Under the Whyte notation for the classification of steam locomotives, 2-6-2 represents the wheel arrangement of two leading wheels, six coupled driving wheels and two trailing wheels. This arrangement is commonly called a Prairie.
CGR 2nd Class of 1875, the first 2-6-2
Victorian Railways class NA 2-6-2 tank locomotive on the Puffing Billy Railway
A Type 57 at Brussels South, 1957.
DB locomotive 23 071
The Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twentieth century following a December 1900 editorial in American Engineer and Railroad Journal.
Whyte notation from a handbook for railroad industry workers published in 1906