Name used in North America for the steam locomotive type classified as 4-8-4 in the Whyte notation. Named after the Northern Pacific, the first railroad to order the type.
The Northern Pacific had an especial need for a locomotive with a bigger firebox than a 4-8-2 "Mountain" type could support, because they wanted to burn low-grade bituminous coal from mines they owned. This required a large, deep firebox to burn effectively.