Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-10-2 represents the arrangement of four leading wheels on two axles, usually in a leading bogie, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck. In South Africa, where the wheel arrangement was first used, the type was known as a Reid Tenwheeler. In the United States of America (USA) it was known as a Southern Pacific on the Southern Pacific Railroad and as an Overland on the Union Pacific Railroad.
Other equivalent classifications are:
- UIC classification: 2'E1' (also known as German classification and Italian classification)
- French classification: 251
- Turkish classification: 58
- Swiss classification: 5/8
Read more about 4-10-2: Overview