THE COAL FEEDER WAS FROZEN DUE TO COLD TEMPERATURES. EE WAS PULLING ON THE V-BELTS TO GET THE FEEDER DISLODGED. WHEN THE PITMAN ARM WAS FULLY EXTENDED THE FEEDER RELEASED & PULLED EE'S RIGHT T HUMB BETWEEN THE BELT & PULLEY CLOSEST TO THE ELECTRIC MOTOR. AT THIS TIME ALL SOURCES OF POWER TO THIS ONE FEEDER WERE DISCONNECTED. EE'S TOP PORTION OF RIGHT THUMB WAS SEVERED.