Railway locomotive wheel arrangement
4-4-2 (Atlantic) Front of locomotive at left
First known tender engine version First use 1888 Country United States of America Locomotive Experimental double-firebox Designer George Strong Builder Hinkley Locomotive Works Evolved from 2-4-2 Benefits More stable than 2-4-2, Wide & deep firebox
Under the Whyte notation for the classification of steam locomotives by wheel arrangement , 4-4-2 represents a configuration of a four-wheeled leading bogie , four powered and coupled driving wheels , and two trailing wheels supporting part of the weight of the boiler and firebox. This allows a larger firebox and boiler than the 4-4-0 configuration.[citation needed ]
This wheel arrangement is commonly known as the Atlantic type, although it is also sometimes called a Milwaukee or 4-4-2 Milwaukee , after the Milwaukee Road , which employed it in high speed passenger service.[citation needed ]