Air locks; overcast; undercast; doors
Sec. 7. (a) The ventilation shall be so arranged by means of air
locks, overcasts, or undercasts that the passage of trips or persons
along the entries will not cause interruptions of the air current;
however, when air locks are impracticable, single doors may be used.
Where single doors are used, they must be attended constantly while
the section of the mine controlled by such doors is in operation,
unless they are operated mechanically, except that doors in or
between panel or room entries need not be attended if all persons
who pass through such doors are instructed to close them promptly.
Air locks shall be ventilated enough to prevent accumulations of
methane therein.
(b) All doors used in guiding and directing the ventilating currents
shall be hung and adjusted so as to close automatically.
(c) Overcasts and undercasts shall be constructed tightly of
incombustible material; they shall be of ample area to pass the
required quantity of air and shall be kept clear of obstructions.
(Formerly: Acts 1955, c.168, s.55.) As amended by Acts 1979,
P.L.231, SEC.11; P.L.231-1983, SEC.16.
Last modified: May 27, 2006