San Antonio light. [volume] (San Antonio, Tex.) 1911-1993, 1924-03-30
BUREAU OF MINES CLAIMS
LIFE TOLL in EXPLOSIONS
CAN BE GREATLY MINIMIZED
Urges Use of Rock Busting Methods Found to Be
Efficient in British and French Coal Mines,
Claiming That 1t Is Less Expensive Than
Watering and Much More Dependable.

4 Explosions of coal dust such as hav
censed a toll of hundreds of lives il
American mines within the past few
months can be greatly minimized b,
proper rock busting methods, state
the Department of Interior, which re
Gently commissioned George s. Rice
chief mining engineer of the burea,
of mines, to make a study of the us,
Of these methods which are in us,
to prevent the propagation of coal dus
explosions in European mines. Tn,
rock dust is spread upon the floor
roof and sides of passageways oil
place. upon specially constructed bar
riers, and when stirred up by the con
cussion OF local explosion, forms q
screen which prevents the flame OF
the explosion from propagating be
yond the immediate area of origin.
Stone busting as means of limit
ing coal dust explosions is made com
ruisCry, by governmental regulation
| in 1Ioat Britain. except In anthra'
cite mines and in bituminous mines
that arc naturally wet throughout. A
great many British mines of large ca
pacity cave used rock dust for more
than ten years. The majority of Brit.
ish mines for the last four years and
practically all mines for the last two
years nave been using stone dust. No
coal dust explosions have occurred or
have been propagated in any part OF
a mine that has been thoroughly stone
busted, whereas there have been a
number of explosion disasters in re-
cent years in British mines where the
coal dust watering method was prac-
ticed or in certain parts Of mines
which were supposed to be so wet
naturally that they lid not need stone
busting. In France, tie scene in 1906
Of the greatest of all coal mine cx-
plosions-the Courrieres disaster.
which killed HOO men-the practice
of Iock busting prevails in certain
districts. and French officials are urg-
ing d wider use of rock busting in the
more dangerous mines.
Although the bureau OF mines has
urgently recommended rock busting,
only n few operators in the United
States have adopted the practice. Oper-
ators of mines in southern Illinois
that have installed rock dust barriers
state that these have prevented many
coal dust explosions from extending
beyond the location of the barrier.
Other operators of mines where dis
astrous coal dust explosions have &C.
CURED. in spite of precautions taken
to keep coal dust thoroughly damp
ened, are now considering the adop-
ton of rock busting.
Tests Confirm Judgment.
Great Britain in 1908. and France
in 1907, after the terrible Courrieres
explosion, began to make coal dust
explosion tests. Investigators in these
countries concluded that enough in
combustible dust spread through n
passageway charged with coal dust
prevented the propagation of an ex-
plosion by the coal dust. Rock dust
ing was early tested with success by
the bureau of mines in a steel testing
gallery at Pittsburg and, beginning in
1911, at the bureaus experimental coal
mine Mt Bruceton, Pa. Several of the
first publications of the bureau suggest
cd that rock dust used in gaseous or
dusty bituminous mines. Since that
time additional tests in the expert
mental mines have fully confirmed this
first judgment.
For three years-191S, 1919 and
1920-the United States was comlnr-
atively free from disastrous explosions
in bituminous and Ignite mines. In
these three years. Al, 81 and AZ men.
respectively, died in explosions that
killed five or more men, as contrasted
With the years 1001-1910, in which an
avefage Of $50 men were killed annu-
ally. This good record tended to pre-
vent mining men from seriously ques-
tioning the effectiveness of coal dust
watering methods as generally prac-
ticed under careful management in
naturally dry bituminous and Ignite
mines. Between January /, 1918.
and December 81, 1923. however. there
occurred nineteen explosions, in six
teen Of which coal dust was consid-
cred to be the propagating or con-
tributing agent; and in these explo-
sions $50 lives were lost. Already in
1924, at johnson City, H.; Shank
town, Pa, and Castlegate, Utah, mine
explosions have cost more than 200
lives. The fact that the watering
method was either used or supposed
to have been used in these mines has
convinced engineers of the bureau of
mines that the watering method ia
not reliable, and that the compare.
tive immunity from disasters during
the three years just mentioned was
partly due to good luck, since a COM
bination Of circumstances is necessary
to produce a dust explosion, and part
ly to better methods of preventing
the ignition of gas and coal dust
through the adoption of permissible ex-
plosiyes. permissible miners lights,
and other approved appliances.
Watering Seldom Well Done.
American mines have heretofore re-
lied on watering and the prevention
of ignition to avoid coal dust explo-
sions. Although it is agreed that
watering is successful if done with abb
solute thoroughness, engineers of the
bureau of mines have rarely. il ever.
found watering so perfectly done that
IL a source of ignition was present
in imperfectly watered parts of the
mine coal dust explosion would not
follow. This conclusion does not APP
ply TO Pennsylvania anthracite mines.
the dust Of which has not been found
to be explosive, but does apply to all
bituminous, semi-bituminous and sub
bituminous coal mines. Especially in
the cold dry months, watering is ef-
fective for only a short time after il
has been done. because the air cur
rent rapidly dries the coal dust. Tests
L. Il ~