Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 4-6-0+0-6-4 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.

4-6-0+0-6-4
Diagram of two small leading wheels, six large driving wheels in two trios, each trio joined by coupling rods, and two small trailing wheels
Equivalent classifications
UIC class2C+C2
French class230+032
Turkish class35+35
Swiss class3/5+3/5, 6/10 from 1920s
Russian class2-3-0+0-3-2
First known tank engine version
First use1912
CountryBrazil
RailwayMogyana Railway
DesignerBeyer, Peacock and Company
BuilderBeyer, Peacock and Company

A similar wheel arrangement exists for simple articulated locomotives, but is referred to as 4-6-6-4. On a simple articulated locomotive, only the front engine unit swivels while the rear unit is rigid in relation to the main frame.

Overview

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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]
4-6-0+0-6-4 Garratt production list – All manufacturers[1][2]
Gauge Railway Works no. Units Year Builder
3 ft Ferrocarril Pacifico de Colombia 565-566 2 1924 Armstrong Whitworth
1,000 mm Mogyana Railway, Brazil 5529-5530 2 1912 Beyer, Peacock
1,000 mm Mogyana Railway, Brazil 5787-5789 3 1914 Beyer, Peacock

References

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  1. ^ a b Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
  2. ^ a b Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives from Other Builders, retrieved 10 November 2012