(a) The method of mining shall not expose any person to hazards
caused by excessive widths of rooms, crosscuts and entries, or faulty pillar
recovery methods. Pillar dimensions shall be compatible with effective
control of the roof, face and ribs and coal or rock bursts.
(b) A sightline or other method of directional control shall be used
to maintain the projected direction of mining in entries, rooms, crosscuts
and pillar splits.
(c) A sidecut shall be started only from an area that is supported in
accordance with the roof control plan.
(d) A working face shall not be mined through into an unsupported
area of active workings, except when the unsupported area is
(e) Additional roof support shall be installed where--
(1) The width of the opening specified in the roof control
plan is exceeded by more than 12 inches; and
(2) The distance over which the excessive width exists is
more than 5 feet.