4-4-0

4-4-0 ("American" or "Eight-Wheeler")

Front of locomotive at left

1836 Patent drawing of the first 4-4-0 locomotive

Equivalent classifications UIC class 2′B French class 220 Turkish class 24 Swiss class 2/4 Russian class 2-2-0

First known tank engine version First use 1849 Country United Kingdom Locomotive GWR Bogie Class Railway South Devon Railway Builder Great Western Railway

First known tender engine version First use 1836 Country United States Railway Philadelphia, Germantown and Norristown Railway Designer Henry Roe Campbell Builder Philadelphia, Germantown and Norristown Railway Evolved from 4-2-0 Evolved to 4-4-2 Benefits Better tractive effort than the 4-2-0 Drawbacks Could only pull a few cars due to its small size

4-4-0, in the Whyte notation, denotes a steam locomotive with a wheel arrangement of four leading wheels on two axles (usually in a leading bogie), four powered and coupled driving wheels on two axles, and no trailing wheels.

First built in the 1830s, locomotives with this wheel arrangement were known as "standard" or "Eight-Wheeler" type. In the first half of the 19th century, almost every major railroad in North America owned and operated locomotives of this type, and many rebuilt their 4-2-0 and 2-4-0 locomotives as 4-4-0s.^[1][2]

In April 1872, Railroad Gazette used "American" as the name of the type. The type subsequently also became popular in the United Kingdom, where large numbers were produced.^[1]

The vast majority of 4-4-0 locomotives had tenders, though some tank locomotives (designated 4-4-0T) were built.