Frederick Methvan Whyte
Frederick Methvan Whyte (March 2, 1865 – 1941 Athens) was a mechanical engineer of Dutch background who worked for the New York Central in the United States. He is most widely known as the person who developed Whyte notation to describe the different wheel arrangements of steam locomotives in 1900.
AAR wheel arrangement
The AAR wheel arrangement system is a method of classifying locomotive (or unit) wheel arrangements that was developed by the Association of American Railroads. It is essentially a simplification of the European UIC classification, and it is widely used in North America to describe diesel and electric locomotives. It is not used for steam locomotives which use the Whyte notation instead.