only have four leading and trailing wheels, but for the S1 increases in weight required an additional axle at each end. In the case of the S2, it was due to wartime limits on the use of advanced steel alloys. * S1 - experimental duplex express passenger locomotive. * S2 - experimental

steam turbine locomotive A steam turbine locomotive was a steam locomotive which transmitted 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 ...

T: 4-4-4-4

The duplex-drive T1 was the final class of steam locomotive constructed for the Pennsylvania Railroad, and possibly the most controversial. * T1 - Duplex express passenger locomotive.

Compound classifications

The PRR classified

articulated locomotive An articulated locomotive is a steam locomotive (rarely, an electric locomotive) with one or more engine units that can move independently of the main frame. Articulation allows the operation of locomotives that would otherwise be too large to ...

s and joined locomotive units by using multiples of the previous classifications. Non-Articulated steam: *

1320 Year 1320 ( MCCCXX) was a leap year starting on Tuesday of the Julian calendar. Events January – March * January 5 – Henry III, Count of Gorizia, arrives in Padua as the Imperial Vicar with a large army, promising protection t ...

2-2-2-0 Under the Whyte notation for the classification of steam locomotives, 2-2-2-0 usually represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and no trailing wheels, but can also be ...

locomotive, based on the

London and North Western Railway The London and North Western Railway (LNWR, L&NWR) was a British railway company between 1846 and 1922. In the late 19th century, the LNWR was the largest joint stock company in the world. Dubbed the "Premier Line", the LNWR's main line connec ...

's Dreadnought Class locomotive. One built.Nock, O. S., et al. Railways at the Turn of the Century, 1895-1905. Blandford P., 1969. Articulated steam: * CC1s - 0-8-8-0

Mallet locomotive A Mallet locomotive is a type of compound locomotive, compound articulated locomotive, articulated steam locomotive, invented by the Swiss engineer Anatole Mallet (1837–1919). The front of the locomotive is articulated on a bogie. The Compou ...

. Treated as two

s for classification. One built. * CC2s - 0-8-8-0 Mallet locomotive. 10 built. * HC1s -

2-8-8-0 In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-8-8-0 is a locomotive with a two-wheel leading truck, two sets of eight driving wheels, and no trailing truck. Equivalent classifications Other equivalent ...

simple articulated locomotive. The PRR's only main-line articulated. One built. * HH1s -

2-8-8-2 A 2-8-8-2, in the Whyte notation for describing steam locomotive wheel arrangements, is an articulated locomotive with a two-wheel leading truck, two sets of eight driving wheels, and a two-wheel trailing truck. The equivalent UIC classification ...

Mallet locomotive. Treated for classification purposes as two

s back to back. * HH1 - 2-8-8-2 Norfolk & Western class Y3 borrowed by PRR during

. Articulated electric: * AA1 - experimental 0-4-4-0 or B-B electric locomotives. * BB1 - two-unit prototype AC electric 0-6-0+0-6-0 switching locomotive, later split into single units as class B1. * BB2 - two-unit 0-6-0+0-6-0 DC electric switching locomotives, later split into single units as class B1. * BB3 - two-unit 0-6-0+0-6-0 DC electric switching locomotives for LIRR, later split into single units as class B3. * DD1 - two-unit DC electric locomotive, two

half-locomotives semi-permanently coupled back to back. Served between Manhattan Transfer and

Penn Station Pennsylvania Station or Penn Station may refer to: Current train stations * Baltimore Penn Station * New York Penn Station ** Pennsylvania Station (1910–1963), the predecessor to the present New York City station * Newark Penn Station Train ...

, and to

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 ...

. * DD2 - experimental mixed-traffic AC electric locomotive, similar in overall design and appearance to GG1. * FF1 -

2-6-6-2 Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a is a locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and one pair of trailing wheels. ...

(1-C+C-1) experimental electric locomotive, 1917. Too powerful. * FF2 - 2-6-6-2 motor-generator AC electric locomotives acquired second-hand from the Great Northern Railway (their classes Y1 and Y1a) in 1956. * GG1 - express passenger and freight electric locomotive, highly successful.

Non-standard electric classification

* E2b - experimental B-B

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 ...

-built AC electric locomotives (3 pairs built). * E3b - experimental B-B-B

Baldwin-Lima-Hamilton The Baldwin Locomotive Works (BLW) was an American manufacturer of railway locomotives from 1825 to 1951. Originally located in Philadelphia, Pennsylvania, it moved to nearby Eddystone, Pennsylvania, Eddystone in the early 20th century. The com ...

- Westinghouse AC/DC rectifier locomotives (1 pair built). * E2c - experimental C-C

- Westinghouse AC/DC rectifier locomotives (1 pair built) * E44 - 1960 C-C

AC/DC rectifier freight locomotives. The horsepower-based designation unique to the E44 would be retained and expanded by

Penn Central The Penn Central Transportation Company, commonly abbreviated to Penn Central, was an American class I railroad that operated from 1968 to 1976. Penn Central combined three traditional corporate rivals, the Pennsylvania, New York Central and the ...

to cover the former

New Haven New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 U.S. census, New Haven is the third largest city in Co ...

EF4s (E33) and EP5s (E40).

Diesel classification

Source: The

was rather slow to dieselize. By the end of

WW2 World War II or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising ...

they only had 18 units. However over the next 22 years they had acquired a total of 3,005 units. The railroad purchased locomotives from all major American locomotive manufacturers: Alco with 516 units, Baldwin with 643 units, EMD with 1,479 units, Fairbanks-Morse with 200 units, General Electric with 145 units, and Lima-Hamilton with 22 units. This diversity was a nightmare for the maintenance department as there was very little compatibility amongst the different builders. ::The PRR's diesel classification system is as follows: ::The first letter in the classification stood for the manufacturer; ::* A -

American Locomotive Company The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer that operated from 1901 to 1969, initially specializing in the production of locomotives but later diversifying and fabricating at various time ...

(ALCO) ::* B -

Baldwin Locomotive Works The Baldwin Locomotive Works (BLW) was an American manufacturer of railway locomotives from 1825 to 1951. Originally located in Philadelphia, Pennsylvania, it moved to nearby Eddystone, Pennsylvania, Eddystone in the early 20th century. The com ...

(BLW) ::* E -

Electro-Motive Division Electro-Motive Diesel (abbreviated EMD) is a brand of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. Formerly a division of General Motors, EMD has been owned by Progress Rail since 2010. Electro-Motiv ...

(EMD/EMC) ::* G -

(GE) ::* F -

Fairbanks-Morse Fairbanks, Morse and Company was an American manufacturing company in the late 19th and early 20th century. Founded in 1823 as a manufacturer of weighing scale, weighing scales, it later diversified into pumps, engines, windmills, coffee grinder ...

(FM) ::* L - Lima-Hamilton Corporation (LH) :: ::The second and third letters represented the type of service; ::* S -

Switcher A switcher locomotive (American English), shunter locomotive (British English), station pilot (British English), or shifter locomotive (Pennsylvania Railroad terminology) is a locomotive used for maneuvering railway vehicles over short distanc ...

::* F - Freight ::* P - Passenger ::* PF - Dual Service/Mixed Traffic ::* RS - Roadswitcher ::* H - Helper :: ::The next number(s) were for the locomotives horsepower rounded to the hundreds. ::The last letter (if used), were for model variations.

American Locomotive Company (ALCO)

Baldwin Locomotive Works (BLW)

Lima-Hamilton (LH)

General Electric (GE)

Electro-Motive Division (EMC/EMD)

Fairbanks-Morse (FM)

References

{{DEFAULTSORT:Prr Locomotive Classification Locomotive classification systems Railway locomotive-related lists