4-6-0+0-6-4
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the is a Garratt locomotive. The wheel arrangement is effectively two 4-6-0 ten-wheeler locomotives operating back to back, with the boiler and cab suspended between the two swivelling power units. Each power unit has two pairs of leading wheels in a leading bogie, followed by three coupled pairs of driving wheels and no trailing wheels.
A similar wheel arrangement exists for simple articulated locomotives, but is referred to as. On a simple articulated locomotive, only the front engine unit swivels while the rear unit is rigid in relation to the main frame.
Overview
This was a rare wheel arrangement for Garratt locomotives, with only seven locomotives built for two South American customers.- The first was for the metre-gauge Mogyana Railway of Brazil, with five examples built by Beyer, Peacock and Company in 1912 and 1914.
- The other was two locomotives built for the 3-foot gauge Ferrocarril Pacifico de Colombia by Armstrong Whitworth in 1924.
| Gauge | Railway | Works no. | Units | Year | Builder |
| Ferrocarril Pacifico de Colombia | 565-566 | 2 | 1924 | Armstrong Whitworth | |
| Mogyana Railway, Brazil | 5529-5530 | 2 | 1912 | Beyer, Peacock | |
| Mogyana Railway, Brazil | 5787-5789 | 3 | 1914 | Beyer, Peacock |