EE WAS ASSISTING A COAL HAULER OPERATOR CHANGE OUT THE BATTERIES ON A COAL HAULER AND WAS ATTEMPTING TO GAIN HEIGHT BY BLOCKING BETWEEN THE HYUDRAULIC LIFT SYSTEM AND THE BATTERY CASE. WHEN HE PLACED THE BLOCKING BETWEEN THE LIFTING JACK AND THE BATTERY CASE HIS LEFT THUMB WAS CAUGHT AND SMASHED AGAINST THE BATTERY CASE. HE RECEIVED A LACERATION AND A FRACTURE TO THE TIP OF HIS LEF