1372

LAWS OF MARYLAND

Ch. 418

A person may not travel on foot to or from his work on
any slope, plane, or haulage road, unless no other road is
provided or available for that purpose, and then only when
permitted by the mine foreman. No person, except an official
or a repairman may travel on slopes or planes while cars are
in motion on them.]

[7-424.

In any mine wherever the condition of grade, weight to
be moved, and distance of movement, or any of them, render
the placing of mine cars liable physically to injure the
miners if they are required to place the cars by their own
exertions, the Bureau by rule or regulation may require that
the cars be placed at a convenient location in the heading,
room, or other excavation point where the miners are at work
so the cars need not be moved further.]

[7-425.

(a) (1) Installation and Equipment. Each mine shall be
ventilated by a main fan installed on the surface in a
fireproof housing, situated not less than 15 feet from the
nearest side of the mine opening. It shall be equipped with
fireproof air ducts and ample pressure relief or explosion
doors. However, in a mine where the air is of a purity that
it contains at least 19.5 percent oxygen and not more than
0.75 percent carbon dioxide, a fan is not required. If the
bureau determines that the purity of air is below these
standards, it shall order the installation of a fan or other
mechanical device to insure the purity of the air. An
existing fan that is offset any distance from the mine
opening need not be moved if it otherwise complies with the
provisions of this subsection.

(2)  Alternative as to Location. Instead of
locating the fan and pressure relief or explosion doors, as
required by paragraph (2) of the subsection, the fan may be
directly in front of or over the mine opening, if the
opening is not in direct line with possible forces coming
out of the mine if an explosion occurs. If there is another
opening having a weak-wall stopping or explosion door that
would be in direct line with the forces coming out of the
mine if an explosion occurs, the opening may not be less
than 15 feet nor more than 100 feet from the fan opening. No
main fan may be placed inside any mine.

(3)  Reversal of Air Flow; Alarm When Fan Slows
or Stops; Fan in Gassy Mine To Be on Separate Circuit. Every
mine fan shall be installed to permit the reversal of air
flow and, unless the fan is attended constantly, an
automatic device to give alarm when the fan slows down or
stops. This device shall be placed so that a responsible
person can see or hear it. The fan of a gassy mine shall be
on a separate power circuit, independent of the mine
circuit.