4-8-0+0-8-4

UIC class2D+D2

UIC class2D+D2

French class240+042

Turkish class46+46

4-8-0+0-8-4

Bengal Nagpur Railway class N 815

Equivalent classifications UIC class 2D+D2 French class 240+042 Turkish class 46+46 Swiss class 4/6+4/6, 8/12 from 1920s Russian class 2-4-0+0-4-2

First known tank engine version First use 1929 Country India Locomotive BNR class N Railway Bengal Nagpur Railway Designer Beyer, Peacock & Company Builder Beyer, Peacock & Company

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-8-0+0-8-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-0 locomotives operating back to back, with the boiler and cab suspended between the two engine units. Each engine unit has two pairs of leading wheels in a leading bogie, followed by four coupled pairs of driving wheels and no trailing wheels. A similar wheel arrangement exists for the Union Pacific Big Boy, but is referred to as 4-8-8-4 since only the front engine unit swivels.