75.215—Longwall mining systems.
         For each longwall mining section, the roof control plan shall specify—
    
    
        
        (a) 
         The methods that will be used to maintain a safe travelway out of the section through the tailgate side of the longwall; and
    
    
        
        (b) 
         The procedures that will be followed if a ground failure prevents travel out of the section through the tailgate side of the longwall.