Under the

Whyte notation Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twentieth cen ...

for the classification of steam locomotives by

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

, the is a Garratt locomotive. The wheel arrangement is effectively two 2-4-2 locomotives operating back to back, with the

boiler A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centr ...

and cab suspended between the two power units. Each power unit has a single pair of

leading wheel The leading wheel or leading axle or pilot wheel of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the leading wheels are normally located on a leading truck. Leading wheels are used ...

s in a leading truck, followed by two coupled pairs of driving wheels, with a single pair of trailing wheels in a trailing truck.

Overview

This was the rarest of all Garratt types, with only one class of four locomotives constructed to this wheel arrangement. It most likely evolved from the 2-4-0+0-4-2 Double Porter Garratt, with the trailing wheels added on each engine unit to improve stability at speed.

Usage

Brazil

All four 2-4-2+2-4-2 locomotives were built in 1943 by

Beyer, Peacock and Company Beyer, Peacock and Company was an English railway locomotive manufacturer with a factory in Openshaw, Manchester. Founded by Charles Beyer, Richard Peacock and Henry Robertson, it traded from 1854 until 1966. The company exported locomotives, ...

for the Leopoldina Railway in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. The locomotives were allocated engine numbers in the range from 400 to 403 on that system.

References

4,2-4-2+2-4-2 Whyte notation {{steam-loco-stub