UIC classification of locomotive axle arrangements

The UIC classification of locomotive axle arrangements^[1] describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways (UIC) "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much of the world. The United Kingdom used a related scheme. The United States uses the simplified AAR wheel arrangement for modern locomotives.

1. ↑ "Standard designation of axle arrangement on locomotives and multiple-unit sets" (PDF).^{[permanent dead link]}