2-10-10-2
Encyclopedia
Under the Whyte notation
for the classification of steam locomotive
wheel arrangement
s, a 2-10-10-2 is a locomotive with two leading wheel
s, two sets of ten driving wheel
s, and a pair of trailing wheel
s.
Other equivalent classifications are:
UIC classification
: 1EE1 (also known as German classification and Swiss classification)
Italian and French classification: 150+051
Turkish classification
: 56+56
Swiss classification: 5/6+5/6
The equivalent UIC classification
is refined to (1′E)E1′ for Mallet locomotives. All 2-10-10-2 locomotives have been articulated locomotive
s, Mallet locomotives in particular.
This wheel arrangement was rare. Only two classes of 2-10-10-2 locomotives have been built; the Atchison, Topeka and Santa Fe Railway
's 3000 class, and the Virginian Railway
's class AE.
This class of ten 2-10-10-2 locomotives were actually rebuilt from more conventional 2-10-2
Baldwin
-built locomotives by the Atchison, Topeka and Santa Fe Railway
in 1911.
Although they appeared to have exceedingly long boilers, the barrel in front of the rear set of cylinders actually contained first a primitive superheater
for further heating the steam before use; the steam was carried forward from the boiler proper by outside steam pipes as shown in the photograph. Also contained in this space was a reheater to give additional energy to the high-pressure exhaust before it was fed to the forward low-pressure cylinders.
In front of that, there was a feedwater heater
, a space where cold water from the tender could be warmed before being injected into the water proper. This worked similarly to the boiler itself; the firetubes passed through the feedwater tank.
The experiment was decidedly unsuccessful, and the locomotives were rebuilt back to 2-10-2s during 1915–1918.
for the Virginian Railway
. While suffering from the horsepower limitation of Mallets, which limited their speed, the locomotives had the highest tractive effort
of any steam locomotives ever built. Due to size limitations en route, they were delivered without their cabs and the front, low pressure cylinders, which were installed on site. The low pressure cylinders and the boiler were both the largest diameter ever used on a US locomotive; the cylinders had to be tilted slightly upward to provide sufficient clearance.
As can be seen in the photograph, the tenders fitted were unusually small; this so that they could use the Virginian's existing turntables
.
This class were true Mallet locomotive
s, in that as well as being articulated between the forward, swinging engine unit and the rear fixed one, they were also compound locomotive
s; the rear, high pressure cylinders exhausted their steam via a long pipe into the huge front cylinders. Like many compound locomotives, they could be operated in simple mode for starting; high pressure steam could be sent straight to the front cylinders at low speed, for additional tractive effort.
Unlike some other giant locomotives of the period, the immense boilers could generate enough steam to make them a success on the slow (8 mph or 13 km/h) coal trains for which they were built. They remained in service until the railroad electrified in 1952 and could be considered the ultimate drag era locomotive.
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...
for the classification of steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
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...
s, a 2-10-10-2 is a locomotive with two leading wheel
Leading wheel
The leading wheel or leading axle of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the leading wheels are normally located in a truck...
s, two sets of ten driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s, and a pair of trailing wheel
Trailing wheel
On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle located behind the driving wheels. The axle of the trailing wheels was usually located on a trailing truck...
s.
Other equivalent classifications are:
UIC classification
UIC classification
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
: 1EE1 (also known as German classification and Swiss classification)
Italian and French classification: 150+051
Turkish classification
Turkish classification
In the Turkish classification system for railway locomotives, the number of powered axles are followed by the total number of axles. It is identical to the Swiss system except that the latter places a slash between the two numbers.Thus0-6-0 becomes 33...
: 56+56
Swiss classification: 5/6+5/6
The equivalent UIC classification
UIC classification
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
is refined to (1′E)E1′ for Mallet locomotives. All 2-10-10-2 locomotives have been articulated locomotive
Articulated locomotive
Articulated locomotive usually means a steam locomotive with one or more engine units which can move independent of the main frame. This is done to allow a longer locomotive to negotiate tighter curves...
s, Mallet locomotives in particular.
This wheel arrangement was rare. Only two classes of 2-10-10-2 locomotives have been built; the Atchison, Topeka and Santa Fe Railway
Atchison, Topeka and Santa Fe Railway
The 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...
's 3000 class, and the Virginian Railway
Virginian Railway
The Virginian Railway was a Class I railroad located in Virginia and West Virginia in the United States. The VGN was created to transport high quality "smokeless" bituminous coal from southern West Virginia to port at Hampton Roads....
's class AE.
ATSF 3000 class
2-10-2
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...
Baldwin
Baldwin Locomotive Works
The Baldwin Locomotive Works was an American builder of railroad locomotives. It was located in Philadelphia, Pennsylvania, originally, and later in nearby Eddystone, Pennsylvania. Although the company was very successful as a producer of steam locomotives, its transition to the production of...
-built locomotives by the Atchison, Topeka and Santa Fe Railway
Atchison, Topeka and Santa Fe Railway
The 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...
in 1911.
Although they appeared to have exceedingly long boilers, the barrel in front of the rear set of cylinders actually contained first a primitive superheater
Superheater
A superheater is a device used to convert saturated steam or wet steam into dry steam used for power generation or processes. There are three types of superheaters namely: radiant, convection, and separately fired...
for further heating the steam before use; the steam was carried forward from the boiler proper by outside steam pipes as shown in the photograph. Also contained in this space was a reheater to give additional energy to the high-pressure exhaust before it was fed to the forward low-pressure cylinders.
In front of that, there was a feedwater heater
Feedwater heater
A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency of the system...
, a space where cold water from the tender could be warmed before being injected into the water proper. This worked similarly to the boiler itself; the firetubes passed through the feedwater tank.
The experiment was decidedly unsuccessful, and the locomotives were rebuilt back to 2-10-2s during 1915–1918.
Specifications
- Road numbers: 3000–3009
- Driver diameter: 57 in (1.4 m)
- Weight: 616,000 lb (279,400 kg = 279.4 t)
- Tractive effort: 111600 lbf (496.4 kN)
- Boiler pressure: 225 psi (1.6 MPa)
- Cylinder diameter: 28 in (711.2 mm) high pressure, 38 in (965.2 mm) low pressure
- Cylinder stroke: 32 in (812.8 mm)
Virginian Railway class AE
This class of ten locomotives were built in 1918 by ALCOAmerican Locomotive Company
The American Locomotive Company, often shortened to ALCO or Alco , was a builder of railroad locomotives in the United States.-Early history:...
for the Virginian Railway
Virginian Railway
The Virginian Railway was a Class I railroad located in Virginia and West Virginia in the United States. The VGN was created to transport high quality "smokeless" bituminous coal from southern West Virginia to port at Hampton Roads....
. While suffering from the horsepower limitation of Mallets, which limited their speed, the locomotives had the highest tractive effort
Tractive effort
As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...
of any steam locomotives ever built. Due to size limitations en route, they were delivered without their cabs and the front, low pressure cylinders, which were installed on site. The low pressure cylinders and the boiler were both the largest diameter ever used on a US locomotive; the cylinders had to be tilted slightly upward to provide sufficient clearance.
As can be seen in the photograph, the tenders fitted were unusually small; this so that they could use the Virginian's existing turntables
Turntable (railroad)
A railway turntable is a device for turning railroad rolling stock. When steam locomotives were still in wide use, many railroads needed a way to turn the locomotives around for return trips as their controls were often not configured for extended periods of running in reverse and in many...
.
This class were true Mallet locomotive
Mallet locomotive
The Mallet Locomotive is a type of articulated locomotive, invented by a Swiss engineer named Anatole Mallet ....
s, in that as well as being articulated between the forward, swinging engine unit and the rear fixed one, they were also compound locomotive
Compound locomotive
A compound engine unit is a type of steam engine where steam is expanded in two or more stages.A typical arrangement for a compound engine is that the steam is first expanded in a high-pressure cylinder, then having given up heat and losing pressure, it exhausts directly into one or more larger...
s; the rear, high pressure cylinders exhausted their steam via a long pipe into the huge front cylinders. Like many compound locomotives, they could be operated in simple mode for starting; high pressure steam could be sent straight to the front cylinders at low speed, for additional tractive effort.
Unlike some other giant locomotives of the period, the immense boilers could generate enough steam to make them a success on the slow (8 mph or 13 km/h) coal trains for which they were built. They remained in service until the railroad electrified in 1952 and could be considered the ultimate drag era locomotive.