Massive freight hauler used until 1960 to haul heavy coal trains through the Blue Ridge Mountains in Virginia and West Virginia. This compound "articulated" locomotive was among the hardest working steam locomotives ever built. The articulated design allowed the locomotive to operate on tracks with tighter curves by allowing the two sets of drive wheels to split and turn independently.  Weighs 961,500 pounds; the engine and tender are 113'1/4" long and have have 58" drivers. Only compound locomotive in Museum's collection. After being loaned out for five years to the Virginia Museum of Transportation, the #2156 was returned to TNMOT on June 15, 2020.