The first example of this wheel arrangement was built in 1882 for the
Central Pacific. They named it "Mastodon". Otherwise, these were called
"Twelve Wheelers". On the Norfolk & Western, they were called "Mollies".
| No. | Class | F.M. Whyte | Gauge | Railroad Line | Location | Status | Notes |
|---|
| 2914 (2024) | TW-8 | 4-8-0 | 4'-8½" | SP | Kern County Museum, 3801 Chester Ave, Bakersfield, CA | display |    |
| 475 | M | 4-8-0 | 4'-8½" | N&W | Strasburg Railroad, Strasburg, PA | operational |  |
| 433 | M | 4-8-0 | 4'-8½" | N&W | The Virginia Creeper Trail, Abingdon, VA | display |   |
| 1134 | M2 | 4-8-0 | 4'-8½" | N&W | Railroad Museum of Virginia, Portsmouth, VA | display | From Virginia Scrap Iron and Metal. Displayed with tender from N&W 2-6-6-4. , |
| 1151 | M2c | 4-8-0 | 4'-8½" | N&W | Virginia Museum of Transportation, Roanoke, VA | display | From Virginia Scrap Iron and Metal. Displayed with tender from N&W 2-6-6-4. |
| 1118 | M2 | 4-8-0 | 4'-8½" | N&W | Roanoke Chapter NRHS, 9th Street Yard, Roanoke, VA | stored | From Virginia Scrap Iron and Metal, |