EMPLOYEE HAD SECURED A CHAIN ON TAIL PULLEY OF A CONVEYER IN ORDER TO HOIST AND MOVE IT. HE WAS HOLDING THE CHAIN TO MAINTAIN TENSION ON THE HOOK. HE THEN MOTIONED THE LOADER OPERATOR TO BEGIN HOISTING. AS THE CHAIN BEGAN TO TIGHTEN, HE NEGLECTED TO REMOVE HIS HAND FROM THE CHAIN. HIS INDEX FINGER WAS SEVERED AT 1ST DIGIT BETWEEN CHAINAND GUARD.