4-6-2

4-6-2 (Pacific)

Front of locomotive at left

New Zealand's Q class, the first true Pacific locomotive

Equivalent classifications UIC class 2C1 (refined to 2′C′1′ or 2′C1′) French class 231 Turkish class 36 Swiss class 3/6 Russian class 2-3-1

First known tank engine version First use 1896 Country Australia Locomotive Q class Railway Western Australian Government Railways

First known tender engine version First use 1887 Country United States of America Railway Lehigh Valley Railroad Evolved from 4-6-0 Evolved to 4-6-4 Benefits Larger firebox than the 4-6-0 Drawbacks Required piloting (also known as double heading) when train lengths increased

First known "True type" version First use 1901 Country New Zealand Locomotive Q class Railway New Zealand Railways Department Designer Alfred Beattie Builder Baldwin Locomotive Works Evolved from 4-4-2, 4-6-0 & 2-6-2 Evolved to 4-6-4, 4-8-2 Benefits Wide and deep firebox behind coupled wheels

Under the Whyte notation for the classification of steam locomotives, 4-6-2 represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The 4-6-2 locomotive became almost globally known as a Pacific type after a locomotive built by the Baldwin Locomotive Works in Philadelphia was shipped across the Pacific Ocean to New Zealand.^[1][2]