This is a coal-burning, class M1b 4-8-2 steam locomotive that was built by the Pennsylvania Railroad's Altoona Works in 1930.

It is on display at the Railroad Museum of Pennsylvania in the town of Strasburg.

(James St. John, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons)

 

PRR green keystone logo.

PENNSYLVANIA RAILROAD LOCOMOTIVE CLASSIFICATION

Locomotive classification on the Pennsylvania Railroad took several forms. Early on, steam locomotives 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 locomotives also used this scheme.

 

PRR steam and electric classification

A: 0-4-0
Class A was the 0-4-0 type, an arrangement best suited to small switcher locomotives. 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 type, the most popular arrangement for switcher locomotives on the PRR.

  • B1
  • 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 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 "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 "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

  • 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, built by Baldwin 1892-1893
  • D61 - ex-Cleveland, Akron and Columbus Railway, built by Baldwin 1893
  • "Odd D" No. 10003, an experimental electric locomotive.

 

Builder's photo of PRR E1 4-4-2 Camelback No. 820.

(Pennsylvania Railroad, W. Lenheim Collection)

 

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" No. 2512, a single experimental compound locomotive

 

F: 2-6-0
The 2-6-0 "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

 

Pennsylvania Railroad Class H6 2-8-0 locomotive No. 2106, 1907.

(Andy Dingley (scanner), Public domain, via Wikimedia Commons)

 

H: 2-8-0

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

 

I: 2-10-0
The 2-10-0 "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 - heavy freight hauler.

 

J: 2-6-2 and 2-10-4
Class J was first used for two experimental 2-6-2 "Prairie" locomotives built by ALCO in 1905. These were both withdrawn from service by the mid-1920s. In 1942, the PRR built 123 2-10-4 "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.

 

Pennsylvania Railroad streamlined class K4s steam locomotive No. 1120

(Pennsylvania Railroad, Public domain, via Wikimedia Commons)

 

K: 4-6-2
The PRR assigned class K to the 4-6-2 "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 in 1913.
  • K4s - 425 built by the PRR and Baldwin 1914-1928.
  • K5 - 2 prototypes built

 

L: 2-8-2
Class L was assigned to the 2-8-2 "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 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 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 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 "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.

 

Photo of a Pennsylvania Railroad streamlined steam locomotive T1 class.

(The Wilkes-Barre Record, Public domain, via Wikimedia Commons)

 

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 locomotives and joined locomotive units by using multiples of the previous classifications.

Non-Articulated steam:

  • 1320 - 2-2-2-0 locomotive, based on the London and North Western Railway's Dreadnought Class locomotive. One built.

 

PRR HH1 2-8-8-2 Mallet locomotive.

(Pennsylvania Railroad, Public domain, via Wikimedia Commons)

 

Articulated steam:

  • CC1s - 0-8-8-0 Mallet locomotive. Treated as two 0-8-0s for classification. One built.
  • CC2s - 0-8-8-0 Mallet locomotive. 10 built.
  • FG1 - What could have been the PRR's version of the Norfolk & Western class A 2-6-6-4 simple articulated locomotive. Never built.
  • HC1s - 2-8-8-0 simple articulated locomotive. The PRR's only main-line articulated. One built.
  • HH1s - 2-8-8-2 Mallet locomotive. Treated for classification purposes as two 2-8-0s back to back.
  • HH1 - 2-8-8-2 Norfolk & Western class Y3 borrowed by PRR during World War II.

 

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 4-4-0 half-locomotives semi-permanently coupled back to back. Served between Manhattan Transfer and Penn Station, and to Sunnyside Yard.
  • DD2 - experimental mixed-traffic AC electric locomotive, similar in overall design and appearance to GG1.
  • FF1 - 2-6-6-2 (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-built AC electric locomotives (3 pairs built).
  • E3b - experimental B-B-B Baldwin-Lima-Hamilton-Westinghouse AC/DC rectifier locomotives (1 pair built).
  • E2c - experimental C-C Baldwin-Lima-Hamilton-Westinghouse AC/DC rectifier locomotives (1 pair built)
  • E44 - 1960 C-C General Electric AC/DC rectifier freight locomotives.
  • The horsepower-based designation unique to the E44 would be retained and expanded by Penn Central to cover the former New Haven EF4s (E33) and EP5s (E40).

 

Diesel classification

The Pennsylvania Railroad was slow to dieselize. By the end of WW2 they only had 18 units. However over the next 22 years they had acquired a total of 3005 units. They bought from all the manufacturers: Alco 516 units, Baldwin 643 units, EMD 1,479 units, Fairbanks-Morse 200 units, General Electric 145 units, and Lima 22 units. This diversity was a nightmare for the maintenance department as there was very little compatibility amongst the different builders.

The class number system is as follows:
The first letter stood for the manufacturer; A=Alco, B =Baldwin, G =General Electric, E =EMD, F =Fairbanks-Morse, and L =Lima.
The second and third letters represented the type of service; S =switcher, F =Freight, P =passenger, :: PF=dual service, RS =road-switcher, and H =helper.
The next number(s) were for horse power rounded to hundreds.
The last letter, if used, was for model variations.

 

Alco
See also: List of ALCO diesel locomotives

PRR Class Builder’s Model Build date Total produced Wheel arrangement Service Power output Notes
AF15 FA-1 1948–1950 8 B-B Freight 1,500 hp (1,120 kW)
AF15 FB-1 1948–1950 8 B-B Freight 1,500 hp (1,120 kW)
AF16 FA-2 1951 24 B-B Freight 1,600 hp (1,190 kW)
AF16 FA-2 1951 12 B-B Freight 1,600 hp (1,190 kW)
AF24 C-424 1962 1 B-B Freight 2,400 hp (1,790 kW)
AF25 C-425 1964–1965 31 B-B Freight 2,500 hp (1,860 kW)
AF27 C-628 1965 15 C-C Freight 2,750 hp (2,050 kW)
AF30 C-630 1966 15 C-C Freight 3,000 hp (2,240 kW)
AF36 C-636 1968 15 C-C Freight 3,600 hp (2,680 kW) ordered but del to PC
AFP20 PA-1 1947 10 A1A-A1A Pass 2,000 hp (1,490 kW) many converted to Freight
AFP20 PB-2 1947 5 A1A-A1A Pass 2,000 hp (1,490 kW) many converted to Freight
ARS10 RS-1 1948–1952 27 B-B Freight 1,000 hp (750 kW) 5 units used in Pass service
ARS15 RS-2 1948 6 B-B Freight 1,500 hp (1,120 kW) ex D&H
ARS16 RS-3 1951–1955 115 B-B Freight 1,600 hp (1,190 kW) 45 units used in Pass service
ARS16a RSD-4 1952–1953 6 C-C Freight 1,600 hp (1,190 kW)
ARS18 RS-11 1956–1957 32 B-B Freight 1,800 hp (1,340 kW)
ARS18a RSD-12 1957–1958 25 C-C Freight 1,800 hp (1,340 kW)
ARS20 RS-11 1956–1957 6 B-B Freight 2,000 hp (1,490 kW)
ARS24 RSD-15 1956 6 C-C Freight 2,400 hp (1,790 kW)
ARS24 RS-27 1962 15 B-B Freight 2,400 hp (1,790 kW)
ARS24s RSD-7 1955–1956 5 C-C Pass 2,400 hp (1,790 kW)
AS6 S-1 1947–1951 40 B-B Switcher 600 hp (450 kW)
AS10 S-2 1948–1954 90 B-B Switcher 1,000 hp (750 kW) 22 units MU class AS10m
AS10a T-6 1958 6 B-B Switcher 1,000 hp (750 kW)
ARS15 RS-2 1948 6 B-B Freight 1,500 hp (1,120 kW) ex D&H
ARS16 RS-3 1951–1955 115 B-B Freight 1,600 hp (1,190 kW) 45 units used in Pass service
ARS16a RSD-4 1952–1953 6 C-C Freight 1,600 hp (1,190 kW)
ARS18 RS-11 1956–1957 32 B-B Freight 1,800 hp (1,340 kW)
ARS18a RSD-12 1957–1958 25 C-C Freight 1,800 hp (1,340 kW)
ARS20 RS-11 1956–1957 6 B-B Freight 2,000 hp (1,490 kW)
ARS24 RSD-15 1956 6 C-C Freight 2,400 hp (1,790 kW)
ARS24s RSD-7 1955–1956 5 C-C Pass 2,400 hp (1,790 kW)
ARS24 RS-27 1962 15 B-B Freight 2,400 hp (1,790 kW)
AF24 C-424 1962 1 B-B Freight 2,400 hp (1,790 kW)
AF25 C-425 1964–1965 31 B-B Freight 2,500 hp (1,860 kW)
AF27 C-628 1965 15 C-C Freight 2,750 hp (2,050 kW)
AF30 C-630 1966 15 C-C Freight 3,000 hp (2,240 kW)
AF36 C-636 1968 15 C-C Freight 3,600 hp (2,680 kW) ordered but del to PC

Baldwin Locomotive Works
See also: List of Baldwin diesel locomotives

 

PRR Class Builder’s Model Build date Total produced Wheel arrangement Service Power output Notes
BS6 VO-660 1942–1945 12 B-B Switcher 600 hp (450 kW)
BS6 DS-4-4-660 1942–1945 99 B-B Switcher 660 hp (490 kW)
BS7 DS-4-4-750 1951 24 B-B Switcher 750 hp (560 kW)
BS7 S8 1951 7 B-B Switcher 750 hp (560 kW)
BS10 VO 1943–1945 8 B-B Switcher 1,000 hp (750 kW)
BS10 DS-4-4-1000 1948–1950 137 B-B Switcher 1,000 hp (750 kW)
BS12 S-12 1951–1956 98 B-B Switcher 1,200 hp (890 kW)
BS24 RT-624 1951–1954 24 C-C Transfer 2,400 hp (1,790 kW)
BF15 DR-4-4-1500 1940–1950 34 B-B Freight 1,500 hp (1,120 kW) Cab (A) aka “Sharknose”
BF15 DR-4-4-1500 1940–1950 34 B-B Freight 1,500 hp (1,120 kW) Cab (B)
BF16 RF-16 (A) 1950–1952 72 B-B Freight 1,600 hp (1,190 kW) Cab (A) aka “Sharknose”
BF16 RF-16 (B) 1950–1952 30 B-B Freight 1,600 hp (1,190 kW) Cab (B)
BP60a DR-12-8-3000 1947–1948 24 2-D-D-2 Pass 3,000 hp (2,240 kW) converted to helper aka "Centipede"
BP20 DR-6-4-2000 1948 18 A1A-A1A Pass 2,000 hp (1,490 kW) Cab (A)
BP20 DR-6-4-2000 1948 9 A1A-A1A Pass 2,000 hp (1,490 kW) Cab (B)
BRS10 DRS-4-4-1000 1949–1950 6 B-B Pass 1,000 hp (750 kW)
BRS12 RS-12 1951–1954 8 B-B Pass 1,200 hp (890 kW) 3 units used in Pass service
BRS15 DRS-4-4-1500 1950 8 B-B Pass 1,500 hp (1,120 kW)
BRS16 AS-616 1953–1955 28 C-C Pass 1,600 hp (1,190 kW) 16 units used in Pass service
BRS24 RT-624 1951–1954 22 C-C Transfer 2,400 hp (1,790 kW)
LRS25 T2500 1950–1951 22 C-C Transfer 2,500 hp (1,860 kW) Built by Lima Locomotive Works

General Electric
See also: List of GE locomotives

PRR Class Builder's Model Build date Total produced Wheel arrangement Service Power output Notes
GS4 44 Ton 1948–1950 46 B-B Switcher 400 hp (300 kW)
GF25 U25B 1965 59 B-B Freight 2,500 hp (1,860 kW)
GF25a U25C 1965 20 C-C Freight 2,500 hp (1,860 kW)
GF28a U28C 1966 15 C-C Freight 2,800 hp (2,090 kW)
GF30a U30C 1967 5 C-C Freight 3,000 hp (2,240 kW)

EMD
See also: List of GM-EMD locomotives.

PRR Class Builder’s Model Build date Total produced Wheel arrangement Service Power output Notes
ES6 SW 1937 12 B-B Switcher 600 hp (450 kW)
ES6 SW1 1942–1950 85 B-B Switcher 600 hp (450 kW)
ES10 NW2 1941–1948 32 B-B Switcher 1,000 hp (750 kW)
ES12 SW7-SW9 1950–1953 84 B-B Switcher 1,200 hp (890 kW)
ES12 SW1200 1957 35 B-B Switcher 1,200 hp (890 kW)
EF15 F3A,F7A 1947–1952 203 B-B Freight 1,500 hp (1,120 kW) Cab A unit
EF15 F3B,F7B 1947–1952 107 B-B Freight 1,500 hp (1,120 kW) Cab B unit
EPF15 FP7A 1952 40 B-B Pass 1,500 hp (1,120 kW) Cab A unit
EPF15 FP7B 1952 14 B-B Pass 1,500 hp (1,120 kW) Cab B unit
EP20 E7A 1945–1949 46 A1A-A1A Pass 2,000 hp (1,490 kW) Cab A unit
EP20 E7B 1945–1949 14 A1A-A1A Pass 2,000 hp (1,490 kW) Cab B unit
EP22 E8A 1950–1952 74 A1A-A1A Pass 2,250 hp (1,680 kW) Cab A unit
ERS15 GP7 1952–1953 66 B-B Freight 1,500 hp (1,120 kW) 10 units used in Pass service
ERS15ax SD7 1953 2 B-B Freight 1,500 hp (1,120 kW)
ERS17 GP9 1955–1959 310 B-B Freight 1,750 hp (1,300 kW) 40 units no cab
ERS17a SD9 1957–1958 25 C-C Freight 1,750 hp (1,300 kW)
EF22 GP30 1963 52 B-B Freight 2,250 hp (1,680 kW)
EF25 GP35 1964–1965 119 B-B Freight 2,500 hp (1,860 kW)
EF25a SD35 1965 40 C-C Freight 2,500 hp (1,860 kW)
EF30a SD40 1966 65 C-C Freight 3,000 hp (2,240 kW)
EF36 SD45 1966 65 C-C Freight 3,600 hp (2,680 kW)
EF20a GP38 1967 5 B-B Freight 2,000 hp (1,490 kW) Built for PRSL

Fairbanks-Morse
See also: List of Fairbanks-Morse locomotives

PRR Class Builder’s Model Build date Total produced Wheel arrangement Service Power output Notes
FS10 H10-44 1948–1949 55 B-B Switcher 1,000 hp (750 kW)
FS12 H12-44 1952–1954 16 B-B Switcher 1,200 hp (890 kW)
FF20 Erie Built 1947–1948 36 A1A-A1A Freight 2,000 hp (1,490 kW) Cab A
FF20 Erie Built 1947–1948 12 A1A-A1A Freight 2,000 hp (1,490 kW) Cab B
FF16 CF-16-4 1950 16 B-B Freight 1,600 hp (1,190 kW) Cab A
FF16 CF-16-4 1950 8 B-B Freight 1,600 hp (1,190 kW) Cab B
FRS-16 H16-44 1952 10 B-B Freight 1,600 hp (1,190 kW)
FRS-20 H20-44 1948–1951 38 B-B Freight 2,000 hp (1,490 kW)
FRS-24 H24-66 1953–1954 9 C-C Freight 2,400 hp (1,790 kW) aka Train Master

See Also:

PRR Modern Power for Today's Trains (1949)

Pennsylvania Railroad

Altoona Works

Locomotives

Steam Locomotives

Diesel-Electric Locomotives

Electric Locomotives

Locomotive Builders