2-2-0

A 2-2-0, in the Whyte notation for the classification of steam locomotives by wheel arrangement, has one unpowered leading axle and one powered driving axle. This type, which was one of the earliest ever produced, was commonly called the Planet type after the first locomotive built in 1830 to this configuration, Robert Stephenson's "Planet".

Other equivalent classifications are:

UIC classification: 1A (also known as German classification and Italian classification)

French classification: 110

Turkish classification: 12

Swiss classification: 1/2