WM. PRESTON LANE, JR., GOVERNOR. 1073

2. Clearance requirements shall be the same as those
for transporting men on belts.

3. Suitable loading and unloading stations shall be
provided.

4. There shall be an attendant at loading and unloading
points and stop controls at these points.

(d) Explosives or detonators shall not be transported
on flight or shaking conveyors, or by scraper or mechani-
cal loading machines.

147. Underground storage, (a) Where underground
section boxes or magazines are used they shall be of sub-
stantial construction and placed in a crosscut or idle room
neck at least 25 feet from roadways or trolley wires and
in a reasonably dry and well-rock-dusted place; the ex-
plosives and detonators shall be kept in separate boxes or
magazines, or if kept in the same box they shall be separ-
ated by at least a 4-inch substantially fastened hardwood
partition or the equivalent. Nor more than a 48-hour sup-
ply of explosives, including any surplus remaining from
the previous day, shall be stored underground in such boxes
or magazines.

(b) Explosives and detonators kept near the working
faces shall be stored in separate closed containers of sub-
stantial non-conductive material located not less than 15
feet from rail or power lines, except that if kept in a
niche in the rib, the distance shall be at least 5 feet, and
in a location out of line of blast where they will not likely
be subjected to shock.

(c) Explosives and detonators shall be kept in their
containers until removed for use at the working faces.

(d) Only nonmetallic tools shall be used for opening
containers underground.

148. Blasting practices, (a) In all mines, for the blast-
ing of coal or other blasting operations, permissible ex-
plosives or permissible blasting devices shall be used ex-
cept as hereinafter provided for. The use of permissible
explosives shall comply with the following:

1. Fired only with electric detonators of proper strength.

2. Fired with permissible blasting units unless blasting
is done from the surface.

3. Boreholes in coal shall not be drilled beyond the back
of the cut, nor into the solid rib, roof, or floor; shooting
off the solid is hereby prohibited.