In the Whyte notation for the classification of steam locomotive wheel arrangement, a 2-4-4-0 is a locomotive with two leading truck, two sets of four driving wheels, and no trailing truck. Examples of this type were constructed as Mallet locomotives.
The Chemins de Fer Departmentaux Vivarais and the Chemins de Fer Departmentaux Lozère each possessed 2-4-4-0 Mallet locomotives. The Société Alsacienne de Constructions Mécaniques built three for the Vivarais system in 1908 and two for the Lozère system in 1909.
Other equivalent classifications are:
- UIC classification: 1BB (also known as German classification and Italian classification)
- French classification: 120+020
- Turkish classification: 23+22
- Swiss classification: 2/3+2/2
- Russian classification: 1-2-0+0-2-0
The UIC classification is 1B'B.
- Organ, John (2000). "Chapter 3, p3 (unnumbered)". Southern France Narrow Gauge. Midhurst: Middleton Press. ISBN 1-901706-47-8.