USRA 2-6-6-2 Mallet
Elevation and sections drawings of a United States Railroad Administration (USRA) 2-6-6-2 compound articulated Mallet steam locomotive from the Jan. 31, 1919 issue of Railway Age.
Thirty 2-6-6-2s were built during the USRA era and were used on the Chesapeake and Ohio Railway (C&O) and Wheeling and Lake Erie Railway (W&LE). The C&O ordered additional 2-6-6-2 locomotives in later years that were only slightly modified from the original USRA design.
The complete article (3 pages) is available here: File:USRA 2-6-6-2 Mallet Steam Locomotive.pdf