6-2-0
Encyclopedia
In the Whyte notation
, a 6-2-0 is a railroad steam locomotive
that has an unpowered three-axle leading truck followed by a single powered driving axle. This wheel arrangement
is associated with the Crampton locomotive
type, and in the USA the single class were sometimes referred to as Cramptons.
Other equivalent classifications are:
UIC classification
: 3A (also known as German classification and Italian classification)
French classification: 310
Turkish classification
: 14
Swiss classification: 1/4
s rather than the powered driving wheel
s, therefore giving poor adhesion. The type was only practicable on the Crampton locomotive
with a low boiler and large driving wheels placed behind the firebox
.
for the London and North Western Railway
. It was exhibited at The Great Exhibition
in 1851 but was only moderately successful and no more were built.
and 96" diameter driving wheels.
Designing the locomotive type to burn coal, which was still fairly expensive and difficult to come by, was unusual for the time. The great majority of locomotives of the 1830s and 1840s were built to burn wood, which was very plentiful, cheap and exceptionally easy to obtain along the railroad rights of way. Besides being more expensive, coal required a larger firebox in which to burn. Dripps rose to the challenge and created an operable design.
The first of three locomotives based on these specifications, named John Stevens, was completed in 1849. Dripps wasn't too sure that the locomotive would prove effective on American railroads, and his reservations turned out to be correct. The locomotive's tractive effort was not sufficient for long term or heavy work. With only one driving axle and three unpowered leading axles, too much of the locomotive's weight was distributed over the unpowered lead three axles. Almost a century passed before a six-wheel leading truck was used again, on the PRR S1
and S2
.
The C&A's management, on the other hand, thought it performed admirably enough to order two more of them and place them in passenger service. It was claimed that they could reach 60 m.p.h. at a time when fast trains reached only 40 m.p.h. The 6-2-0s were later rebuilt to 4-4-0s and were in use as late as 1865.
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...
, a 6-2-0 is a railroad 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...
that has an unpowered three-axle leading truck followed by a single powered driving axle. This 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...
is associated with the Crampton locomotive
Crampton locomotive
A Crampton locomotive is a type of steam locomotive designed by Thomas Russell Crampton and built by various firms from 1846. The main British builders were Tulk and Ley and Robert Stephenson and Company....
type, and in the USA the single class were sometimes referred to as Cramptons.
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...
: 3A (also known as German classification and Italian classification)
French classification: 310
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...
: 14
Swiss classification: 1/4
History
The 6-2-0 was a most unusual wheel arrangement, where the bulk of the locomotive's weight was on the unpowered leading wheelLeading 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 rather than the powered driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...
s, therefore giving poor adhesion. The type was only practicable on the Crampton locomotive
Crampton locomotive
A Crampton locomotive is a type of steam locomotive designed by Thomas Russell Crampton and built by various firms from 1846. The main British builders were Tulk and Ley and Robert Stephenson and Company....
with a low boiler and large driving wheels placed behind the firebox
Firebox
In a steam engine, the firebox is the area where the fuel is burned, producing heat to boil the water in the boiler. Most are somewhat box-shaped, hence the name.-Railway locomotive firebox :...
.
United Kingdom
The only British 6-2-0 was the locomotive Liverpool built in 1848 by Bury, Curtis, and KennedyBury, Curtis, and Kennedy
Bury, Curtis and Kennedy was a steam locomotive manufacturer in Liverpool, England.Edward Bury set up his works in 1826, under the name of Edward Bury and Company. He employed James Kennedy, who had gained experience of locomotive production under Robert Stephenson and Mather, Dixon and Company,...
for the London and North Western Railway
London and North Western Railway
The London and North Western Railway was a British railway company between 1846 and 1922. It was created by the merger of three companies – the Grand Junction Railway, the London and Birmingham Railway and the Manchester and Birmingham Railway...
. It was exhibited at The Great Exhibition
The Great Exhibition
The Great Exhibition of the Works of Industry of all Nations or The Great Exhibition, sometimes referred to as the Crystal Palace Exhibition in reference to the temporary structure in which it was held, was an international exhibition that took place in Hyde Park, London, from 1 May to 15 October...
in 1851 but was only moderately successful and no more were built.
USA
On a trip to England, Robert L. Stevens, president of the Camden and Amboy (C&A) railroad, saw demonstrations of 6-2-0s on the railways there. When he returned in 1848, Stevens asked his master mechanic Isaac Dripps to build him a 6-2-0 for use on the C&A. The specifications for the first 6-2-0 included a 38" diameter boiler that would burn anthracite coalAnthracite coal
Anthracite is a hard, compact variety of mineral coal that has a high luster...
and 96" diameter driving wheels.
Designing the locomotive type to burn coal, which was still fairly expensive and difficult to come by, was unusual for the time. The great majority of locomotives of the 1830s and 1840s were built to burn wood, which was very plentiful, cheap and exceptionally easy to obtain along the railroad rights of way. Besides being more expensive, coal required a larger firebox in which to burn. Dripps rose to the challenge and created an operable design.
The first of three locomotives based on these specifications, named John Stevens, was completed in 1849. Dripps wasn't too sure that the locomotive would prove effective on American railroads, and his reservations turned out to be correct. The locomotive's tractive effort was not sufficient for long term or heavy work. With only one driving axle and three unpowered leading axles, too much of the locomotive's weight was distributed over the unpowered lead three axles. Almost a century passed before a six-wheel leading truck was used again, on the PRR S1
PRR S1
The PRR S1 class steam locomotive was an experimental locomotive that was the largest rigid frame passenger locomotive ever built. The streamlined Art Deco styled shell of the locomotive was designed by Raymond Loewy....
and S2
PRR S2
The Pennsylvania Railroad's class S2 was a steam turbine locomotive. Only one prototype was built, #6200, delivered in 1944. The S2 was the sole example of the 6-8-6 wheel arrangement in the Whyte notation, featuring a six-wheel leading truck, eight driving wheels, and a six-wheel trailing truck...
.
The C&A's management, on the other hand, thought it performed admirably enough to order two more of them and place them in passenger service. It was claimed that they could reach 60 m.p.h. at a time when fast trains reached only 40 m.p.h. The 6-2-0s were later rebuilt to 4-4-0s and were in use as late as 1865.