81. When must a preshift examination be made of a belt conveyor and belt conveyor entry?

82. How often is the operator required to conduct searches for smoker's articles?

83. How often must fire drills and demonstrations of the various types of available fire-fighting equipment be held for employees?

84. What action must be taken by the mine operator, or the operator's management personnel, when the ventilation fan becomes disabled or inoperative?

85. At what maximum intervals are mandoors required to be installed in the intake and return stopping lines when the height of the coal is above 48 inches?

86. Where shall cutout switches be installed in trolley wires and trolley feeder wires?

87. At what intervals must fire hose outlets with valves be installed in track haulage entries when two portable water cars are not provided?

88. What maximum distance from a splice in a trolley wire must trolley wire hangers be installed?

89. What must all track haulage cars be provided with when they are regularly coupled and uncoupled?

90. What type of track mounted equipment must be provided with a trolley pole swing limiter?