The AAR wheel arrangement system is a method of classifying locomotive (or unit) wheel arrangements that was developed by the Association of American Railroads. It is essentially a simplification of the European UIC classification, and it is widely used in North America to describe diesel and electric locomotives. It is not used for steam locomotives; instead, the Whyte notation is used. This system counts axles instead of wheels. Letters refer to powered axles, and numbers to unpowered (or idler) axles. "A" refers to one powered axle, "B" to two powered axles in a row, "C" to three powered axles in a row, and "D" to four powered axles in a row. "1" refers to one idler axle, and "2" to two idler axles in a row. A dash ("–") separates trucks, or wheel assemblies. A plus sign ("+") refers to articulation. Categories: Organization stubs | Rail transport | Industry trade groups ... The UIC classification is a comprehensive system for describing the wheel arrangements of locomotives. ... World map showing North America A satellite composite image of North America North America is a continent in the northern hemisphere bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the... Great Western Railway No. ... East German E 18 electric locomotives of the Deutsche Reichsbahn An electric locomotive is a locomotive powered by electric motors which draws current from an overhead wire, a third rail, or an on-board storage device such as a battery or a flywheel energy storage system. ... Great Western Railway No. ... A selection of early 20th century locomotive types according to their Whyte notation and their comparative size The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early 20th century. ... A bogie is a wheeled wagon or trolley. ...

A1A-2

"A1A-2" means there are two trucks, or wheel assemblies. The "A1A" truck is under the front of the unit, and has one powered axle, one idler axle, and one more powered axle. The "2" truck is under the back of the unit, and has two idler axles in a row. The only documented example is the FM OP800 800 hp railcar, six of which were built by the St. Louis Car Company exclusively for the Southern Railway in 1939. Retired Georgia Northern Railway #2, a Fairbanks-Morse Model OP800 railcar, sits in storage in Moultrie, Georgia in 1967. ... The St. ... The Southern Railway (AAR designation SOU) was the product of nearly 150 predecessor lines that were combined, reorganized and recombined since the 1830s. ...

A1A-3

"A1A-3" means there are two trucks, or wheel assemblies. The "A1A" truck is under the front of the unit, and has one powered axle, one idler axle, and one more powered axle. The "3" truck is under the back of the unit, and has three idler axles in a row. An example is the Baldwin DR-6-2-10 1,000 hp cab unit, only one of which was built for the Chicago and North Western Railway in 1948. Baldwin Locomotive Works produced several different Baldwin DR-6 models of 6-axle passenger train-hauling diesel locomotives between 1945 and 1948. ... The Chicago and North Western Railway (AAR reporting marks: CNW, CNWS, CNWZ; unofficial abbreviation: C&NW) was a Class I railroad in the United States. ...

==A1A-A1A== "A1A-A1A" means there are two identical trucks, or wheel assemblies under the unit. Each truck has one powered axle, one idler axle, and one more powered axle. This was to more evenly spread the weight of the locomotive over the track. Examples include the EMD E-units and ALCO PAs, which were passenger locomotives, and the dual service FM Erie-built. Image File history File links Example. ... Categories: Stub | EMD locomotives ... A PA-1 hauled the American Freedom Train of 1946. ... Back-to-back Erie-built cab units lead the Milwaukee Roads Olympian Hiawatha passenger train through Butte, Montana in June, 1949. ...

B

"B" means there are two powered axles under the unit. These axles are not articulated relative to other parts of the locomotive. This arrangement is only used on very small locomotives.

B-1

"B-1" means there are two trucks, or wheel assemblies. The "B" truck is under the front of the unit, and has two powered axles. The "1" truck is under the back of the unit, and has one idler axle. Examples include the three EMD LWT12 Aerotrain locomotives built by EMD in 1956. For the hovercraft train developed in France from 1965 to 1975, see Aérotrain. ... The Aerotrain is a streamlined trainset built by General Motors Electro-Motive Division. ... Electro-Motive Diesels, Inc. ... 1956 (MCMLVI) was a leap year starting on Sunday of the Gregorian calendar. ...

B-2

"B-2" means there are two trucks, or wheel assemblies. The "B" truck is under the front of the unit, and has two powered axles. The "2" truck is under the back of the unit, and has two idler axles in a row. Examples include the three lightweight locomotives built by Baldwin in 1956 and 1957 for use with Pullman-Standard Train X equipment. Baldwin Locomotive Works builders plate, 1922 The Baldwin Locomotive Works was an American builder of railroad locomotives. ... 1956 (MCMLVI) was a leap year starting on Sunday of the Gregorian calendar. ... 1957 (MCMLVII) was a common year starting on Tuesday of the Gregorian calendar. ... The Pullman Palace Car Company, owned by George Pullman, manufactured railroad cars in the mid to late 1800s through the early decades of the 20th century, during the boom of railroads in the United States. ...

B-A1A

"B-A1A" means there are two trucks, or wheel assemblies. The "B" truck is under the front of the unit, and has two powered axles. The "A1A" truck is under the back of the unit, and has one powered axle, one idler axle, and one more powered axle. Examples include the FM C-liners (most passenger units) built from 1950–1955, and the EMD FL9. Canadian Locomotive Company #4105, a Fairbanks-Morse Model CPA-16-4 C-liner decked out in Canadian Pacific Railway livery. ... 1950 (MCML) was a common year starting on Sunday (link will take you to calendar). ... 1955 (MCMLV) was a common year starting on Saturday of the Gregorian calendar. ... ConnDOT FL9 #2027 in a New Haven paint scheme The EMD FL9 (New Haven Class EDER-5) was an Electric-Diesel-electric dual-power locomotive, capable of self-powered diesel-electric operation and of operation as an electric locomotive powered from a third rail. ...

B-B

"B-B" means there are two identical trucks, or wheel assemblies under the unit. Each truck has two powered axles, a currently-popular configuration used in high-speed, low-weight applications, such as intermodal trains. Examples include the EMD GP (General Purpose) units. The following is a list of locomotives produced by the General Motors Electro-Motive Division (GM-EMD). ...

B-B-B

"B-B-B" means there are three identical trucks, or wheel assemblies under the unit. Each truck has two powered axles. This arrangement is unusual. Placing six axles in a C-C arrangement is far more common. The EMD GM10 electric locomotive used this arrangement. General Motors Electro-Motive Division (normally shortened to GM EMD or just EMD) is the worlds largest builder of railroad locomotives. ...

2-B+B-2

"2-B+B-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are two powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The PRR DD1 and DD2 electric locomotives used this arrangement. PRR DD1 locomotive. ... The Pennsylvania Railroads class DD2 electric locomotive was a single prototype locomotive never placed into series production. ... East German E 18 electric locomotives of the Deutsche Reichsbahn An electric locomotive is a locomotive powered by electric motors which draws current from an overhead wire, a third rail, or an on-board storage device such as a battery or a flywheel energy storage system. ...

B+B-B+B

"B+B-B+B" means there are four identical trucks, or wheel assemblies under the unit. Within each truck, there are two powered axles, and pairs of them are connected by span bolsters. An example would be the General Electric U50, built from 1963-1965. The 4500 horsepower (3.4 MW) turbine locomotives built by GE for Union Pacific also used this arrangement. The EVFM railway of Brazil uses narrow gauge GE "BB" locomotives with this arrangement, both with "standard" and wide cabs. A GE BB40-9W, for instance, is a wide cab Dash 9 series 4000 hp locomotive with a B+B-B+B wheel arrangement. A span bolster, in rail terminology, is a beam or frame used to link two trucks (US) or bogies (UK) so that they can be articulated together and be joined to the locomotive or railroad car at one rotating mounting point. ... U50 #50 on an eastbound freight at Laramie, Wyoming. ... 1963 (MCMLXIII) was a common year starting on Tuesday (link will take you to calendar). ... 1965 (MCMLXV) was a common year starting on Friday (link goes to calendar). ... Ge or GE may stand for: Ge, a letter of Cyrillic alphabet Gaia, (Ge) short form Ge is also an American Indian tribe from Eastern and Southern Amazon General Electric (GE). ... The Union Pacific Railroad (NYSE: UNP) is the largest railroad in the United States. ... Narrow-gauge railways are railroads (railways) with track spaced at less than the standard gauge of 4 ft 8 in (1. ...

B-B+B-B

"B-B+B-B" means that the locomotive has four identical trucks, or wheel assemblies. Each truck contains two powered axles. The middle pair of trucks are connected by a span bolster. In most cases the locomotive is articulated over the span bolster. The Union Pacific's M-10002 is an example of this type. This arrangement also includes locomotives made of two permanently coupled B-B units, such as some EMD FT units which had a solid drawbar connecting two units instead of the typical couplers. A span bolster, in rail terminology, is a beam or frame used to link two trucks (US) or bogies (UK) so that they can be articulated together and be joined to the locomotive or railroad car at one rotating mounting point. ... The Union Pacific Railroad (NYSE: UNP) is the largest railroad in the United States. ... The M-10002 at Cheyenne, Wyoming. ... EMD FT - Wikipedia, the free encyclopedia /**/ @import /skins-1. ...

C

"C" means there are three powered axles under the unit. They are not articulated relative to other parts of the locomotive. This arrangement is only used on very small locomotives.

C-C

"C-C" means there are two identical trucks, or wheel assemblies under the unit. Each truck has three powered axles. Examples include the EMD SD (Special Duty) units. This is a currently popular configuration used in low-speed, high-weight applications, such as unit coal trains. The following is a list of locomotives produced by the General Motors Electro-Motive Division (GM-EMD). ...

1-C+C-1

"1-C+C-1" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with one idler axle, and inboard of it are three powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The PRR FF1 and FF2 electric locomotives used this arrangement. Big Liz, the sole FF1. ... The Pennsylvania Railroads class FF2 electric locomotives comprised eight boxcab units purchased from the Great Northern Railway in 1956 following the GNs dismantling of its Cascade Tunnel [electrification]]. Their GN classifications were Y1 and Y1a. ...

2-C+C-2

"2-C+C-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are three powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The GG1 electric locomotives and GE steam turbine-electric locomotives used this arrangement. PRR GG1 number 4890 on display at the National Railroad Museum in Green Bay, WI. The Pennsylvania Railroads GG1 class of electric locomotives were built between 1934 to 1943, with a total of 139 units constructed. ... Ge or GE may stand for: Ge, a letter of Cyrillic alphabet Gaia, (Ge) short form Ge is also an American Indian tribe from Eastern and Southern Amazon General Electric (GE). ... A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. ...

C-C+C-C

"C-C+C-C" means there are four identical trucks, or wheel assemblies under the unit. Each truck has three powered axles. The only examples of this type were the 8500 horsepower (6.3 MW) turbine locomotives built by General Electric for Union Pacific. These locomotives consisted of two permanently-coupled C-C units. A gas turbine-electric locomotive, or GTEL, is a locomotive that uses a gas turbine as a prime mover to drive an electric generator or alternator. ... The General Electric Company, or GE (NYSE: GE) is a multinational technology and services company. ... The Union Pacific Railroad (NYSE: UNP) is the largest railroad in the United States. ...

C+C-C+C

"C+C-C+C" means there are four identical trucks, or wheel assemblies under the unit. Each truck has three powered axles and pairs of them are connected by span bolsters. This arrangement was used on the "Jawn Henry" steam turbine-electric locomotive. A span bolster, in rail terminology, is a beam or frame used to link two trucks (US) or bogies (UK) so that they can be articulated together and be joined to the locomotive or railroad car at one rotating mounting point. ...

2-D-2

"2-D-2" means there are three trucks, or wheel assemblies under the unit. At either end are trucks with two idler axles; the center truck has four powered axles. The PRR R1 electric locomotive used this arrangement. 1911 map The Pennsylvania Railroad (AAR reporting mark PRR) was an American railroad existing 1846–1968, after which it merged into Penn Central Transportation. ... Pennsylvania Railroad class R1 comprised a single prototype electric locomotive of 4-8-4 wheel arrangement in the Whyte notation, 2-D-2 in the AAR standards and 2Do2 in the UIC classification. ...

D-D

"D-D" means there are two identical trucks, or wheel assemblies under the unit. Each truck has four powered axles. Examples include the EMD DD units. The following is a list of locomotives produced by the General Motors Electro-Motive Division (GM-EMD). ...

2-D+D-2

"2-D+D-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. Examples include the Baldwin DR-12-8-1500/2 "Centipede" diesel locomotives and the GE Little Joe electric locomotives. Baldwin Locomotive Works builders plate, 1922 The Baldwin Locomotive Works was an American builder of railroad locomotives. ... A Centipede pair on the Pennsylvania Railroad. ... Great Western Railway No. ... Ge or GE may stand for: Ge, a letter of Cyrillic alphabet Gaia, (Ge) short form Ge is also an American Indian tribe from Eastern and Southern Amazon General Electric (GE). ... A Little Joe preserved at Illinois Railway Museum. ... East German E 18 electric locomotives of the Deutsche Reichsbahn An electric locomotive is a locomotive powered by electric motors which draws current from an overhead wire, a third rail, or an on-board storage device such as a battery or a flywheel energy storage system. ...

B-D+D-B

"B-D+D-B" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two powered axles, and inboard of it are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The W1 class of electric locomotives built by General Electric for the Great Northern used this arrangement. Great Northern may refer to: the Great Northern Diver, Gavia adamsii, a bird the Great Northern War, a war fought by Russia, Denmark-Norway, and Saxony-Poland against Sweden the Great Northern Railway, an Irish railway the Great Northern Railway, a United States railroad the Great Northern Railway, a British...

1B-D+D-B1

"1B-D+D-B1" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with one unpowered axle and two powered axles, and inboard of there are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The "Bi-Polar" electric locomotives used by the Milwaukee Road used this arrangement. The Milwaukee Road, officially the Chicago, Milwaukee, St. ...

References

• Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide, Kalmbach Publishing Co., Milwaukee, WI. ISBN 0-89024-026-4.