4-8-4

4-8-4 (Northern)

Santa Fe No. 3751

Equivalent classifications UIC class 2′D2′ French class 242 Turkish class 48 Swiss class 4/8 Russian class 2-4-2

First known tender engine version First use 1926 Country United States Locomotive NP class A Railway Northern Pacific Railway Designer American Locomotive Company Builder American Locomotive Company Evolved from 4-8-2, 4-6-4 Benefits Deeper firebox than the 4-8-2.

Under the Whyte notation for the classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type was first used by the Northern Pacific Railway, and initially named the Northern Pacific, but railfans and railroad employees have shortened the name since its introduction. It is most-commonly known as a Northern.