CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER O—COAL MINE SAFETY AND HEALTH (parts 70 to 90) > PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES > SUBPART C—Roof Support (§75.200 to §75.223) > 75.203—Mining methods.

75.203—Mining methods.

(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 inaccessible.
(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.