![The street railway review (1891) (14779577373)](https://upload.wikimedia.org/wikipedia/commons/8/84/The_street_railway_review_%281891%29_%2814779577373%29.jpg)
Rigid-framed electric locomotives were some of the first generations of
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 ...
design. When these began the
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 ...
s of these early locomotives, particularly with AC motors, were too large and heavy to be mounted directly to the axles and so were carried on the frame. One of the initial simplest wheel arrangements for a mainline electric locomotive, from around 1900, was the
1′C1′ arrangement, in
UIC classification
The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...
.
Some of these locomotives had their driving wheels coupled with
coupling rod
A coupling rod or side rod connects the driving wheels of a locomotive. Steam locomotives in particular usually have them, but some diesel and electric locomotives, especially older ones and shunters, also have them. The coupling rods transfer t ...
s, as for steam locomotives. Others had individual motors for each axle, as would later become universal.
By the middle of the century, the bogie arrangement for locomotives became more popular and rigid-framed locomotives are now rare, except for small shunters.
1′C1′
![WheelArrangement 2-6-2](https://upload.wikimedia.org/wikipedia/commons/d/d4/WheelArrangement_2-6-2.svg)
1′C1′ is the
UIC classification
The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...
for a
railway locomotive
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the us ...
with a
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 ...
of three coupled driving wheels, with a leading and trailing articulated
pony truck
A Bissell or Bissel truck (also Bissel bogie or Pony truck) is a single-axle bogie which pivots towards the centre of a steam locomotive to enable it to negotiate curves more easily. Invented in 1857 by and usually then known as a ''pony truck' ...
. The driving wheels are coupled by external
coupling rod
A coupling rod or side rod connects the driving wheels of a locomotive. Steam locomotives in particular usually have them, but some diesel and electric locomotives, especially older ones and shunters, also have them. The coupling rods transfer t ...
s.
The description is most commonly applied to some locomotives from the early decades of
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 ...
design, when the
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 ...
or motors were mounted on a rigid frame and drove all the driving wheels coupled together. To permit higher speeds for fast passenger services, leading pony trucks were added. An advantage of electric locomotives was that they could easily have two driver's cabs, so avoiding the need to turn them at
terminus station
A train station, railway station, railroad station or depot is a railway facility where trains stop to load or unload passengers, freight or both. It generally consists of at least one platform, one track and a station building providing such ...
s and so the wheel arrangement was made symmetrical to run equally well in both directions.
Steam locomotives
![BT-Eb-3-5Nr9](https://upload.wikimedia.org/wikipedia/commons/0/06/BT-Eb-3-5Nr9.jpg)
The equivalent
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 major ...
or
2-6-2T
T, or t, is the twentieth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''tee'' (pronounced ), plural ''tees''. It is deri ...
''Prairie'' arrangement for
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, oil or, rarely, wood) to heat water in the locomot ...
s was a popular one for a long period. The first was the South African
Cape Government Railways 2nd Class 2-6-2TT of 1875. Building of 2-6-2T classes, such as the
GWR ''Prairies'' or
Standard Class 2s, continued almost to
the end of steam.
Many of these prairies were
tank engine
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of a more traditional tender. Most tank engines also have bunkers (or fuel tanks) to hold fuel; in a tender-tank locomot ...
s, which were able to run equally well in either direction. This was aided by the symmetry of the wheel arrangement. These were often used for suburban passenger services, which needed fast turnarounds at city terminus stations, without needing to turn the locomotive on a
turntable
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. Although quite powerful locomotives were used, to give good acceleration between closely spaced stations, they did not need the sustained speed or fuel capacity of an express locomotive.
Electric locomotives
Italy
![288](https://upload.wikimedia.org/wikipedia/commons/6/6c/288._%271904%27_Valtellina_locomotive.jpg)
This first 1′C1′ arrangement was only a common one for electric locomotives in the early years. It was used for some early AC examples, mostly Italian, between 1900 and 1920. Italian railways had begun electrification with a
low-frequency three-phase AC system, to the designs of the Hungarian
Kálmán Kandó
Kálmán Kandó de Egerfarmos et Sztregova (''egerfarmosi és sztregovai Kandó Kálmán''; 10 July 1869 – 13 January 1931) was a Hungarian engineer, the inventor of phase converter and a pioneer in the development of AC electric railway tract ...
. These used large, 2 metre diameter, motors, powerful enough that only one or two motors were needed for the locomotive, but also too large diameter to be mounted easily for a drive to the axle. Accordingly, Kandó frame mounted the motors on resilient springs and used
coupling rod
A coupling rod or side rod connects the driving wheels of a locomotive. Steam locomotives in particular usually have them, but some diesel and electric locomotives, especially older ones and shunters, also have them. The coupling rods transfer t ...
drives to the wheels.
The first of these locomotives were the Italian RA 361, later
FS Class E.360
The FS Class E.360 were electric locomotives of the Italian State Railways (FS), using three-phase alternating current, built for the operation of the Valtellina line. They were ordered by Rete Adriatica (the Adriatic Network) and were origi ...
, for the 1902 electrification of the
Valtellina line.
For these early small locomotives, the power was sufficiently low that both motors could be coupled to the crankpin of the centre axle with a simple rigid triangular coupling rod. Secondary rods carried the drive to the other wheels. The motors were rigidly mounted to the frames and so the centre crankpin had a vertical slide mechanism in the triangular rod, for suspension travel. Each of these two motors were rated at 600 bhp and weighed 8.2 metric tons, 40% of the total weight of the locomotive.
France
![Deri Repulsion Type Motor Midi E 3301](https://upload.wikimedia.org/wikipedia/commons/1/1a/Deri_Repulsion_Type_Motor_Midi_E_3301.png)
The 1′C1′ arrangement was considered as something of a standard pattern for small passenger locomotives, so that when the French
Chemins de fer du Midi
The Compagnie des chemins de fer du Midi (. CF du Midi), also known in English as the Midi or Southern Railway, was an early French railway company which operated a network of routes in the southwest of the country, chiefly in the area between ...
electrified at 12 kV 16â…” Hz AC in 1912, six locomotives of this type were ordered for trials, from the major electric locomotive makers of Europe: E 3001, E 3101,
E 3201,
E 3301, E 3401, E 3501. Only E 3201, built by the American
Westinghouse, was considered successful and it lasted in service under the
SNCF
The Société nationale des chemins de fer français (; abbreviated as SNCF ; French for "National society of French railroads") is France's national state-owned railway company. Founded in 1938, it operates the country's national rail traffi ...
as 1C1 3900 until 1959. E 3401, by
Jeumont
Jeumont () is a commune in the Nord department in northern France. It lies on the Belgian border and on the river Sambre, adjacent to the Belgian town Erquelinnes. It is part of the agglomeration (''unité urbaine'') of Maubeuge.
Population
E ...
, used the 1′Co1′ layout, with separate motors for each axle.
When the production locomotives from these prototypes were to be built, they were to follow the Westinghouse design of E 3201 but they were so delayed by the war that when they emerged as
2C2 3100
The 2C2 3100 were a class of electric locomotives of the Chemins de fer du Midi, France. They were ordered in 1914 but, because of the First World War, deliveries did not begin until 1923. They were designed for alternating current at 12 kV, 16â ...
they had become a
2′C2′ design with bogies instead of pony trucks and with three vertically mounted motors by
Dick, Kerr of Britain, not Westinghouse.
Sweden
![SJ D near Gävle](https://upload.wikimedia.org/wikipedia/commons/0/04/SJ_D_near_G%C3%A4vle.jpg)
Some of the last 1′C1′ locomotives in service were the Swedish
SJ D
D is a series of locomotives used by Swedish State Railways ( sv, Statens Järnvägar, SJ). 333 units were built by ASEA between 1925-43. It was used for both passenger and freight trains until it was taken out of service in 1988.
History
Though ...
and
Da classes. The D class were built from 1925 to 1943 in several sub-variants and a modernised version, the Da, in the mid 1950s. Both remained in service until around 1990. Both had a pair of traction motors, up to for the Da, and retained the coupling rod drive. The motors were geared to a single
jackshaft
A jackshaft, also called a ''countershaft'', is a common mechanical design component used to transfer or synchronize rotational force in a machine. A jackshaft is often just a short stub with supporting bearings on the ends and two pulleys, gear ...
placed level with the other axles, in the position where a third equi-spaced axle would have been, and so did not require the complicated or heavy triangular drives of earlier designs.
Diesel locomotives
1′C1′ was not generally used for diesel locomotives. The overlap between viable diesel locomotives, owing to the development of the first
high-speed diesel engine
High Speed or high-speed may refer to:
Films
* ''High Speed'' (1917 film), starring Jack Mulhall and Fritzi Ridgeway
* ''High Speed'' (1920 film), an American drama directed by Charles Miller
* ''High Speed'' (1924 film), featuring Herbert Ra ...
s from around 1930, and the era of small rigid framed driving wheels was short. The first diesel shunting locomotives were of C or 0-6-0 wheel arrangement, as they were neither heavy enough nor fast enough to need the pony trucks. These low-powered shunting locomotives could also make do with a single traction motor.
More powerful mainline locomotives used multiple traction motors, one per axle. This was mostly due to the locomotive's generator being able to produce DC current, thus allowing simpler and more controllable DC motors to be used. These could easily be made in the smaller diameters needed for per-axle use, rather than the large diameter many-pole AC motors. As diesel locomotives developed, the per-axle traction motor design became ubiquitous, with
1′Co1′ and
1′Do1′
Rigid-framed electric locomotives were some of the first generations of electric locomotive design. When these began the traction motors of these early locomotives, particularly with AC motors, were too large and heavy to be mounted directly to the ...
designs in early years, later with bogies as
Bo′Bo′
B-B and Bo-Bo are the Association of American Railroads (AAR) and British classifications of wheel arrangement for railway locomotives with four axles in two individual bogies. They are equivalent to the B′B′ and Bo′Bo′ classifications i ...
, then
Co′Co′ and heavier designs.
A rare exception was the Armstrong Whitworth
hydrostatic drive
Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and ...
locomotive of 1929 for the
Buenos Aires Great Southern Railway
The Buenos Aires Great Southern Railway (BAGS) ( es, Ferrocarril del Sud) was one of the ''Big Four'' Indian gauge, broad gauge, , British-owned companies that built and operated railway networks in Argentina. The company was founded by Edward ...
of
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. This used a single transmission and jackshaft drive from one end, with coupling rods. The locomotive was unsuccessful, owing to problems with the transmission and lay unused for several years before being scrapped in 1943.
1′Co1′
The 1′Co1′ wheel arrangement was similar, except that the wheels were driven by separate
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 ...
s for each axle, rather than them being coupled together. As each axle was driven, there was no longer a need for the coupling rod connection between them. This independence would in time raise the issue of
wheelslip, starting with a single axle, but that was not an issue for the early locomotives, with their low ratios of power to
adhesive weight
Adhesive weight is the weight on the driving wheels of a locomotive, which determines the frictional grip between wheels and rail, and hence the drawbar pull which a locomotive can exert.
See also
*Factor of adhesion
*Tractive effort
As used in ...
.
Diesel-electric locomotive
A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conv ...
s used the 1′Co1′ arrangement with separate traction motors, rather than the coupled 1′C1′. This was because these were some decades later than the first electrics, by which time traction motor technology had developed. Also the generators on board the locomotive could generate DC, rather than AC. Control of DC was more sophisticated by this time and there was no need for the traction motors to be the large diameter that the 1900 AC electrics had required.
The first British mainline diesel locomotive,
Armstrong Whitworth
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomotives, automobiles and a ...
'
800 bhp locomotivebuilt for the
LNER LNER may refer to:
*London and North Eastern Railway, a railway company in the United Kingdom from 1923 until 1947
*London North Eastern Railway, a train operating company in the United Kingdom since 2018
* Liquid neutral earthing resistor, a type ...
in 1933, was of this type.
This locomotive was unsuccessful and scrapped after only a few years, in 1937.
2′C2′
![Locomotiva FS E](https://upload.wikimedia.org/wikipedia/commons/a/a8/Locomotiva_FS_E.332.1.jpg)
In 1914
Italian State Railways
Ferrovie dello Stato Italiane S.p.A. ( "Italian Railways of the State"; previously only Ferrovie dello Stato, hence the abbreviation FS) is Italy's national state-owned railway holding company that manages transport, infrastructure, real estate ...
constructed two series, the
E.331 and
E.332, of three-phase AC locomotives. These were intended to be a development of the 1′C1′
E.330, suitable for lighter secondary lines. The heavy central V coupling rod and closely set paired motors of the E.330 were replaced by two motors set either side of the transformer and control gear, and with a lighter rod drive in order to reduce
hammerblow, using lighter rods and a pair of jackshafts set beyond the coupled wheels. Overall, this reduction in reciprocating mass had the effect of making the overall locomotive heavier and with greater overhang at the ends, requiring bogies rather than pony trucks.
2′Co2′
![North_Eastern_Railway_electric_locomotive_No_13](https://upload.wikimedia.org/wikipedia/commons/a/a0/North_Eastern_Railway_electric_locomotive_No_13.jpg)
After the initial promise of electrification on the Shildon–Newport line coal traffic, the
North Eastern Railway commissioned a large express passenger locomotive, later classed as
EE1. Although the mainline electrification through York never took place, the locomotive itself was a success in its brief trials. The driving wheels were unusually large, following the steam locomotive practice with which
Darlington Works
Darlington Works was established in 1863 by the Stockton and Darlington Railway in the town of Darlington in the north east of England.
The main part of the works, the North Road Shops was located on the northeast side of the Stockton and Darl ...
were more familiar, and the electrical equipment was supplied by
Metropolitan-Vickers
Metropolitan-Vickers, Metrovick, or Metrovicks, was a British heavy electrical engineering company of the early-to-mid 20th century formerly known as British Westinghouse. Highly diversified, it was particularly well known for its industrial el ...
of Manchester. The locomotive was heavy for a DC electric and in consideration of its high design speed, four-wheel bogies were used at each end.
(1′Co1′)+(1′Co1′)
![New Haven EP-2 quill running gear](https://upload.wikimedia.org/wikipedia/commons/d/d6/New_Haven_EP-2_quill_running_gear.jpg)
The American
New Haven EP-2
The New Haven EP-2 was a class of boxcab electric locomotives built by Baldwin-Westinghouse for the New York, New Haven and Hartford Railroad. The locomotives worked passenger trains on the New Haven's electrified division west of New Haven, Conn ...
of 1919–1927 combined two 1′Co1′ sub-frames beneath a single
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 ...
body to make a
(1′Co1′)+(1′Co1′) locomotive. As the two frames were articulated together and the body on top was not a structural component, this was a (1′Co1′)+(1′Co1′) rather than (1′Co1′)(1′Co1′); i.e. articulated in two units, rather than with bogies beneath a singe structure. At 2,000 hp, they were around the same power as a pair of the previous
EP-1s, which had often worked
in multiple, although also lighter and more stable at speed.
The EP-1s had required conversion from a Bo'Bo' arrangement to (1′Bo)(Bo1′), in order to prevent oscillation or 'nosing' when running at speed. The same use of pony trucks was designed into the EP-2 from the outset. The central carrying axles were largely pointless though, having no guiding function. When additional locomotives, the
EP-3 and then
EP-4, were required in the 1930s, these used a
(2′C)+(C2′) arrangement, with the carrying axles moved to the ends as twin-axle bogies.
1′B1′
![SBB Historic - RhB Ge 2-4 cropped](https://upload.wikimedia.org/wikipedia/commons/0/0e/SBB_Historic_-_RhB_Ge_2-4_cropped.jpeg)
The smaller four-driver 1′B1′ layout was not generally used, but the Swiss narrow-gauge
Rhaetian Railway
The Rhaetian Railway (german: Rhätische Bahn; it, Ferrovia retica; rm, Viafier retica), abbreviated RhB, is a Swiss transport company that owns the largest network of all private railway operators in Switzerland. Headquartered in Chur, the RhB ...
did have one class of seven, the
Ge 2/4 in 1912. These were low-frequency AC locomotives with a single
repulsion motor
A repulsion motor is a type of electric motor which runs on alternating current (AC). It was formerly used as a traction motor for electric trains (e.g. SR Class CP and SR Class SL electric multiple units) but has been superseded by other type ...
mounted in the body, driving by rods downwards to a central jackshaft and then to the driving wheels.
1′D1′ and 1′E1′
![PO 1D1 E 21 Ã 25, voyageurs et marchandises, constr 1920 S](https://upload.wikimedia.org/wikipedia/commons/2/2e/PO_1D1_E_21_%C3%A0_25%2C_voyageurs_et_marchandises%2C_constr_1920_S.L.M.Winterthur_%26_Brown-Bovery.jpg)
Larger and heavier locomotives required more driving wheels, in order to provide enough adhesion whilst limiting axle load. Some earlier locomotives had already had four driven axles, but these had used either the B+B articulated arrangement or Bo′Bo′ with separate traction motors for each axle and two bogies.
![BLS Be 57 Fahrgestell mit Motoren und Transformatoren](https://upload.wikimedia.org/wikipedia/commons/5/5a/BLS_Be_57_Fahrgestell_mit_Motoren_und_Transformatoren.jpg)
The first electric locos to extend the 1′C1′ arrangement to 1′D1′ were the Swiss
Rhaetian Railway Ge 4/6 class of 1912. In the same year, the
Bern–Lötschberg–Simplon railway's used a 1′E1′ arrangement, with five driven axles, two traction motors of each and a rigid triangle rod drive to the centre axle. At the time, these were the world's most powerful electric locomotives. Each motor weighed 14 tons and was supplied by a separate transformer with a 12-stage tap changer. The taps for each motor were changed alternately, giving an effective 24 step control. The Swiss railways used low-frequency single-phase AC, at 11 kV for the Rhaetian and 15 kV for the BLS.
![Locomotiva FS E](https://upload.wikimedia.org/wikipedia/commons/2/29/Locomotiva_FS_E.431_037.jpg)
By 1922, the Italian three-phase system was also using heavier and more powerful
1′D1′ locomotives, such as the
FS Class E.431
The FS Class E.431 was a class of three-phase AC electric locomotives of the Italian State Railways (FS).
History
The E.431 was a class of 37 locomotives, built between 1922 and 1925 by Tecnomasio Italiano-Brown-Boveri (TIBB), divided into th ...
.
1′Do1′
Electric railways in the US had begun with low-voltage DC systems: 675 V (
Baltimore
Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...
) and 660 V (
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
). These early systems were based on direct connection to DC traction motors, without needing rectification, transformers or large diameter motors. Adequate power for main line haulage, even for the slower services through tunnels to the major urban terminii, required multiple motors. The Baltimore and Ohio used articulated Bo+Bo steeplecabs from the outset in 1895, the first main-line electric locomotives and over nine times heavier and more powerful than anything electric before. The
New York Central S-Motor though was a single rigid frame with four separately driven axles and two leading and trailing trucks. The traction motors at this time were simple ungeared motors, with the rotor mounted around the axle shaft. Two-pole
bipolar motor
A bipolar electric motor is an electric motor with only two (hence ''bi-'') poles to its stationary field. They are an example of the simple brushed DC motor, with a commutator. This field may be generated by either a permanent magnet or a field ...
s were used, where the rotors were sprung with the axles and wheels and the field coils fixed. As there were only two poles, horizontally to the sides of the rotor, the rotor was free to move up and down between them with the suspension.
![Bundesarchiv Bild 102-15748, Ausstellung](https://upload.wikimedia.org/wikipedia/commons/0/01/Bundesarchiv_Bild_102-15748%2C_Ausstellung_%22Deutsches_Volk-Deutsche_Arbeit%22.jpg)
The multiple motor Do arrangement, compared to the rod-drive locomotives and despite their powerful AC motors, had advantages for running at high speed, with no reciprocating mass to balance or give
hammer blow
In rail terminology, hammer blow or dynamic augment is a vertical force which alternately adds to and subtracts from the locomotive's weight on a wheel. It is transferred to the track by the driving wheels of many steam locomotives. It is an out-o ...
. Once geared and isolated traction motor drives were available, their
unsprung weight
The unsprung mass (colloquially unsprung weight) of a vehicle is the mass of the suspension, wheels or tracks (as applicable), and other components directly connected to them. This contrasts with the sprung mass (or weight) supported by the ...
could also be reduced, encouraging smooth running. Although many locomotives adopted the
Bo′Bo′
B-B and Bo-Bo are the Association of American Railroads (AAR) and British classifications of wheel arrangement for railway locomotives with four axles in two individual bogies. They are equivalent to the B′B′ and Bo′Bo′ classifications i ...
bogie arrangement and abandoned rigid frames, some fast passenger locomotives retained them into the 1940s and remained in service into the 1990s. Their large diameter driving wheels encouraged smooth running at speed and reduced the speed required from the motors and their gearing. Retaining frame-mounted motors also allowed large motors and adequate space for cooling airflow. A further advantage for four-motored Do locomotives, rather than the three-motored Co arrangement, is the ease with which the four motors can be switched between
series, parallel and series-parallel circuits. When this was used for three-motored locomotives, a double-wound armature on the motor was required.
![Doppelmotor E 19 1](https://upload.wikimedia.org/wikipedia/commons/3/39/Doppelmotor_E_19_1.jpg)
Germany constructed a series of these pre-war, the
DRG class E 16
The DRG Class E 16 were German electric locomotives in service with the Bavarian Group Administration of the Deutsche Reichsbahn, and were conceived as motive power for express trains. They were initially designated as the Bavarian Class ES 1, be ...
, ,
E 18 (Austrian
ÖBB 1018) and
E 19. They were of increasing technical sophistication, the first having the Buchli drive, later cup drives.
The power required for the last of these, the E 19, was such that were required with two motors for each axle.
(1′Do1′)+(1′Do1′)
The
Great Northern Z-1
The Great Northern Z-1 was a class of ten electric locomotives built for the Great Northern Railway They were used to work the route through the second Cascade Tunnel. They were built between 1926–1928 by Baldwin Locomotive Works, with Westing ...
class locomotives of 1927 were of 1′Do1′ layout, but operated as permanently coupled pairs, effectively (1′Do1′)+(1′Do1′). Each was built with a driving cab at each end, although only one was equipped. This gave them the possibility to be used as separate 1′Do1′ locomotives at some future time,
although this was never needed in practice and they remained coupled until withdrawn in favour of
dieselisation
Dieselisation (US: dieselization) is the process of equipping vehicles with a diesel engine or diesel engines. It can involve replacing an internal combustion engine powered by petrol (gasoline) fuel with an engine powered by diesel fuel, as o ...
in the mid-1950s.
and the 'Java bogie'
![JNR ED 54-2](https://upload.wikimedia.org/wikipedia/commons/7/75/JNR_ED_54-2.jpg)
This little-known variant of the 1′Do1′ articulates the trucks at each end by forming a bogie with one driven axle and one carrying axle.
Only a few examples of the (1A)Bo(A1) were built. They originated in Switzerland with the work of
Jakob Buchli
Jakob Buchli (4 March 1876 – 1 April 1945) was a Swiss design engineer in the field of locomotive construction.
Life
Jakob Buchli was born in Chur, Switzerland, on 4 March 1876. After his training to be an engineer he worked from 1902 to ...
of
Brown, Boveri & Cie
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 1 ...
, later
Swiss Locomotive and Machine Works
Swiss may refer to:
* the adjectival form of Switzerland
* Swiss people
Places
* Swiss, Missouri
* Swiss, North Carolina
*Swiss, West Virginia
* Swiss, Wisconsin
Other uses
*Swiss-system tournament, in various games and sports
*Swiss Internation ...
. The first were four express passenger locomotives, built by
SLM and
Brown, Boveri & Cie
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 1 ...
in 1924 in Switzerland for the
Electrische Staats Spoorwegen of
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
. These gave their name to the '
Java bogie
The Java bogie (german: Java-Drehgestell, Java-Gestell often in Swiss literature), was a bogie for electric locomotives manufactured by the Swiss Locomotive and Machine Works (SLM). It contained a driving wheel and a trailing wheel. It got its na ...
' for this form of articulation.
The bogie was arranged so that the pivot axis was just behind the pivoted driven axle. The axles were driven by
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 ...
s, to permit suspension movement, and as the pivot was so close to the axle this linkage could also absorb the bogie's movement, as the driven axle twisted in place but did not move sideways by much.
They were followed in 1926 by the two , later classified as ED54, for Japan, also built by SLM / BBC and with Buchli drives. These performed well, compared to other Japanese locomotives with nose-suspended traction motors, but were thought complicated and non-standard. With the culture of 1930s Japan and the increasing demand for self-reliance, rather than importing locomotives from overseas, they were used little and were withdrawn in 1948, despite this being the height of Japanese rebuilding post-war.
![Typenskizze GIPR EA1](https://upload.wikimedia.org/wikipedia/commons/e/e6/Typenskizze_GIPR_EA1.jpg)
A group of three different trial express passenger locomotives were supplied for the 1,500 V DC
Great Indian Peninsula Railway
The Great Indian Peninsula Railway (reporting mark GIPR) was a predecessor of the Central Railway (and by extension, the current state-owned Indian Railways), whose headquarters was at the Boree Bunder in Mumbai (later, the Victoria Terminu ...
in 1928. The first of these was most successful and followed by the
EA/1 class of 21 and later the single
A/2. They were asymmetric, with a 2′Bo(A1) arrangement and a Java bogie at one end; a four-wheeled bogie at the other supported the electrical equipment. This electrical equipment was supplied by
Metrovick
Metropolitan-Vickers, Metrovick, or Metrovicks, was a British heavy electrical engineering company of the early-to-mid 20th century formerly known as British Westinghouse. Highly diversified, it was particularly well known for its industrial el ...
but the locomotives were built by SLM and used their Winterthur drive, with paired traction motors above each axle, driving through a single central gear. The high-mounted motors were also found useful for services on flooded lines during the Indian monsoon.
![SBB Ae 8 14 11851](https://upload.wikimedia.org/wikipedia/commons/0/07/SBB_Ae_8_14_11851.jpg)
A derivative design was used for the Swiss 'double locomotives' of 1931, built for heavy freight service on the steep gradients of the
Gotthard Railway
The Gotthard railway (german: Gotthardbahn; it, Ferrovia del Gottardo) is the Swiss trans-alpine railway line from northern Switzerland to the canton of Ticino. The line forms a major part of an important international railway link between no ...
. These consisted of two articulated units as (1A)A1A(A1)+(1A)A1A(A1). A further unpowered carrying axle was also provided, splitting the central Bo group into A1A, which was needed by the extra weight of the transformer for the Swiss low frequency AC system. Again this was only a small class of three locomotives classed as
SBB Ae 8/14
The SBB-CFF-FFS Ae 8/14 is a class of electric locomotives built for Swiss Federal Railways to be used on the Gotthard railway. Only three prototype engines were built between 1931 and 1938, each of them in a different design.
The steep 2.7% g ...
, although each of the three was different. The first used the same Buchli drives, but from the second they introduced the
Winterthur Universal Drive, with paired traction motors driving each axle through a single central gear. This could be adapted more easily to the articulation. A drawback to the sheer size of these locomotives is that there were few trains heavy enough to require them, and when used to the full they were at risk of over-straining their couplings
![SBB Ae 4-6 Montage](https://upload.wikimedia.org/wikipedia/commons/9/95/SBB_Ae_4-6_Montage.JPG)
The Swiss
SBB Ae 4/6 of 1941 was derived from half of the 'double locomotive', with a more modern flat-fronted cab at each end. Weight saving in the traction motors allowed a return to the (1A)Bo(A1) layout, with the Java bogie and the Winterthur drive and avoiding the central carrying axle. They were also intended for use on the Gotthard route, but more flexibly as they could be used as individual units for lighter trains, or run in multiple as pairs for heavier trains. Both these and the Ae 8/14 had used regenerative braking, useful for descending the Gotthard's steep gradients without overheating and also returning electrical power to the network. The Ae 4/6 had a simplified and lighter system, where one traction motor could serve as the exciter for the others during braking. They were also built with aluminium windings in the transformer and motors, rather than copper.
In service, the Ae 4/6 performed well in some aspects, but had problems with a lack of adhesion and mechanical unreliability. Some aspects of their wartime construction may have reduced their mechanical build quality, leading to high noise levels in the final drives, and a susceptibility to bearing and gear failures, particularly after wheelslip.
![Spoorwegmuseum loc NS 1010](https://upload.wikimedia.org/wikipedia/commons/d/d1/Spoorwegmuseum_loc_NS_1010.jpg)
A Dutch class, the
NS 1000, were ordered from the same makers but were delayed by the war until 1948. Three were built by SLM, but the remainder were licence-built by
Werkspoor
Werkspoor N.V. was the shortened, and later the official name of the Nederlandsche Fabriek van Werktuigen en Spoorwegmaterieel. It was a Dutch machine factory, known for rolling stock, (ship) steam engines, and diesel engines. It was a successor ...
in the Netherlands. Although designed as passenger locomotives with a top speed of , they were soon found to be unreliable when used at speed and spent their working lives restricted to and mostly freight services. Despite this, they stayed in service until 1982.
2′Do2′
![Hugh llewelyn 2D2-5516 (5730117522)](https://upload.wikimedia.org/wikipedia/commons/d/d1/Hugh_llewelyn_2D2-5516_%285730117522%29.jpg)
The ultimate development of the rigid-framed electric locomotive was the 2′Do2′ arrangement. Four wheeled bogies replaced the pony trucks, giving better stability at high speeds. Four separate traction motors allowed high power. Sometimes a was used, where two motors were geared to the same axle.
The arrangement was first used as a conversion of the first production 1′Do1′
New York Central S-Motors, then known as the T-2, after an accident two days after entering service in 1907. They were then rebuilt as 2′Do2′ with bogies rather than single axle trucks and renamed to their original name as 'S-Motors'.
![2D2-9108 Villeneuve-Saint-Georges-a](https://upload.wikimedia.org/wikipedia/commons/9/97/2D2-9108_Villeneuve-Saint-Georges-a.jpg)
This arrangement was used in France, with the pre-war
2D2 5500 (1929–1943) and related classes, then the much improved post-war
2D2 9100 (1950).
In the mid-1950s, the
WAGR X class
The X Class were a class of diesel locomotive built by Beyer, Peacock & Company and Metropolitan-Vickers, Bowesfield Works, Stockton-on-Tees for the Western Australian Government Railways between 1954 and 1956.
Construction
In the early 1950s ...
diesel-electrics were built for the Western Australian railways. Their additional carrying axles allowed a low 12 ton axle loading, permitting their use across the whole network.
2′Do1′
![11026Ae47BaumaI](https://upload.wikimedia.org/wikipedia/commons/8/89/11026Ae47BaumaI.png)
The Swiss also used a large four-axle similar to the 2D2 5500, the 2′Do1′
Ae 4/7 (1927–1934). If length of service is considered, these were one of the most successful electric locomotive classes, lasting seventy years in service. They were a development of an earlier three-axle 2′Co1′ class, the . Both of these had an asymmetrical layout, with the pony truck at one end replaced by a four-wheel bogie. The Swiss low frequency AC system had the drawback of requiring heavy main transformers, compared to a 50 Hz system, and these were mounted at one end of the loco, needing the extra axle to carry their weight.
All of these, both French and Swiss, used
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 ...
s to couple the traction motors to the driving axles. The original Swiss drive used a single Buchli gear on one side to drive each axle, the French locomotives used a double-sided drive with the Buchli gear duplicated for each end of the axle, which was considered to reduce wear.
2′D1′
Asymmetrical layout had also been used for the for the
Silesian Mountain Railway
The Silesian Mountain Railway ( pl, Śląska Kolej Górska; german: Schlesische Gebirgsbahn) is a railway line in south-west Poland. It leads from Görlitz/Zgorzelec on the Lusatian Neisse via Jelenia Góra to Wałbrzych in Lower Silesia.
The fi ...
in 1918. This was the first of a number of 2′D1′ classes, also to support the weight of a large offset low-frequency transformer. They remained in service until the 1950s. These 2′D1′ classes began as a reluctant single prototype, built for comparison with the articulated 2′B+B1′ , which had themselves been a reaction to the poor performance of the 1912 1′D1′ .
A rare example of the 2′D2′ layout was the unique British diesel-mechanical
Fell locomotive
British Railways 10100 was an unusual experimental diesel locomotive known informally as ''The Fell Diesel Locomotive'' (after Lt. Col. L. F. R. Fell, who was one of the designers). It was the joint production of Davey Paxman & Co, Shell Refi ...
of 1955.
References
; Sources
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* {{Cite book
, title=Armstrong Whitworth: A Pioneer of World Diesel Traction
, first=Brian , last=Webb
, author-link=Brian Webb (railway historian)
, year=2010
, publisher=Lightmoor Publishing
, isbn=9781899889457
Electric locomotives