The Whyte notation is a classification method for locomotives based on wheel arrangement. While the Whyte notation is most commonly used when referring to steam locomotives, it can also be applied to
Whyte notation from a handbook for railroad industry workers published in 1906
A tank locomotive, also called a tank engine, is a steam locomotive which carries its water in one or more on-board water tanks, instead of a more traditional tender. Most tank engines also have bunke
Whyte notation
…followed by the trailing wheels, each number being separated by a hyphen. A number of standard suffixes can be used to extend the Whyte notation for tank locomotives: Various other types of steam locomotive can be also denoted through suffixes…
GWR 14xx class autotank
A LSWR M7 Class, typical side tank locomotive from 1897
An example with a tapered front and cut-out to give access to the valve gear