Under the

Whyte notation Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twentieth cen ...

for the classification of steam locomotives, 0-12-0 represents the

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

of no

leading wheel The leading wheel or leading axle or pilot wheel 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 on a leading truck. Leading wheels are used ...

s, twelve powered and coupled driving wheels on six axles, and no

trailing wheel On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle ( wheelset) located behind the driving wheels. The axle of the trailing wheels is usually located in a trailing truck. On some large locomotives, ...

Equivalent classifications

Other equivalent classifications are: *

UIC classification The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...

: F (also known as German classification and

Italian classification The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...

) *

French classification Under the French classification system for locomotive wheel arrangements, the system is slightly different for steam and electric/diesel vehicles. Steam The French system counts axles, rather than wheels. As with Whyte notation, a conventional r ...

: 060 *

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. Thus 0-6-0 beco ...

: 66 *

Swiss classification For more than a century, the Swiss locomotive, multiple unit, motor coach and railcar classification system, in either its original or updated forms, has been used to name and classify the rolling stock operated on the railways of Switzerland. ...

: 6/6

Tender engine

The first example of the 0-12-0 was the ''Pennsylvania'', designed by Jame Milholland for the

Philadelphia and Reading Railroad The Reading Company ( ) was a Philadelphia-headquartered railroad that provided passenger and commercial rail transport in eastern Pennsylvania and neighboring states that operated from 1924 until its 1976 acquisition by Conrail. Commonly called ...

and built at its own shops in 1863. It weighed fifty tons and was, at the time, the heaviest steam locomotive in the world. It was intended to haul Pennsylvania coal trains.

Tank engines

There were only two classes of 0-12-0T locomotives: The first was a class of three rack locomotives built by Lokomotivfabrik Floridsdorf in 1912 for use on the Erzberg Railway (''Erzbergbahn'') in Austria. Initially classified as class 269 by the

kkStB The Imperial-Royal State Railways (german: Imperial-Royal, k.k. Staatsbahnen) abbr. ''kkStB'') or Imperial-Royal Austrian State Railways (''k.k. österreichische Staatsbahnen'',The name incorporating "Austrian" appears, for example, in the 1907 of ...

, they passed to the BBÖ after World War I, the

Deutsche Reichsbahn The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...

in 1939, and finally the

ÖBB The Austrian Federal Railways (german: Österreichische Bundesbahnen, formally (lit. "Austrian Federal Railways Holding Stock Company") and formerly the or ''BBÖ''), now commonly known as ÖBB, is the national railway company ...

after World War II. They all stayed in service until the 1970s The only others of the type, was a class of ten 0-12-0T locomotives built by

Hanomag Hanomag (Hannoversche Maschinenbau AG, ) was a German producer of steam locomotives, tractors, trucks and military vehicles in Hanover. Hanomag first achieved international fame by delivering numerous steam locomotives to Finland, Romania and ...

in 1922 for the

Bulgarian State Railways The Bulgarian State Railways ( bg, Български държавни железници, translit=Balgarski darzhavni zheleznitsi, abbreviated as БДЖ, BDZ or BDŽ) are Bulgaria's state railway company and the largest railway carrier in the co ...

(BDŽ). They were initially numbered 4001–4010, but were renumbered 45.01 to 45.10 in 1935–1936. They were built as two-cylinder compound locomotives, with a boiler feeding a high-pressure cylinder discharging to a , both of which were connected to the driving wheels. The locomotives weighed .

References

* * * 12,0-12-0 Railway locomotives introduced in 1863 {{steam-loco-stub