Add Hesston's Shay #7 (Lima 1929 -- c/n 3345) to the list of multi-fueled engines.
Builders Photo shows R&H stack (assumed a wood burner), then shipped to New Mexico Lumber with a straight stack (coal). Some unknown later date, equipped with the current Rushton stack, probably while on Oregon Lumber Co. line. Converted to oil burner while "stored" in Baker City. Operated for a time as oil burner on Black Hills Central. Oil burning apparatus ripped out and left at Hill City when moved to Hesston June/July 1970. New wood grates found in Chicago and installed during the 1971 to 1975 rebuilding. Remains a woodburner following 2005/2006 rebuilding following 1985 engine house fire.

The one that immediately comes to my mind is the General. Built in 1855 as a wood burner and rebuilt about 1870 as a coal burner. She was rebuilt and converted back to a wood burner about 1891 and reconverted to a coal burner in 1892 and remained a coal burner until her third restoration in 1961 when she was converted to burn oil. Up until sometime around 1920, the locomotive traveled exclusively under her own power. When rebuilt in 1891, the officials did not realize how much trouble it would be to supply the locomotive fuel and that's why the locomotive was quickly converted back to a coal burner. Being a coal burner, they modified the Radley and Hunter stack to arrest coal embers and built a false deck on the tender which was strewn with wood. Coaling the locomotive must have been a real chore.