TWO EMPLOYEES SENT A NEW MUCK BUCKET UNDERGROUNDON NORTH SIDE OF #30 SHAFT. THE BUCKET HUNG UP ABOUT 70' DOWN & CAUSED HOIST TO KICK OUT SLACK ROPE SWITCH. TWO CENTRAL SERVICE MAINTENANCE MEN WENT DOWN TO FREE UP BUCKET WHICH WAS BROUGHT UPTO LANDING AT 4:25 PM AND SHAFT INSPECTION WAS MADE. MSHA WAS CALLED AT 4:30 THE SAME DAY.