4-8-2

# 4-8-2

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Under the Whyte notation
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, 4-8-2 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), eight 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 four 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). This type of steam locomotive is also known as the Mountain type.

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′D1′ (also known as German classification and Italian classification)

French classification: 241 (also known as Spanish classification
Spanish classification
With the Spanish classification system for locomotive wheel arrangements, the system for steam machines.- Steam :With steam locomotives, there are three digits normally and more with articulated locomotives...

)

Russian classification: 2-4-1

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...

: 47

Swiss classification: 4/7

## History

Both the tank engine and tender engine versions of this wheel arrangement were designed 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...

and built in the UK.

### South Africa

The first 4-8-2 tank locomotive was designed by William Milne, locomotive superintendent of the Natal
Colony of Natal
The Colony of Natal was a British colony in south-eastern Africa. It was proclaimed a British colony on May 4, 1843 after the British government had annexed the Boer Republic of Natalia, and on 31 May 1910 combined with three other colonies to form the Union of South Africa, as one of its...

Government Railways in 1887. One hundred examples were 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:...

. They later became SAR Class A, and twenty-one were later converted into tender locomotives. Twenty five further tank engines were designed by Milne's successor, David Hendrie, and built by Dübs for the same railway in 1904 later becoming SAR Class G. Between 1910 and 1922 a number of Class H 4-10-2T were rebuilt as 4-8-2T to give them a better turning circle. These became SAR classes H1 and H2.

In 1906, six Class 1 4-8-0 tender locomotives were rebuilt as 4-8-2, in order to improve their stability on passenger trains, and these became SAR Class 1B. Thereafter the 4-8-2 became one of the most common locomotive types in South Africa with SAR Classes 3, 4, 12 & 15 built by 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...

between 1909 and 22; and Classes 19 & 23 built by Berliner Maschinenbau
Berliner Maschinenbau
Berliner Maschinenbau AG was a German manufacturer of locomotives.The factory was founded by Louis Victor Robert Schwartzkopff on 3 October 1852 as Eisengießerei und Maschinen-Fabrik von L. Schwartzkopff in Berlin ....

, between 1928 and 1936.

### New Zealand

The first of 18 X class
NZR X class
The NZR X class was a pioneering class of eighteen 4-8-2 steam locomotives designed by A. L. Beattie that operated on the national rail network of New Zealand...

4-8-2 De Glehn 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 were designed by A. L. Beattie
A. L. Beattie
Alfred Luther Beattie , typically referred to as A. L. Beattie, was a pioneering locomotive engineer. Born in Yorkshire, England, he gained fame as the Chief Mechanical Engineer of the New Zealand Railways Department between 1900 and 1913...

and built by New Zealand Railways Department
New Zealand Railways Department
The New Zealand Railways Department, NZR or NZGR and often known as the "Railways", was a government department charged with owning and maintaining New Zealand's railway infrastructure and operating the railway system. The Department was created in 1880 and was reformed in 1981 into the New...

's Addington Workshops
Addington Workshops
The Addington Railway Workshops was a major railway facility established in the Christchurch suburb of Addington in May 1880 by the New Zealand Railways Department. The workshops were previously in Carlyle Street and closed in 1990.-Description:...

in Christchurch
Christchurch
Christchurch is the largest city in the South Island of New Zealand, and the country's second-largest urban area after Auckland. It lies one third of the way down the South Island's east coast, just north of Banks Peninsula which itself, since 2006, lies within the formal limits of...

in 1908. It was designed to haul heavy freight trains on the mountainous central section of the North Island Main Trunk Railway. It is possible that this was the source of the "Mountain" nickname that was applied to the 4-8-2 type, though it is often said the name originates from the Chesapeake and Ohio Railway
Chesapeake and Ohio Railway
The Chesapeake and Ohio Railway was a Class I railroad formed in 1869 in Virginia from several smaller Virginia railroads begun in the 19th century. Led by industrialist Collis P...

in the United States, who named the type "Mountain" after the Allegheny Mountains
Allegheny Mountains
The Allegheny Mountain Range , also spelled Alleghany, Allegany and, informally, the Alleghenies, is part of the vast Appalachian Mountain Range of the eastern United States and Canada...

their first 4-8-2s were built to tackle.

One member of the pioneering X class survives and is currently located at the depot of the Feilding and District Steam Rail Society
Feilding and District Steam Rail Society
The Feilding and District Steam Rail Society, also known as Feilding Steam Rail, is a railway preservation society located in Feilding in the Manawatu region of New Zealand...

.

Although the X class was the first 4-8-2 locomotive, it is perhaps not a classic example of the type. The X class' trailing truck was positioned well behind a narrow firebox which itself sat above the driving wheels, necessitating the same design compromise between driving wheel diameter and boiler/grate size as a 2-8-0
2-8-0
Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...

or 4-8-0
4-8-0
Under the Whyte notation for the classification of steam locomotives, 4-8-0 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and no trailing wheels. The type was nicknamed the Mastodon or Twelve-wheeler in North America....

design. Later, more successful 4-8-2 designs were a progression of the classic 4-6-2
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

layout, which featured a wide firebox positioned above the trailing truck and behind the driving wheels, allowing for a large firebox as well as large driving wheels.

## USA

The 4-8-2 was most popular on the North American continent, where 4-6-2
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

Pacifics were becoming over-burdened as passenger trains grew in length and weight. The first North American 4-8-2 locomotives were built by ALCO
American 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 Chesapeake and Ohio Railway
Chesapeake and Ohio Railway
The Chesapeake and Ohio Railway was a Class I railroad formed in 1869 in Virginia from several smaller Virginia railroads begun in the 19th century. Led by industrialist Collis P...

in 1911. ALCO combined the traction of the eight-drivered 2-8-2
2-8-2
Under the Whyte notation for the classification of steam locomotives, 2-8-2 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

"Mikado" with the excellent tracking qualities of the Pacific's four-wheel leading truck.

Although the C&O intended their new Mountains for passenger service, the type proved ideal for the new, faster freight service the railroads were introducing. Many 4-8-2s were built for dual service.

Mountain type locomotives were built for 41 American railroads; about 2,200 were built. The largest users were the New York Central Railroad
New York Central Railroad
The New York Central Railroad , known simply as the New York Central in its publicity, was a railroad operating in the Northeastern United States...

with 435 of what they named the Mohawk
NYC Mohawk
The New York Central Railroad called the 4-8-2 type of steam locomotive the Mohawk type. It was known as the Mountain type on other roads, but the mighty New York Central didn't see the name to be fitting on its famous Water Level Route, so it instead picked the name of one of those rivers its...

type (the Water Level Route had no need for "Mountains", after all); the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

with 224 class M1
PRR M1
M1 is a class of steam locomotive of the Pennsylvania Railroad . It was a class of heavy mixed-traffic locomotives of the 4-8-2 "Mountain" arrangement, which uses four pairs of driving wheels with a four-wheel guiding truck in front for stability at speed and a two-wheel trailing truck to support...

, M1a and M1b locomotives, used mostly for fast freight service; the Florida East Coast with 90 passenger locomotives; the New Haven with 70; and the Southern Railway
Southern Railway (US)
The Southern Railway is a former United States railroad. It was the product of nearly 150 predecessor lines that were combined, reorganized and recombined beginning in the 1830s, formally becoming the Southern Railway in 1894...

with 58. The heaviest 4-8-2s were the twenty Illinois Central 2600 class built by the railroad 1945-46; close behind were B&M, L&HR, and D&RGW.

## Canada

The Canadian National Railway
Canadian National Railway
The Canadian National Railway Company is a Canadian Class I railway headquartered in Montreal, Quebec. CN's slogan is "North America's Railroad"....

operated eighty U-1 class 4-8-2 locomotives in passenger service (#6000–6079). Its last twenty (6060–6079) were delivered in 1944 with semi-streamlined conical smokebox covers that earned the nickname of “Bullet Nose Bettys”. Canadian Pacific Railway
Canadian Pacific Railway
The Canadian Pacific Railway , formerly also known as CP Rail between 1968 and 1996, is a historic Canadian Class I railway founded in 1881 and now operated by Canadian Pacific Railway Limited, which began operations as legal owner in a corporate restructuring in 2001...

's Angus Shops built a pair of 4-8-2s in 1914. While they were not replicated, CP kept them in service for 30 years. CP reverted to 4-6-2
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

Pacifics before moving to the 4-6-4
4-6-4
Under the Whyte notation for the classification of steam locomotives, 4-6-4 represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification:...

Hudson.

### Britain

Britain's population of Mountain locos consists entirely of two gauge locomotives on the Romney, Hythe and Dymchurch Railway
Romney, Hythe and Dymchurch Railway
The Romney, Hythe & Dymchurch Railway is a gauge light railway in Kent, England. The line runs from the Cinque Port of Hythe via Dymchurch, St...

, built by Davey Paxman & Co. in 1926. A number of Mountains were built for export; particularly the North British built J, Ja
NZR JA class
The NZR JA class were a type of 4-8-2 steam locomotive used on the New Zealand railway network. The class was built in two batches, with the second batch possessing some differences from the first...

and Jb
NZR JB class
The NZR JB class steam locomotives were all originally members of the J class of 1939. Built by North British Locomotive Works, Scotland, they all initially burned coal and wore distinctive bullet-like streamlining.- Conversion to oil burning :...

classes for secondary lines in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

.

### Bulgaria

In 1941 Bulgarian State Railways
Bulgarian State Railways
The Bulgarian State Railways are Bulgaria's state railway company and the largest railway carrier in the country, established as an entity in 1885. The company's headquarters are located in the capital Sofia. Since the 1990s the BDZ has met serious competition from automotive transport...

(BDZ) placed an order with Henschel & Sohn – Kassel (Germany) for the building of 50 standard gauge express passenger locomotives of type 2′D1′h3S (axle arrangement 2-4-1, simple steam expansion, superheating, 3-cylinder, fast train service), capable of hauling heavy passenger trains over the often severe profiles of Bulgarian main lines with gradients up to 2.8% (1 in 35.7). The first two engines were delivered by the end of 1941 and quickly proved the correctness of the specification of the BDZ engineers, who had previously experienced the insufficient power and some construction problems with classes 01 (1′D1′h2S) and 02 (1′D1′h3S). Next year mass production began, but was interrupted by war restrictions introduced by the German authorities; delivery ceased before the order was filled. Only 10 more engines were built and delivered, at the end of 1942 through the beginning of 1943, so the total number of the new BDZ class 03 remained 12 engines (03.01 – 03.12). After 1958 they were gradually converted to mixed fuel oil and coal firing, which resulted in improved steam production and facilitated service, particularly on mountainous lines. For about 35 years of use they showed excellent performance and minor problems (oval wearing of leading axle's inside crank). One of these machines, 03.12 (serial No. 26575) after factory repair was preserved in the depot of Gorna Oryahovitsa and is now completely restored and returned to operation under steam for tourist trains http://vlekov.snimka.bg/travel/sedmica-na-parnata-tyaga-v-ruse-30-04-2011-07-05-2011.593206.all.

Technical specifications:
 03 03.01 - 03.12 Class Numbers Gauge, mm Type (UIC) 2′D1′h3S Type (BDZ) Б2-4-117 Builder Henschel & Sohn - Kassel Year 1941-42 Steam pressure, kg/cm2 16 Superheater area 81.91 m² (881.7 sq ft) Heating area 224.07 m² (2,411.9 sq ft) Grate area 4.87 m² (52.4 sq ft) Cylinders no. x dia. x stroke, mm 3 x 500 x 700 Driving wheels diameter 1650 mm (65 in) Axleload, t 17.3 Adhesive weight, t 69.2 Total weight, t 179.18 Tender type 2′2′T28 Coal, t 13 Water 28 m³ (6,159.1 imp gal) Total length 23105 millimetre Total height 4580 millimetre Tractive effort, starting, kN 221 Tractive effort @ 20 km/h, kN 191 Train haulage rates, t: On level 1930 On 10‰ (1 in 100) gradient 825 On 25‰ (1 in 40) gradient 390 Max speed, km/h 100 km/h (62.1 mph)

### Czechoslovakia

The CSD introduced the 498.0 class 4-8-2 express passenger locomotive in 1938 after successful trials in the Tatra Mountains against an alternative 2-8-4
2-8-4
In the Whyte notation, a 2-8-4 is a railroad steam locomotive that has one unpowered leading axle followed by four powered driving axles and two unpowered trailing axles. This locomotive type is most often referred to as a Berkshire, though the Chesapeake and Ohio Railway used the name Kanawha for...

prototype. The design was further developed in 1954 into the 498.1 class. These technically sophisticated locomotives were reputedly capable of 11% thermal efficiency.

CSD also built a lighter and more numerous 4-8-2 class, numbered in the 475.xxx series.

### France

In France, these locomotives (known as the 241 type) were used on more undulating routes as increasingly heavy loads (caused by the use of all-steel passenger cars after 1918) began to overtax the hill-climbing capabilities of the existing 4-6-2
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

and the speed capabilities of 2-8-2
2-8-2
Under the Whyte notation for the classification of steam locomotives, 2-8-2 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

locomotives. Two hundred and seventy-five 4-8-2's were built for French service.
• The Est
EST
-Places:* Est , a town in Gelderland* Estonia, a nation in northern Europe** Estonian language, the Estonian language in ISO 639.2 or ISO 639–3 language codes* Est Region , one of Burkina Faso's 13 administrative regions...

railway took delivery of a prototype 4-8-2 four-cylinder compound locomotive, first numbered 41001, from its own Épernay shops in 1925. This was the first Mountain type built for commercial service within France.
• The Est subsequently ordered 41 production locomotives based on the prototype design, with improvements, in 1930. Their delivery took place over the following three years.
• The Etat
Etat
Etat is a Norwegian state-, county- or municipal agency. An Etat is a subdivision of the administration, which has been given responsibility for a special area. An agency does not have a board of directors, but it does have a director, appointed by the subordinate organization. Normally decisions...

(Ouest) obtained 50 copies of the Est design in 1930-31. Under SNCF management after 1938, these locomotives were transferred to the Est region and finished their service there.
• The PLM
Chemins de fer de Paris à Lyon et à la Méditerranée
The Compagnie des chemins de fer de Paris à Lyon et à la Méditerranée was a French railway company ....

introduced a class of 145 bullet-nosed 241A compound Mountain types in 1925 to accelerate trains over the Seuil de Bourgogne incline. This four cylinder 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...

was unusual in having short connecting rods for the outside (high pressure) cylinders pivoted on the first driving axle, rather than the second as is typical of most six or eight coupled wheel locomotives. Perhaps as a result of this, the locomotive did not run smoothly at speeds of greater than 100 km/h (63 mph). In order to save weight, the built-up locomotive frames were lightly constructed, which led to torsion and flexing which caused the wheel bearings to overheat. This problem was never solved on the PLM engines. However, true to the "Mountain" type they were able to haul heavy passenger trains over gradients at speed, taking an 800 tonne load over a 1 in 200 gradient at 90 to 100 km/h (56 to 63 mph).
• Based on the 241A, the unique PLM 241C (built 1930) had connecting rods linking the second and third driving axles. This locomotive served as the pattern for the development of the postwar standard SNCF 241P class.
• The PLM also experimented with a high-pressure watertube boiler on the unique 241B1 prototype, constructed with a German Schmidt-Henschel boiler in 1930. It was soon learned that this locomotive was a failure and it was retired and broken up by the mid-1930s.
• The Etat railway also built a prototype 3 cylinder simple-expansion 4-8-2 in 1932 which was an embarrassing failure for the company, but which was later converted by André Chapelon
André Chapelon
André Chapelon was a noted French mechanical engineer and designer of advanced steam locomotives. Engineer of Ecole Centrale Paris, he was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date knowledge and theories in...

into the legendary 242A1 4-8-4
4-8-4
Under the Whyte notation classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification: 2D2...

locomotive.
• The SNCF
SNCF
The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...

, with design input from André Chapelon
André Chapelon
André Chapelon was a noted French mechanical engineer and designer of advanced steam locomotives. Engineer of Ecole Centrale Paris, he was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date knowledge and theories in...

, developed the earlier PLM 241C into the 35-strong 241P class in 1948. These locomotives, although prone to axlebox problems caused by a frame not rigid enough for the (4000 indicated horsepower) output of the cylinders, were nevertheless very effective and some were still running into the early 1970s.

### Spain

Spain saw over 200 of these locomotives, also known as a 2-4-1, in five classes.

## Australia

Unlike other countries which utilised the 4-8-2 design for heavy passenger use, in Australia the 4-8-2 was more typically a heavy freight locomotive with small driving wheels and a very large firebox. The first 4-8-2s in Australia were gauge Q class of the Tasmanian Government Railways
Tasmanian Government Railways
The Tasmanian Government Railways was the former Government of Tasmania managed operator of mainline railways in Tasmania, Australia...

from 1922.

Armstrong Whitworth
Armstrong Whitworth
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. Headquartered in Elswick, Newcastle upon Tyne, Armstrong Whitworth engaged in the construction of armaments, ships, locomotives, automobiles, and aircraft.-History:In 1847,...

built ten 500 class 4-8-2s for the South Australian Railways
South Australian Railways
South Australian Railways built and operated railways in South Australia from 1854 to the incorporation of its non-urban railways into the Australian National Railways Commission in 1975, together with the former Commonwealth Railways and the former Tasmanian Government Railways...

in 1926, which at the time were the most powerful locomotive in Australia and the heaviest non-articulated locomotives built in Great Britain. Then, the three-cylinder NSWGR
New South Wales Government Railways
The New South Wales Government Railways was the government department that operated the New South Wales Government's railways until the establishment of the Public Transport Commission in 1972. Although later known officially as the Department of Railways, New South Wales, it was still generally...

D57 class of 1929 was one of the largest and most powerful locomotives ever built in Australia. With a large 65 sq ft (6.04 m²) grate
Grate
*A grate is a frame of iron bars to hold fuel for a fire.*It may also refer to a covering of a drain, also called a grating.*The act of using a grater, a kitchen utensil.- People :*Don Grate US sportsman....

and 64327 lbf (286.1 kN) 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...

, they were put to good use on the steep 1 in 40 (2.5%) gradient
Gradient
In vector calculus, the gradient of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change....

s leading out of Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

on NSW's mainlines. The design was further developed in 1950 with the smaller cylindered D58 class
New South Wales D58 class locomotive
The D58 class was a class of steam locomotives operated by the New South Wales Government Railways in Australia. They were built with the 4-8-2 wheel arrangement.- Construction :...

. However, this class proved to be less successful, suffering reliability problems attributed to the rack and pinion valve gear for the third cylinder used instead of the D57's Gresley/Holcroft
Gresley conjugated valve gear
The Gresley conjugated valve gear is a valve gear for steam locomotives designed by Sir Nigel Gresley, chief mechanical engineer of the LNER, assisted by Harold Holcroft...

valve gear.

The Western Australian Government Railways
Western Australian Government Railways
Western Australian Government Railways was most common name of the Western Australian government rail transport authority from 1890 to 1976. It is, in its current form, known as the Public Transport Authority of Western Australia....

introduced two classes of 4-8-2 locomotive for freight haulage on the state's network, the S class
WAGR S Class
The WAGR S Class is a class of 1067mm narrow gauge 4-8-2 Mountain-type steam locomotives built by the Western Australian Government Railways, with construction beginning in 1943...

of 1943 and W class
WAGR W Class
The "W" class is a group of narrow gauge steam locomotives operated by the WAGR and Silverton Tramway Co Ltd.-Engineering Background:The Western Australian Government Railways "W" class steam locomotive was first proposed by Chief Mechanical Engineer Fred Mills in 1947...

of 1951. The 4-8-2 layout allowed for the weight of these relatively powerful locomotives to be spread over a number of axles (the W class had a maximum axle load of just 10 tons) and also enabled the incorporation of a wide firebox for burning poor quality coal. The Tasmanian Government Railways
Tasmanian Government Railways
The Tasmanian Government Railways was the former Government of Tasmania managed operator of mainline railways in Tasmania, Australia...

also purchased a modern 4-8-2 from Robert Stephenson and Hawthorns
Robert Stephenson and Hawthorns
Robert Stephenson and Hawthorns Ltd was a locomotive builder with works in North East England.-History:The company was formed in September 1937 when Robert Stephenson and Company, which was based in Darlington took over the locomotive building department of Hawthorn Leslie and Company, based in...

in 1951. This was their H class.