4-8-4

Under the Whyte notation for the classification of steam locomotives, a '4-8-4' locomotive has four leading wheels, eight coupled driving wheels and four trailing wheels.
The equivalent UIC classification is '2'D2''.
The 4-8-4 was an obvious progression from the 4-8-2 "Mountain" and the 4-6-4 "Hudson" types, combining the 4-8-2's ability to have more weight on the driving wheels (leading to greater traction, and allowing a larger, more powerful locomotive) and the 4-6-4's larger firebox supported by a 4-wheel trailing truck, allowing for freer steaming, particularly at speed.

Contents

Development in the United States

Other countries

France

Germany

Australia

New Zealand

South Africa

Soviet Union

Brazil

China

Bolivia

Preservation

References

See also

Development in the United States

The first 4-8-4 was produced in 1927 by Alco for the Northern Pacific Railway, and the type was therefore named "Northern". Southern railroads in particular did not find this name very suitable, so they chose other names.

Railroad	Name
Canadian National Railway	Confederation
Central of Georgia Railroad	Big Apple
Chesapeake and Ohio Railway	Greenbrier
Delaware, Lackawanna and Western Railroad	Pocono
Denver and Rio Grande Western Railroad	Western
Grand Trunk Western Railroad	Confederation
Lehigh Valley Railroad	Wyoming
Nashville, Chattanooga and St. Louis Railway	Dixie
Ferrocarriles Nacionales de Mexico	Niágara
New York Central Railroad	Niagara
Richmond, Fredericksburg and Potomac Railroad	General, Governor, Statesman (three different classes)
Southern Pacific Railroad	Golden State (or General Service)
Western Maryland Railway	Potomac

The 4-8-4 proved to be the best choice of locomotive arrangement for both express passenger and fast freight service. It was not suited to heavy drag freight, but faster and lighter trains were well suited to the type.
The 4-8-4 was a late development and was often 'name' passenger power at the time of steam's demise, and many were are now preserved in museums, with a few in running condition.
Union Pacific Railroad 844, the last steam locomotive built for the UP, has never been retired from service. It is used for charter service and for publicity for the railroad. It is the only steam locomotive never retired by a Class I railroad.

Other countries

France

The lone SNCF 242A1 prototype, rebuilt from an unsuccessful Etat three-cylinder 4-8-2 simple expansion locomotive into a 4-8-4 compound locomotive. This remarkable locomotive achieved both extraordinary power outputs and efficiencies in coal and water use,^[1] but no further examples were built as SNCF focussed on electric traction for its future motive power development. 242A1 was scrapped in 1960.

Germany

The Deutsche Reichsbahn in 1939 took two prototypes of the BR 06 into service. They were designed for heavy express trains with a speed up to 140 km/h (87 mph).^[2] However due to World War II, no more units were produced and as trains in Germany are less heavy, no real need was seen for such a heavy express train locomotive. Many parts as the boiler were standardised and also used in BR 45 heavy freight train locomotives. Both BR 06 prototypes were scrapped in the 1950s.

Australia

Three classes of 4-8-4 tender locomotive have been built for use in Australia:

★ The South Australian Railways 500 class of 1926, originally a 4-8-2 design, was modified in 1929 into the 4-8-4 500B class by the replacement of the trailing axle with a booster-equipped four-wheel trailing truck.^[3]

★ The Victorian Railways H class three-cylinder 4-8-4 of 1941, designed for heavy passenger work on the Melbourne-Adelaide line. It was the largest non-articulated locomotive built in Australia.^[4] Due to the necessary upgrades to the Adelaide line being deferred, the H class operated only on the Melbourne-Albury line, achieving success as a fast freight locomotive.

★ The streamlined South Australian Railways 520 class of 1943, able to run on lightly-constructed 30 kg/m (60 lb/yd) track by virtue of the engine unit's weight being spread over eight axles.^[5] Their streamlining bears a strong resemblance to that of the PRR T1 locomotive.

New Zealand

The NZR K, K^A and K^B classes were introduced from 1932 onwards to meet a requirement for a more powerful locomotive that could operate within New Zealand's tight loading gauge.^[6]

South Africa

In 1953, a time when 4-8-4s on many American railroads were being replaced by diesel-electric locomotives, South African Railways introduced the Class 25 4-8-4.^[7] These powerful locomotives were effectively a continuation of American 4-8-4 locomotive design, scaled down slightly for narrow gauge operation.^[8] A novel feature of many of these locomotives was the use of enormous condensing tenders, designed to save water in arid areas by converting exhaust steam back to water.^[9]
In 1981, a Class 25 locomotive was rebuilt into the experimental Class 26NC "Red Devil". This relatively compact locomotive (the engine unit weighed just 123 tonnes) was capable of extraordinary power (in excess of 4,000 drawbar horsepower) yet delivered exceptional economy in coal and water use.^[8] However, like the French 242A1 4-8-4 built 35 years earlier, the 26NC remained a one-off. SAR had decided to modernise its fleet with diesel and electric traction rather than invest further development in steam traction.

Soviet Union

The 4-8-4 arrangement was represented in the Soviet Union by the P36 series locomotive. As the last Russian standard class steam locomotive, they shared some common components and design attributes with the earlier standard designs, the L class 2-10-0 and LV 2-10-2, plus common attributes with the P34 2-6-6-2 Mallet and P38 2-8-8-4 Mallet. They were the only semi-streamlined steam locomotives built in Russia, although a number of fully streamlined locomotives were built. 251 examples were produced from 1954 to 1956.

Brazil

French-built meter gauge 4-8-4 type designed by Frenchman André Chapelon after the left SNCF (where he had designed the only French 4-8-4). ALCO also built 4-8-4s for Brazil.

China

China's 4-8-4s were the 'KF' class. Chinese Government Railways Class KF1 designed by Colonel Kenneth Cantlie No 607 is preserved by the National Railway Museum, UK.

Bolivia

Bolivia had 4-8-4s.

Preservation

Many 4-8-4 locomotives have been preserved in museums, and a few are in operational condition. Some of the more notable of this type are:



★ Atchinson, Topeka & Santa Fe 3751 - Restored in 1991, owned by the San Bernardino Railroad Historical Society

★ Chesapeake & Ohio 614 - Restored in 1980 and again in 1995, owned by Iron Horse Enterprise

★ Ferrocarriles Nacionales de México 3028 - Retired in 1966, acquired by the Great North Eastern Railroad Foundation and displayed at the Altamont, New York, fairgrounds until 1983. Currently on lease to and being restored by the New Hope and Ivyland Railroad. Eleven other N de M Niagara QR-1 class locomotives are preserved in various locations in Mexico; one (in Puebla) is operational. ^[12]

★ Grand Trunk Western 6325 - Restored in 2001 by the Ohio Central Railroad

★ Milwaukee Road 261 - Restored in 1993, owned by the National Railway Museum in Green Bay, WI. Leased by North Star Rail in St. Paul, MN

★ New Zealand Government Railways K 900 - on static display at MOTAT in Auckland

★ K 911 - under overhaul at Mainline Steam, Wellington.

★ K 917 - stored Steam Incorporated, Wellington

★ K^A 935 - operating on the Silver Stream Railway, near Wellington, New Zealand.

★ K^A 942 - under overhaul at Mainline Steam, Wellington
★ Kb 968 - under overhaul at Mainline Steam, Christchurch

★ K^A 945 - under overhaul at Steam Incorporated, Wellington

★ Norfolk & Western 611 - Ran frequent excursions in the 1980s and early 1990s, on display in the Virginia Museum of Transportation.

★ Reading 2100 - Restored in 1988, and 1998, converted to burn oil in the Early 2000s. In 2006 in Tacoma, WA for excursion service.

★ Reading 2124 - Used on the "Reading Rambles" in the late 1950s and 1960s. On static display at Steamtown in Scranton, PA.

★ St. Louis Southwestern 819 - Built in 1943, it was the last locomotive build by the Cotton Belt. Restored to service in 1986 and housed at the Arkansas Railroad Museum in Pine Bluff, AR

★ St. Louis-San Francisco Railway 4501 - Built in 1942, ran overnight passenger service between St. Louis, Tulsa, and Oklahoma City. Donated to the Dallas Museum of the American Railroad in September 1964

★ Spokane, Portland and Seattle 700

★ South Australian Railways 504 - in static preservation at the National Railway Museum in Port Adelaide.

★ South Australian Railways 520 - Restored to service in 1972, operating the Steamranger tourist railway between Mt Barker and Victor Harbor

★ Southern Pacific 4449 - still in operation, served as the locomotive for the Bicentennial American Freedom Train

★ Southern Pacific 4460 - on static display at the Museum of Transportation in St. Louis, Missouri. This was the last steam locomotive used in revenue service by the SP.

★ Union Pacific 844 - the last steam locomotive built for Union Pacific Railroad, running in excursion service.

★ P36 no.0032 - the only private steam locomotive operated in Russia. Owned by GW Travel.

References

1. chapelon.net Technical Data Index - retrieved 1 November 2006
2. dbtrains.com BR 06 - retrieved 1 November 2006
3. National Railway Museum - 500B-class 4-8-4 steam locomotive No.504 "TOM BARR-SMITH" - retrieved 1 November 2006
4. ARHS Railway Museum: What to see - H220 - retrieved 15 October 2006
5. National Railway Museum - 520-class 4-8-4 steam locomotive No.523 "Essington Lewis" - retrieved 1 November 2006
6. ipenz.org.nz Engineering Heritage - retrieved 1 November 2006
7. SAR Class 25NC 4-8-4 - retrieved 3 November 2006
8. The Ultimate Steam Page - David Wardale - retrieved 3 November 2006
9. SAR Class 25 4-8-4 - retrieved 3rd November 2006
10. The Ultimate Steam Page - David Wardale - retrieved 3 November 2006
11. (based on SNCF 242A1 and DR BR 06 locomotives being scrapped) steamtrainartist.com Victorian Railways H Class 4-8-4 - retrieved 1 November 2006
12. Steam Locomotive dot com

See also

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