Meaning of Whyte classification

Whyte' classifica"tion

Pronunciation: (hwīt, wīt), [key]
  1. a system for classifying steam locomotives according to the total number of wheels on the front trucks, drivers, and rear trucks, in that order. For example, a Pacific locomotive is designated as 4-6-2.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.