0-6-0

scale model of a Finnish Vr1 type 0-6-0 tank locomotive from 1914 with outside cylinders.

The term "0-6-0" (pronounced 'oh-six-oh') is the Whyte notation for the wheel arrangement of a locomotive with six powered driving wheels (thus three powered axles), and neither leading nor trailing wheels. It mainly applies to steam locomotives.

Other equivalent classifications are:
UIC classification: "C" (also known as German classification and Italian classification)
French classification: "030"
Turkish classification: "33"
Swiss classification: "3/3"

In the UIC classification popular in Europe, the same arrangement is written as "C" (if the wheels are coupled with rods or gears) or "Co" (if they are independently driven).

Overview

Because they lack leading wheels (sometimes called guiding axles) at the front, 0-6-0 locomotives are not stable at high speed, so are mostly used on trains where high speed is unnecessary. But the lack of unpowered axles means that locomotives of this type have all their weight pressing down on their driving wheels, and consequently such locomotives have high tractive efforts and factor of adhesionfactors of adhesion, making them comparatively strong engines for their size, weight and fuel consumption.

Since they can pull heavy trains, albeit slowly, the 0-6-0 wheel arrangement was (and to some degree still is) commonly seen on switcherswitching (shuntershunting) locomotives the world over. By comparison, the smaller 0-4-0 type proved not to be large enough for locomotives of sufficient power to be versatile, while 0-8-0 and larger switching locomotives were too big to be economical or even usable on lightly-built railways such as dockyards and goods yards, precisely the sorts of places where switching locomotives were most needed. Between these two extremes, the 0-6-0 proved to be a 'sweet spot' that provided a good balance of power, versatility and economy.

Outside of switching, the 0-6-0 type was also used to pull freight and passenger trains on trips where high speed was not required, including suburban passenger services and pickup goods freight trains along branch lines.

Australia

In New South Wales, the New South Wales Z19 class locomotiveZ19 class was a tender type with this arrangement.

New Zealand
The 0-6-0 design was restricted to tank engines. The Hunslet-built M class of 1874 and Y class of 1923 provided 7 examples, however the F class built between 1872 and 1888 was the most prolific, with 88 examples, with 8 preserved examples.

Continental Europe
All the major continental Europe railways also 0-6-0s of one sort or another, though usually not in the proportions used in the United Kingdom. As in the United States, European 0-6-0 locomotives were largely restricted to switching and station pilot duties, though they were also widely used on short branch lines to pull passenger and freight trains. On most branch lines though, larger, more powerful tank engines tended to be favoured.

United Kingdom
In the United Kingdom, 0-6-0 tank locomotives were the most common locomotive type on all railways throughout the twentieth century. All of the Big Four British railway companiesBig Four companies to emerge from the Railways Act 1921Grouping used them in vast numbers. The Great Western Railway in particular had many of the type, most characteristically in the form of the pannier tank locomotive that remained in production well past NationalizationNationalisation in 1948. Equally popular for all but the heaviest freight work was the 0-6-0 tender (rail)tender locomotive which was built and used by virtually every railway company in the country from the mid-19th to the mid-20th century. The ultimate British 0-6-0 was the SR Class Q1Q1 'Austerity' type developed by the Southern Railway (Great Britain)Southern Railway during the Second World War to haul very heavy freight trains. It was the most powerful steam 0-6-0 design produced in Europe.

When diesel shunters began to be introduced, the 0-6-0 type became the most common. Many of the British Railways shunter types were 0-6-0s, including British Rail Class 03Class 03, the standard 'light' shunter, and British Rail Class 08Class 08 and British Rail Class 09Class 09, the standard heavier shunters.

United States

In the United States, huge numbers of 0-6-0 locomotives were produced, the majority of them being used as switchers. The USRA 0-6-0 was the smallest of the USRA standard locomotivesUSRA Standard classes designed and produced during the brief government control of the railroads through the United States Railroad AdministrationUSRA during World War I. 255 of them were built and ended up in the hands of about two dozen US railroads; in addition, many of them (and others) built numerous copies after the war. The Pennsylvania Railroad rostered over 1,200 0-6-0 types over the years, which were classed as type B on that system. US 0-6-0s were generally tender locomotives.

Military usage during the Second World War
During the Second World War no fewer than 514 USATC S100 Class 0-6-0 tank engines were built by the Davenport Locomotive Works for use by the Transportation Corps (United States Army)United States Army Transportation Corps in both Europe and North Africa. Some of these remained in service long after the war, having been purchased or otherwise adopted by the countries where they were used, including Austria, Egypt, France, Iraq, the United Kingdom and Yugoslavia. The SR USA Classfourteen engines purchased by the Southern Railway (UK)Southern Railway in 1946 remained in service well into the 1960s. Designed to be extremely strong but easy to maintain, these engines had a very short wheelbase that allowed them to operate on dockyard railways.

Inside cylinders

The first 0-6-0 with inside cylinders was built for the Leicester and Swannington Railway in 1834. Although inside cylinders were more difficult to build and maintain, and, in the early days, prone to breakage of the crank axles, the engines were more stable than their outside-cylindered counterparts. The design was so successful that it was the basic pattern for many goods engines over the next hundred years. The cramped space between the wheels was a factor in the choice of a wider Rail gaugegauge in some railways overseas.
In fiction
In The Railway Series, there are 5 steam locomotives and 4 diesel locomotives who have this configuration: Thomas the Tank EngineThomas, Toby the Tram EngineToby, Duck the Great Western EngineDuck, Donald and Douglas, Diesel, and Mavis (as well as Arry and Bert in the TV series).

External links
This site includes a full 1914 factory drawing of a Finnish 0-6-0 switcher.

See also
USATC S100 Class - A class of 0-6-0 built by American manufacturers for use in Europe during World War II

en.wikipedia.org