A. The active workings of a mine shall be ventilated by means of main fans.
B. Unless otherwise approved by the Chief, each fan shall be (i) provided with pressure-recording gauges, (ii) installed on the surface in a fireproof housing, and (iii) equipped with fireproof air ducts.
C. In addition to the requirements of subsection B, each main fan shall either:
1. Be equipped with ample means of pressure relief and be offset not less than 15 feet from the nearest side of the mine opening; or
2. Be directly in front of, or over, the mine opening; however, such opening shall not be in direct line with forces coming out of the mine if an explosion were to occur. There shall be another opening, equipped with a weak-wall stopping or with explosion doors, that is located not less than 15 feet or more than 100 feet from the fan opening and in direct line with the forces coming out of the mine if an explosion were to occur; and
3. In a mine ventilated by multiple main mine fans, incombustible doors shall be installed so that if any main mine fan stops and air reversals through the fan are possible, the doors on the affected fan automatically close.
D. Each main mine fan shall be provided with an automatic device to give alarm when the fan slows down or stops. Unless otherwise approved by the Chief, such device shall be placed so that it will be seen or heard by an authorized person.
E. Each main fan shall be on a separate power circuit, independent of the mine circuit.
F. The area surrounding a main fan installation shall be kept free of combustible material for at least 100 feet in every direction where physical conditions permit.
G. Each mine fan shall be operated continuously except when no miner is underground and such mine fan is intentionally stopped for necessary testing, adjustment, maintenance, or repairs, or as otherwise approved by the Chief. If the main fan is intentionally stopped for testing, adjustment, maintenance, or repairs, the mine operator shall comply with the requirements set forth in the approved fan stoppage plan for that mine. If the main fan is stopped after all miners are out of the mine, the fan shall be operated for a period specified in the approved fan stoppage plan for that mine, prepared pursuant to § 45.2-834, before any miner is allowed underground.
H. Where electric power is available, no main mine fan shall be powered by means of an internal combustion engine. However, if electric power is not available or the fan is employed for emergency use, a main mine fan may be powered with an internal combustion engine. Unless otherwise approved by the Chief, such fan shall be operated exhausting and the engine operating such fan shall be offset at least 10 feet from the fan and housed in a separate fireproof structure.
Code 1950, § 45-60.1; 1954, c. 191; 1966, c. 594, § 45.1-54; 1978, c. 120; 1988, c. 597; 1993, c. 442; 1994, c. 28, § 45.1-161.216; 1996, c. 774; 2005, c. 3; 2011, cc. 826, 862; 2021, Sp. Sess. I, c. 387.