4-6-0+0-6-4

4-6-0+0-6-4

Equivalent classifications UIC class 2C+C2 French class 230+032 Turkish class 35+35 Swiss class 3/5+3/5, 6/10 from 1920s Russian class 2-3-0+0-3-2

First known tank engine version First use 1912 Country Brazil Railway Mogyana Railway Designer Beyer, Peacock and Company Builder Beyer, Peacock and Company

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-6-0+0-6-4 is a Garratt articulated 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 Mallet type locomotives, but is referred to as 4-6-6-4. On a Mallet 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.^[1]
• The other was two locomotives built for the 3-foot gauge Ferrocarril Pacifico de Colombia by Armstrong Whitworth in 1924.^[2]

References