Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1916-10-02

the drilling Of 4 hole into the face of
the coal and the blasting Of the coal
off it's bed In much the same way as
rock Is blasted in the quarry, no un-
dercuttlng or overcutting being done,
and very little sharing. As black
powder is almost always used for
blasting coal in this state. government
experts say there is every condition
present that Is apt to cause trouble in
n mine, az the coal makes fire dust,
there Is gas present in many cases and
generally the shots are overcharged.
Black powder IL is explained. gives
off "A long flame and this flame ignites
any gas or dust present and causes an
explosion. The bureau Of mines. for
these reasons, has been advocating the
use of permissible explosives, accom-
panied by the practice of undercut-
ting. Uvercutting or sheuring Be
sides the danger in careless use of
the black powder, it is said, this sys-
tenn Of using II In shooting off the
solid produces an undue amount of
fine coal and unnecessarily reduces
the amount OF lump. on which the
profits OF mining are based.
Install Electric system.
An order OF the bureau of mines
for the exclusive use of permissible
explosives or the shooting of blasts
miners and operators, because of the
expense, but several mines in this
field have installed the electrical sys-
TEN OF firing shots and in some places
the permissible explosives are volun-
tarily being used.
The most approved system of min.
ing, in fields where the seams ars
more level than they are in Oklahoma
is known az the long-wall system
| NTN1N. H.aIt
Scotland and, in the opinion of Okla,
homa mining engineers, can be made
success, on "A modified plan, in this
field
In long wall mining all of the coal
is taken out in the first operation. In
working the coal main entries are
kept open by shooting down the top
rock and building pack walls along
/ the side OF the entry that is kept open.
Az each man has only q small length
| OF face TO work, he keeps up two OF
! three feet OF these pack walls and
fills in between them with COB. The
| theory of the system is that tho root
will not break of at the face, bu,
will gradually subslde behind these
| pack walls, exerting a uniform press
ure along the face. When the coal Is
undermined this pressure causes the
/ coal to fall. so that few II any eX-
piosives aro necessary. In this respect
| long-wall mines are considered safer
than room and pillar. where large
quantities of explosives are used.
When the pack walls along the entries
are squeezed down 1t is necessary to
| take down more rock along the top OF
the entries to gain height. This opera
| tion is continued at times until the
pack walls are squeezed absolutely
together.
The modified long-wali proposed sor
the Oklahoma field Is either retreat.
ing system. where the slope is driven
to the bottom OF the prospective work.
ings, then the coal pulled out as tho
workings come back. or a panel sys-
tenn whereby the coal area is divided
by criss-cross entries and the coal 10
won from the panels by long-wall
methods. By either system all the
coal would be recovered The retreat
Ing system would have the advantage
OF leaving both danger and water col.
lections always below the workings.
| but would ncccssltate the expenditure