Most if not all locomotive designs with four-wheel trailing trucks were the result of the desire for more power and the need for a bigger firebox. The 2-6-6-4 design was no different. In 1934 Baldwin constructed three of this wheel arrangement for the P&WV (Pittsburgh & West Virginia) who desired to increase the speed of their freight trains.
This wheel arrangement was made most famous by the Norfolk & Western who perfected this design. The N&W had the most powerful 2-6-6-4s and used roller bearings on the axles. The last five were also equipped with roller bearings on the side and main rods!
High-speed articulateds generally were of two wheel arrangements -- the 2-6-6-4 and the 4-6-6-4. Baldwin was the primary builder of the 2-6-6-4 while ALCO was the primary builder of the 4-6-6-4. In the end, the 4-6-6-4 wheel arrangement became more popular.
|No.||Class||F.M. Whyte||Gauge||Railroad Line||Location||Status||Builder Info||Notes|
|1218||A||2-6-6-4||4'-8½"||N&W||Virginia Museum of Transportation, Roanoke, VA||display||N&W #340, 1943||status Operated in the Norfolk Southern's steam excursion program from April 1987 to November 1991. Rebuild began in 1992. NS steam program cancelled in December 1994. Now missing several parts and will likely never run again.|