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 | ||
| 108 | 2-6-6-2T | 4'-8½" | Weyerhaeuser | Black Hills Central Railroad, Hill City, SD | operational | Baldwin #59087, 1926 | Restoration From Snoqualmie, WA. | |
| 110 | 2-6-6-2T | 4'-8½" | Rayonier (Weyerhaeuser) | Black Hills Central Railroad, Hill City, SD | operational | Baldwin #60561, 1928 | ||
| 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 | out of service | Baldwin #74278, 1949 | Restoration Named Maryland Thunder. 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. Taken out of service in December 2023. |
| 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. |