1396

LAWS OF MARYLAND

Ch. 418

(o) (1) Provisions Governing Handling, etc., of
Explosives Applicable. The provisions governing handling,
storage, and transportation of explosives apply to the
heater elements of a cardox blasting device prior to its
installation in the shell.

(2) Transportation and Storage Underground;
Conditions When Used for Blasting. Any charged cardox shell
shall be transported underground in an insulated car or
insulated box placed in an ordinary mine car. It shall be
stored on wooden racks, built for that purpose, in a
crosscut or an idle room neck, at least ten feet from any
power line and haulage track. Where cardox is used for
blasting, the following rules apply:

Rule 1 — Cardox shell does not have to be tamped or
stemmed.

Rule 2 — When cardox is fired, every person in the
vicinity, including the shot firer, shall be around a second
corner or in an equally safe place.

Rule 3 — Blasting cable shall be as long as necessary
to assure the safety of the shot firer, attached only after
the charge has been placed in the borehole and maintained in
good repair.

Rule 4 — The charge may be detonated with a
permissible shot-firing unit.

Rule 5 — Cardox may not be shot off the solid, over
heavy rock binders or shale, or in a "tight" shot.

Rule 6 — Any cardox misfire caused by the failure of
the disk to rupture may not be approached until after a
waiting period of at least 15 minutes. A mine foreman or his
designee shall supervise the handling of the misfire. The
misfired shell shall be bled off before removal from the
hole, and marked conspicuously on removal from the hole.

(p) Where airdox is used for blasting or breaking down
the coal, the following rules apply:

Rule 1 — Compressed air shall be conducted from the
compressor to within a practical working distance of the
face by a steel air line tested to withstand an approximate
pressure of 20,000 pounds per square inch.

Rule 2 — Air lines shall be grounded at the compressor
and, if possible, at other low-resistance ground connections
along the lines, such as at bore-hole casings. They may not
be connected in any way to any track, water line, or other
electric power return conductor. They shall be suitably
insulated where they cross electric wire or underneath the
track.

Rule 3 — Unions shall be installed in each steel air
line at not more than 1,000 foot intervals.