WHILE RIDING IN MANTRIP TRAVELING INTO MINE, THE MANTRIP HIT A POT HOLE IN ROADWAY IN MAINS ENTRY AT 3XC. THIS CAUSED THE EMPLOYEE TO BOUNCE OUT OF SEAT, HITTING HIS HEAD AGAINST THE ROOF OF T HE MANTRIP. EMPLOYEE WAS WEARING HIS HARD HAT ATTHAT TIME. DID NOT MISS WORK UNTIL 3-31-00.