It wasn't until 1910 that 2-6-6-2s were built with their firebox behind the drivers and supported by the trailing truck which is normally why one would have a trailing truck. Subsequent 2-6-6-2s were built following this design.
The 2-6-6-2 was primarily a low-speed locomotive. This wheel arrangement was also commonly used on the logging railroads in the Western USA. However, the C&O (Chesapeake & Ohio) continued developing the 2-6-6-2. Their versions evolved into very large road locomotives. With their smokebox-mounted air pumps, they looked quite impressive. Fortunately, two of these class H-6 C&O locomotives survive today.
This wheel arrangement was also used by the Southern Pacific in their development of the Cab Forward locomotive. On the SP this wheel arrangement was called a "Mallet Mogul".
| No. | Class | F.M. Whyte | Gauge | Railroad Line | Location | Status | Builder Info | Notes |
|---|---|---|---|---|---|---|---|---|
| 46 (110) | 2-6-6-2 | 4'-8½" | CWR (Weyerhaeuser) | Pacific Southwest Railway Museum, Campo, CA | display | Baldwin #62064, 1937 | Appeared in There Goes A Train. | |
| 12 | 2-6-6-2 | 4'-8½" | SW Forest Ind | Pioneer Historical Museum, 2340 N Ft Valley Rd (US 180), Flagstaff, AZ | display | Baldwin #60870, 1929 | ||
| 110 | 2-6-6-2T | 4'-8½" | Rayonier (Weyerhaeuser) | Black Hills Central Railroad, Hill City, SD | operational | Baldwin #60561, 1928 | ||
| 108 | 2-6-6-2T | 4'-8½" | Weyerhaeuser | Black Hills Central Railroad, Hill City, SD | operational | Baldwin #59087, 1926 | Restoration From Snoqualmie, WA. | |
| 1308 | H-6 | 2-6-6-2 | 4'-8½" | C&O | C.P. Huntington RR Hist Soc, Huntington, WV | display | Baldwin #74277, 1949 | One of only two surviving C&O 2-6-6-2s, the other one being C&O (WMSR) 1309. Placed on the National Register of Historical Places on January 31, 2003. |
| 38 | 2-6-6-2 | 4'-8½" | Weyerhaeuser | Modoc Northern Siding, Merrill, OR | dismantled | Operated by Rayonier INC. until 1968, making her the last Baldwin logging mallet to be retired from commercial use. From a lot a mile from Great Western Railroad Museum, McCloud, CA, Fred Kepner collection. Being kept by the Oregon Coast Scenic. | ||
| 1309 | H-6 | 2-6-6-2 | 4'-8½" | WM (C&O) | Western MD Scenic Shops, Ridgeley, WV | operational | Baldwin #74278, 1949 | Restoration From the B&O Railroad Museum. Last steam locomotive built by Baldwin. Test fired and moved under its own power on December 31, 2020. Debuted in excursion service on December 17, 2021. |
| 6 | 2-6-6-2 | 4'-8½" | Weyerhaeuser | Northwest Railway Museum, Snoqualmie, WA | display | Baldwin #60412, 1928 | Operated from 1969 to 1974. | |
| 11 | 110 ton | 2-6-6-2 | 4'-8½" | US Plywood | Northwest Railway Museum, Snoqualmie, WA | display | Baldwin #59701, 1926 | Operated from 1974 to 1990. |
| 4 | 2-6-6-2T | 4'-8½" | Clover Valley | Niles Canyon Railway, Sunol, CA | operational | Baldwin #57684, 03/1924 | Ran test runs in the summer of 2012. | |
| 8 | 2-6-6-2T | 4'-8½" | Rayonier | Roots of Motive Power, Willits, CA | restoration | Baldwin #58064, 1924 | From Shelton, then Chehalis, WA. |