A 4-4-6, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with:
The Providence, Warren and Bristol railroad's No. 4 Annawamscutt was the only example of a 4-4-6 in the United States. It was rebuilt into a 0-4-4T in 1891. [1]
The only example of this wheel arrangement in France was the Thuile locomotive.
Other equivalent classifications are: