Sep
9
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century. Whyte’s system counts the number of leading wheels, then the number of driving wheels, and finally the number of trailing wheels, with the groups of numbers separated by dashes. Thus, a locomotive with two leading axles (four wheels) in front, then three driving axles (six wheels) and followed by one trailing axle (two wheels) is classified as a 4-6-2. Here’s a good diagram detailing the Whyte notation for several different locomotives.
