4-4-2+2-4-4

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 & Company, the owner of the Garratt patent.^[1]

Eight locomotives were built for Argentina to run on 4 ft 8+1⁄2 in (1,435 mm) standard gauge .^[1]

• Five were built for the Entre Ríos Railway in 1927.^[1]
• Another three were built for the Argentine North Eastern Railway in 1930.^[1]

After nationalization in 1948, all these locomotives were rostered on the General Urquiza Railway.^[1]

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.^{[1] [2]}

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 They were difficult to maintain and, despite their haulage abilities and speed, both were withdrawn from service some time after the arrival of the R class in 1924 and scrapped in the late 1940s.^[2]

Media related to 4-4-2+2-4-4 locomotives at Wikimedia Commons

• Garratt locomotives
• Whyte notation

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• Short description matches Wikidata
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