4-8-2

Under the Whyte notation for the classification of steam locomotives, 4-8-2 represents the wheel arrangement of four leading wheels on two axles, usually in a leading truck or bogie, eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle, usually in a trailing truck. This type of steam locomotive is commonly known as the Mountain type.

Other equivalent classifications are:

• UIC classification: 2′D1′ (also known as German classification and Italian classification)
• French classification: 241 (also known as Spanish classification)
• Turkish classification: 47
• Swiss classification: 4/7
• Russian classification: 2-4-1