4-10-2
Encyclopedia
Under the Whyte notation
for the classification of steam locomotive
s, 4-10-2 represents the wheel arrangement
of four leading wheel
s on two axles (usually in a leading truck), ten powered and coupled driving wheel
s on five axles, and two trailing wheel
s on one axle (usually in a trailing truck). The class ran and rode better than the 2-10-2
type of locomotives.
Other equivalent classifications are:
UIC classification
: 2'E1' (also known as German classification and Italian classification)
French classification: 251
Turkish classification
: 58
Swiss classification: 5/8
in South Africa
, designed by G.W. Reid and built by Dübs and Company
of Glasgow
, later a part of the North British Locomotive Company
. It was known as the "Reid Tenwheeler". One hundred and one locomotives, later to become the South African Railways Class H
, were supplied between 1899 and 1903 for the Natal main line.
(SP), which called it "Southern Pacific" and the Union Pacific
(UP), which called it "Overland" after their corporate sobriquet, "The Overland Route".
According to Boynton's definitive book on the 4-10-2 in the U.S.A., there were only sixty engines built for domestic service and all were constructed as three cylinder
engines.
In 1925 the Southern Pacific placed an order for 16 locomotives and later in the same year, the Union Pacific ordered one. The SP engine No. 5000, completed in April 1925, bore builder's plate number 66107 while UP No. 8000, completed the following month, was number 66169.
Within a few months the SP ordered more engines and built up a fleet of 49. The UP waited thirteen months before repeating orders and establishing a fleet of 10 machines. All 59 were built by Alco and were single expansion.
In 1926 Baldwin Locomotive Works
constructed an experimental demonstrator, No. 60000
, which was a compound
, the only 4-10-2 so constructed. This engine used high pressure steam in the inside cylinder, then exhausted that steam into the two outside cylinders. It also had a water tube boiler, one of a very few locomotives so equipped in the United States. Baldwin's 4-10-2 was, said Boynton, 'outmoded before she left the factory' as steam compounding had lost favor in US railroading.
The three cylinder feature on these locomotives gave them a distinctive sound at work, described in Boynton, as a 'hop, skip, jump rhythm'. The third cylinder in the center of the cylinder saddle sloped down at a 9.5 degree angle to a crank on the second drivers' axle, while the two outside rods connected to the third drivers. The inside third rod created 'endless maintenance problems' because the floating bushings failed. Adding to the railway's maintenance problem, such failures required major valve re-settings and delays. Another unusual problem with the SP engines, Boynton said, was that the mechanical failures created such great pounding on the rails that railway housewives along the line complained of crockery cracking when a defective 4-10-2 rumbled past their homes.
The Union Pacific, said Boynton, tired of the heavy mechanical problems associated with three cylinders and in 1942, converted its engines to two-cylinder locomotives and renumbered them 5090-5099.
The SP engines, said Swengel, could operate only on relatively straight and heavily built main lines. Their long lives (from 28 to 30 years of service on the main line) were proof that they were good locomotives. However, despite the impressive service of the 4-10-2s on the UP, said Swengel, that railway still required bigger power that led to the building of its fleet of 4-12-2
s.
In November 1946, one of SP 4-10-2 engines No.5037 suffered a boiler explosion which killed four train crew.
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...
s, 4-10-2 represents the 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...
of four 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 on two axles (usually in a leading truck), ten powered and coupled driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s on five axles, and two 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 on one axle (usually in a trailing truck). The class ran and rode better than the 2-10-2
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...
type of locomotives.
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...
: 2'E1' (also known as German classification and Italian classification)
French classification: 251
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...
: 58
Swiss classification: 5/8
South Africa
This wheel arrangement was first used on the Natal Government RailwaysNatal government railways
The Natal Government Railways was formed in January 1877 in the Colony of Natal.In 1877 the Natal Government Railways acquired the Natal Railway Company for the sum of £40,000, gaining the line from the Point to Durban and from Durban to Umgeni...
in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, designed by G.W. Reid and built by Dübs and Company
Dûbs and Company
Dübs & Co. was a locomotive works in Glasgow, Scotland, founded by Henry Dübs in 1863 and based at the Queens Park Works in Polmadie. In 1903 it became part of the North British Locomotive Company.-Preserved locomotives:...
of Glasgow
Glasgow
Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...
, later a part of the North British Locomotive Company
North British Locomotive Company
The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...
. It was known as the "Reid Tenwheeler". One hundred and one locomotives, later to become the South African Railways Class H
South African Class H 4-10-2T
Between 1899 and 1903 the Natal Government Railways placed one hundred and one tank steam locomotives with a 4-10-2T wheel arrangement in service. In 1912, with the establishment of the South African Railways, the ninety-three "Reid Tenwheelers" that survived unmodified were designated Class...
, were supplied between 1899 and 1903 for the Natal main line.
United States
In the USA, the type was used only on the Southern PacificSouthern Pacific Railroad
The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....
(SP), which called it "Southern Pacific" and the Union Pacific
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....
(UP), which called it "Overland" after their corporate sobriquet, "The Overland Route".
According to Boynton's definitive book on the 4-10-2 in the U.S.A., there were only sixty engines built for domestic service and all were constructed as three cylinder
Cylinder (steam locomotive)
The cylinders of a steam locomotive are the components that convert the power stored in the steam into motion.Cylinders may be arranged in several different ways.-Early locomotives:...
engines.
In 1925 the Southern Pacific placed an order for 16 locomotives and later in the same year, the Union Pacific ordered one. The SP engine No. 5000, completed in April 1925, bore builder's plate number 66107 while UP No. 8000, completed the following month, was number 66169.
Within a few months the SP ordered more engines and built up a fleet of 49. The UP waited thirteen months before repeating orders and establishing a fleet of 10 machines. All 59 were built by Alco and were single expansion.
In 1926 Baldwin Locomotive Works
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...
constructed an experimental demonstrator, No. 60000
Baldwin 60000
Baldwin 60000 is an experimental steam locomotive built by the Baldwin Locomotive Works in Eddystone, Pennsylvania in 1926, during the height of the railroading industry. It received its number for being the 60,000th locomotive built by Baldwin....
, which was a compound
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...
, the only 4-10-2 so constructed. This engine used high pressure steam in the inside cylinder, then exhausted that steam into the two outside cylinders. It also had a water tube boiler, one of a very few locomotives so equipped in the United States. Baldwin's 4-10-2 was, said Boynton, 'outmoded before she left the factory' as steam compounding had lost favor in US railroading.
The three cylinder feature on these locomotives gave them a distinctive sound at work, described in Boynton, as a 'hop, skip, jump rhythm'. The third cylinder in the center of the cylinder saddle sloped down at a 9.5 degree angle to a crank on the second drivers' axle, while the two outside rods connected to the third drivers. The inside third rod created 'endless maintenance problems' because the floating bushings failed. Adding to the railway's maintenance problem, such failures required major valve re-settings and delays. Another unusual problem with the SP engines, Boynton said, was that the mechanical failures created such great pounding on the rails that railway housewives along the line complained of crockery cracking when a defective 4-10-2 rumbled past their homes.
The Union Pacific, said Boynton, tired of the heavy mechanical problems associated with three cylinders and in 1942, converted its engines to two-cylinder locomotives and renumbered them 5090-5099.
The SP engines, said Swengel, could operate only on relatively straight and heavily built main lines. Their long lives (from 28 to 30 years of service on the main line) were proof that they were good locomotives. However, despite the impressive service of the 4-10-2s on the UP, said Swengel, that railway still required bigger power that led to the building of its fleet of 4-12-2
4-12-2
Under the Whyte notation for the classification of steam locomotives, 4-12-2 represents the wheel arrangement of four leading wheels, twelve coupled driving wheels, and two trailing wheels.Other equivalent classifications are:...
s.
In November 1946, one of SP 4-10-2 engines No.5037 suffered a boiler explosion which killed four train crew.
Preservation
Two locomotives of this type have been preserved:- Southern Pacific 5021Southern Pacific 5021Southern Pacific Railroad number 5021 is an SP-2 class 4-10-2 steam locomotive built in 1926 by ALCO at their Schenectady, New York, shops...
, static display at the Los Angeles County Fairgrounds, Pomona, CaliforniaPomona, California-2010:The 2010 United States Census reported that Pomona had a population of 149,058, a slight decline from the 2000 census population. The population density was 6,491.2 people per square mile... - Baldwin 60000Baldwin 60000Baldwin 60000 is an experimental steam locomotive built by the Baldwin Locomotive Works in Eddystone, Pennsylvania in 1926, during the height of the railroading industry. It received its number for being the 60,000th locomotive built by Baldwin....
, moving display at the Franklin Institute Science Museum