Weyerhaeuser Timber Company No. 9
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-6-6-2 is a type of steam locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and one pair of trailing wheels. The wheel arrangement was principally used on Mallet-type articulated locomotives, although some tank locomotive examples were also built. A Garratt type locomotive with the same wheel arrangement is designated 2-6-0+0-6-2.
Under the UIC classification the wheel arrangement is referred to as (1'C)C1' for Mallet locomotives.
History[]
The 2-6-6-2 wheel arrangement was most often used for articulated compound steam Mallet locomotives. In a compound Mallet, the rear set of coupled wheels are driven by the smaller high pressure cylinders, from which spent steam is then fed to the larger low-pressure cylinders that drive the front set of coupled wheels.
This type of locomotive was commonly used in North America on logging railroads to haul log trains. The 2-6-6-2 wheel arrangement was also used in South Africa and the Soviet Union.
United States[]
Chesapeake & Ohio No. 1309
This "Chesapeake" wheel configuration existed on both the Norfolk & Western Railroad as Class L-76 (built by Norfolk & Western), later sold to Denver and Rio Grande Western, and the Denver and Rio Grande Western's standard gauge line as Class 340/L-62 (built by Alco-Schenectady), and in 1947 the Class L-76 from Norfolk & Western. D&RGW purchased these for helper service in 1910 (Soldier Summit and Tennessee Pass), and later added the two N&W locomotives to "beef up helper service" once again. All were retired between 1947 and 1952.
Chesapeake & Ohio 1309 is now operating on Western Maryland Scenic Railroad after a restoration completed in December 2020, replacing its companion, 734, which is undergoing evaluation. It operated on its first excursion in December 2021.
The Central of Georgia Railroad owned several 2-6-6-2s, and some time in the 1930s or 1940s, they exchanged 10 of their 2-6-6-2s to the Illinois Central for 10 World War 1 era 2-10-2s. The Illinois Central used the 2-6-6-2s only for hump yard duties. Two were sent to New Orleans, while the remaining eight were sent to Markham Yard in Chicago. They were all withdrawn and off the roster by 1956. All are presumed to have been scrapped by 1960.
Also a few of the 2-6-6-2T have been preserved some that are operational and some that are not operational.
Soviet Union[]
The wheel arrangement also appeared in Soviet Russia as a 5 ft (1,524 mm) locomotive, the P34, built by Kolomna Locomotive Works. It was a modern but compact Mallet of which only one was built.