Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-4-2+2-4-4 is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-4-2 locomotives operating back to back, with each power unit having four leading wheels on two axles in a leading bogie, four powered and coupled driving wheels on two axles, and two trailing wheels on one axle in a trailing truck. Since the 4-4-2 type is usually known as an Atlantic, the corresponding Garratt type is often referred to as a Double Atlantic.
The 4-4-2+2-4-4 was not a common Garratt wheel arrangement. Only ten were built, all by Beyer, Peacock and Company, the owner of the Garratt patent.
|3 ft 6 in||Tasmanian Government Railways||M||5523–5524||2||1912||Beyer, Peacock|
|4 ft 8 1⁄2 in||Entre Rios Railway (FCER), Argentina||6360–6364||5||1927||Beyer, Peacock|
|4 ft 8 1⁄2 in||Argentine North Eastern (FCNAR)||6645–6647||3||1930||Beyer, Peacock|
Eight locomotives were built for Argentina to run on 4 ft 8 1⁄2 in (1,435 mm) standard gauge.
- Five were built for the Entre Ríos Railway (Ferrocarril Entre Ríos, FCER) in 1927.
- Another three were built for the Argentine North Eastern Railway (Ferrocarril Nordeste Argentino, FCNAR) in 1930.
After nationalization in 1948, all these locomotives were rostered on the Ferrocarril General Urquiza (FCGU).
The first Garratt locomotives to be built to the 4-4-2+2-4-4 wheel arrangement were a pair of M class passenger locomotives for the 3 ft 6 in (1,067 mm) gauge Tasmanian Government Railways in Australia in 1912. They were acquired to haul express passenger trains between Launceston and Hobart.
The two M class engines were the only eight-cylinder Garratt locomotives in the world. They were difficult to maintain and, despite their haulage abilities and speed, both were withdrawn from service some time after the arrival of the R class 4-6-2 Pacific types in 1924. Both locomotives were scrapped and cut up in the late 1940s.
|Wikimedia Commons has media related to 4-4-2+2-4-4.|
- Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
- Garratt Locomotives - TGR K, L, M & G Classes - EBR Beyer-Garratt and ASG Types (Accessed on 8 October 2016)