THE HOIST MAN ON SHIFT WAS PULLING A CAR OF SHOT ROCK OUT OF THE SLOPE. WHEN HE TRIED TO STOP THE CAR AT THE ROLLOVER DUMP THE CONTROLLER DIDN'T STOP THE CAR. THE CAR WAS STOPPED BY THE OVERTR AVEL LIMIT AT THE TOP. HOWEVER, SOME BEAMS WERE DAMAGED IN THE HEAD FRAME & HAD TO BE REPLACED. AFTER REPAIRS WERE MADE, THE HOIST WAS TESTED; THE CONTROLLER WAS CHANGED AS A PRECAUTION.