EMD E-unit
Encyclopedia
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...
s built by the General Motors Electro-Motive Division (EMD) and its predecessor the Electro-Motive Corporation (EMC). Final assembly for all E-units was in La Grange, Illinois
La Grange, Illinois
La Grange, a suburb of Chicago, is a village in Cook County, in the U.S. state of Illinois. The population was 15,608 at the 2000 census.-History:...
. Production ran from May, 1937, to December, 1963. The name E-units refers to the model numbers given to each successive type, which all began with E. The E originally stood for eighteen hundred horsepower (1300 kW), the power output of the earliest model, but the letter was kept for later models of far higher power ratings.
The predecessors of the E-units were the EMC 1800 hp B-B locomotives built in 1935. These had similar power and mechanical layouts to the E-units, but enclosed in boxcab
Boxcab
A boxcab, in railroad terminology, is a locomotive in which the machinery and crew areas are enclosed in a box-like superstructure . It is a term mostly used in North America while in Victoria , such locomotives have been nicknamed "butterboxes"...
bodies and with AAR type B two-axle trucks.
EMC also introduced the TA model in 1937, selling six to the Rock Island
Chicago, Rock Island and Pacific Railroad
The Chicago, Rock Island and Pacific Railroad was a Class I railroad in the United States. It was also known as the Rock Island Line, or, in its final years, The Rock.-Incorporation:...
. This had very similar carbody styling, but otherwise had more in common with UP
Union Pacific Railroad
The Union Pacific Railroad , headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman....
M-10001
M-10001
The Union Pacific Railroad's M-10001 was a record breaking diesel-electric streamliner train built in late 1934 by Pullman-Standard with an engine from General Motors Electro-Motive Corporation and General Electric generator, control equipment and traction motors...
, M-10002
M-10002
The Union Pacific Railroad's M-10002 was a diesel-electric streamliner train built in 1936 by Pullman-Standard with a prime mover from the Winton engine division of General Motors Corporation and General Electric generator, control equipment and traction motors...
, and M-10003 through M-10007, in that it was a 1,200 hp (900 kW), single-engined unit on B-B trucks instead of the E-units' A1A-A1A wheel arrangement
Wheel arrangement
In rail transport, a wheel arrangement is a system of classifying the way in which wheels are distributed beneath a locomotive.. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and connections, with the adopted notations varying by country...
. It is therefore not part of the E-unit series.
Like many early passenger locomotives, E-units used two engines to achieve the rated power. This was due to the technology of the time limiting the power that could be developed by a single engine. Even so, while E-units were used singly for shorter trains, longer trains needed multiple locomotive units; many railroads used triple units. E-units could be purchased either with or without driving cabs; units with a cab are called A unit
A unit
An A unit, in railroad terminology, is a locomotive equipped with a driving cab, or crew compartment, and the control system to control other locomotives in a multiple unit, and therefore able to be the lead unit in a consist of several locomotives controlled from a single position...
s or lead units, while cabless units are called B unit
B unit
A "B" unit, in railroad terminology, is a locomotive unit which does not have a driving cab, or crew compartment, and must therefore be controlled from another, coupled locomotive with a driving cab . The term booster unit is also used. The concept was largely confined to North America...
s or booster units. B units did contain simple controls for hostling purposes, but they could not be so controlled on the main line. The locomotive units were linked together with MU cables which enabled the crew in the lead unit at the front to control the trailing units. Railroads tended to buy either ABA sets (two driving cab-equipped units facing in opposite directions with a booster in between) or ABB sets (a single driving cab with a pair of boosters). The former did not need to be turned to pull in either direction, but B units were cheaper than A units and they made for a smoother line to the train.
Styling
The EA and E1 had sloping noses with recessed headlights, while the E2 had a more bulbous "bulldog" noseBulldog nose
"Bulldog nose" is the nickname given, due to their appearance, to several diesel locomotives manufactured by GM-EMD and its licencees from 1939 to 1970...
. Models E3 through E6 had a sloping nose but with a protruding headlight, while models E7 through E9 used a less sloped (closer to vertical) style like the freight F-units. A patent of 1937 signed by several EMC engineers defined the styling.
Many older E-units were updated to newer styles. The E8 introduced the one-piece stamped Farr stainless-steel side grilles that made a continuous band from front to rear just below the roof, but these were often retrofitted to earlier units. Side windows were half-rounded on the EA/EB, square on the E1, round on the E2, square on most E3 through E7 units, and rounded portholes again on the E8 and E9, but again many railroads updated older locomotives.
The E5 units were unique, produced for the Chicago, Burlington and Quincy Railroad
Chicago, Burlington and Quincy Railroad
The Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwestern United States. Commonly referred to as the Burlington or as the Q, the Burlington Route served a large area, including extensive trackage in the states of Colorado, Illinois, Iowa, Kentucky, Missouri,...
in all stainless steel with fluted lower carbody sides, to match the railroad's Zephyr passenger trains.
Engines
While there were some cosmetic differences between E-unit models, the major line of development was technological, and largely that of increasing power. For example, the first model in the series, the EA/EB, was rated at 1800 hp (1300 kW). An intermediate unit, the E3, was rated at 2,000 hp. The last unit in the series, the E9, was rated at 2,400 hp (1800 kW). This enabled heavier trains to be pulled by the same number of locomotives, or the same weight of train could be pulled faster.Early models (EA/EB through E2) used the Winton
Winton Motor Carriage Company
The Winton Motor Carriage Company was a pioneer United States automobile manufacturer based in Cleveland, Ohio. Winton was one of the first American companies to sell a motor car.-1896:...
201-A engine that had been purchased by Electro-Motive Corporation, the immediate ancestor of the Electro-Motive Division of General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
. This engine was originally designed for submarine use, and wasn't well suited to the sustained full throttle operation often demanded in railroad service (especially in mountain operation). It was not unusual for heavy repairs to be done en route on one non-functioning engine while the other engine propelled the train at reduced speed. The 201-A engines used in E-units were 900 hp (700 kW) V12
V12 engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft....
units.
Models E3 through E9 used the EMD model 567 engine, named after its engine displacement
Engine displacement
Engine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre to bottom dead centre . It is commonly specified in cubic centimeters , litres , or cubic inches...
in cubic inch
Cubic inch
The cubic inch is a unit of measurement for volume in the Imperial units and United States customary units systems. It is the volume of a cube with each of its 3 sides being one inch long....
es per cylinder. Although similar in some ways to the earlier Winton design, the 567 model had been developed by EMD specifically for locomotive use, and exhibited excellent performance and reliability in high speed passenger train service. The 567 had a greater displacement per cylinder than the 201-A and ran at a higher maximum rpm
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...
, elements which when combined gave greater engine output. The 12V-567 V12
V12 engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft....
model used in the E3 through E6 developed 1000 hp (750 kW). The E7 model used the 12V-567A rated at 1000 hp (750 kW). The E8 used the more advanced 567B unit, with improved exhaust manifolds and other enhancements to give 1,125 hp each. More development resulted in the 1200 hp (900 kW) 567C engine used in the E9.
Other changes
Other improvements occurred independently of the change in engine design. The E8, for example, was the first model to incorporate electric cooling fans, and offer dynamic brakingDynamic braking
Dynamic braking is the use of the electric traction motors of a railroad vehicle as generators when slowing the Locomotive. It is termed rheostatic if the generated electrical power is dissipated as heat in brake grid resistors, and regenerative if the power is returned to the supply line...
as an option.
Trucks
All E-units used the same EMD passenger truckBogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
design by engineer Martin Blomberg. This was an A1A-A1A truck, with the outside axles powered and the inner axle unpowered. Like the well-known two-axle Blomberg B
Blomberg B
The Blomberg B was a "B" diesel locomotive truck. These trucks were the standard EMD four wheel truck from the FT up until the GP60. EMD introduced the truck in 1936. Unofficially it is named after Martin Blomberg, who joined the company the year before...
trucks, these trucks featured outside spring hangers between the wheels for better cushioning of side-to-side motion. Also like the Blomberg B, there were no drop equalizers between the axles. The success of the design is demonstrated by the remarkably few changes to it over the years.
Complete list of models
- EA/EB - for B&OBaltimore and Ohio RailroadThe Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...
; 6 A units and 6 B units constructed. - E1 - for ATSFAtchison, Topeka and Santa Fe RailwayThe Atchison, Topeka and Santa Fe Railway , often abbreviated as Santa Fe, was one of the larger railroads in the United States. The company was first chartered in February 1859...
; 8 A units and 3 B units. - E2 - for jointly owned and run UPUnion Pacific RailroadThe Union Pacific Railroad , headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman....
, C&NWChicago and North Western RailwayThe Chicago and North Western Transportation Company was a Class I railroad in the Midwest United States. It was also known as the North Western. The railroad operated more than of track as of the turn of the 20th century, and over of track in seven states before retrenchment in the late 1970s...
, and SP trains City of San Francisco, City of Los Angeles. 2 A units, 4 B units. - E3 - Total of 17 A units plus 2 B units built, for ATSF (1 A, 1 B), ACLAtlantic Coast Line RailroadThe Atlantic Coast Line Railroad was an American railroad that existed between 1900 and 1967, when it merged with the Seaboard Air Line Railroad, its long-time rival, to form the Seaboard Coast Line Railroad...
(2 A), RIChicago, Rock Island and Pacific RailroadThe Chicago, Rock Island and Pacific Railroad was a Class I railroad in the United States. It was also known as the Rock Island Line, or, in its final years, The Rock.-Incorporation:...
(2 A), FEC (2 A), KCS (2 A, + ex EMC demonstrator A), C&NW (4 A), MPMissouri Pacific RailroadThe Missouri Pacific Railroad , also known as the MoPac, was one of the first railroads in the United States west of the Mississippi River. MoPac was a Class I railroad growing from dozens of predecessors and mergers, including the St. Louis, Iron Mountain and Southern Railway , Texas and Pacific...
(2 A), and UP (1 A, 1 B). - E4 - for SAL; 14 A units, 5 B units constructed.
- E5EMD E5The EMD E5 was a , A1A-A1A passenger train-hauling diesel locomotive manufactured by Electro-Motive Corporation, and its corporate successor, General Motors' Electro-Motive Division of La Grange, Illinois, and produced exclusively for the Chicago, Burlington and Quincy Railroad , and its...
- for the BurlingtonChicago, Burlington and Quincy RailroadThe Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwestern United States. Commonly referred to as the Burlington or as the Q, the Burlington Route served a large area, including extensive trackage in the states of Colorado, Illinois, Iowa, Kentucky, Missouri,...
; 11 A units and 5 B units constructed. - E6EMD E6The EMD E6 was a , A1A-A1A, passenger train locomotive manufactured by Electro-Motive Corporation, and its corporate successor, General Motors Electro-Motive Division, of La Grange, Illinois. The cab version, or E6A, was manufactured from November, 1939 to September, 1942, and 91 were produced...
- 91 A units and 26 B units built. - E7EMD E7The EMD E7 was a , A1A-A1A passenger train locomotive manufactured by General Motors' Electro-Motive Division of La Grange, Illinois. The cab version, or E7A, was manufactured from February, 1945 to April, 1949, and 428 were produced. The booster version, or E7B, was manufactured from March, 1945...
- 428 A units and 82 B units built. - E8EMD E8The EMD E8 was a , A1A-A1A passenger train locomotive manufactured by General Motors' Electro-Motive Division of La Grange, Illinois. The cab version, or E8A, was manufactured from August, 1949 to December, 1953, and 449 were produced – 446 for U.S., and 3 for Canada...
- 449 A units and 46 B units built. - E9EMD E9The EMD E9 was a , A1A-A1A passenger train-hauling diesel locomotive built by General Motors' Electro-Motive Division of La Grange, Illinois between April 1954 and January 1964. 100 cab-equipped lead A units were produced, along with 44 cabless booster B units. All were for service within the...
- 100 A units and 44 B units built.
Oddities
- AB6 - Two B unitB unitA "B" unit, in railroad terminology, is a locomotive unit which does not have a driving cab, or crew compartment, and must therefore be controlled from another, coupled locomotive with a driving cab . The term booster unit is also used. The concept was largely confined to North America...
s built with a flat-fronted driving cab for the Chicago, Rock Island and Pacific RailroadChicago, Rock Island and Pacific RailroadThe Chicago, Rock Island and Pacific Railroad was a Class I railroad in the United States. It was also known as the Rock Island Line, or, in its final years, The Rock.-Incorporation:...
. These were used to take one portion of a train onward to a side destination while the rest of the train continued onward. - AA - half an E6, with a single 1,000 hp (750 kW) engine and a baggage compartment where the rear engine would have been. One unit built for Missouri Pacific.
- CNW E9BS Crandall cab - E9 B units converted to A units by the Chicago and North Western RailwayChicago and North Western RailwayThe Chicago and North Western Transportation Company was a Class I railroad in the Midwest United States. It was also known as the North Western. The railroad operated more than of track as of the turn of the 20th century, and over of track in seven states before retrenchment in the late 1970s...
, with a squarish cab built in the railroad's own shop in Oelwein.