Report of the Bureau of Mines of the Department of Internal Affairs of ...

No. 10. SEVENTH ANTHRACITE DISTRICT. 193
and IS landing oil steep aiigles liom 4U degrees up to 80 degrees. Mr.
Williams discovered, by experience, that unless some new method of
robbing the pillars in these small seams on such steep angles could be
successfully adopted, that the life
short duration.
of this model plant would be of
In order to prolong the life of this colliery as long as
possible, which would be a benefit to the land owners, the operators
and the working men as well as the community at large, Mr. Williams
was determined to try a new method of robbing the pillars in small
seams on the heavy dips so that 90 per cent, of all the coal in place
could be taken out. His method is thoroughly explained on the ac
companyiug sketch. The pillars in the upper seam are taken out
first; the breasts in that seam are driven up within a reasonable distance
from the surface, enough coal being left against the surface to
keep it up until the final robbing; after the top rock has subsided
below this point, the balance of this coal is buggied to one of the
breasts which is used as a counter chute. Whenever practicable,
every fourth or fifth breast is driven through to the surface; this opening
is used by the men, through which they bring down timber
for propping the breast, also the place where the pillar stood.
soon as everything is ready to commence on the pillars, the loose coal
in the breasts on either side of the pillar is withdrawn, leaving a
space of six or eight yards in length at the top end of the breast.
Props are brought down from the surface, through the openings already
mentioned, and put up in the open space in the two breasts,
one on either side of the pillar to be taken out. These props
are put up five or six feet apart, as circumstances reciuire.
If there is a bad, loose bottom under the seam, every other prop is
extended through this clod; the other prop is put up on top of the
clod. By so doing, the bad bottom is prevented from slipping and
mixing with the coal. This is very important where small, lean
seams are mined on steep angles, as everything which is loose in the
breasts has to be loaded out and sent to the breaker, making it very
troublesome and expensive to prepare the coal. As soon as the space
in the two breasts, which I have just mentioned, is propped and secured,
we are ready to start on the pillar. The miner puts in a light
charge of ]>owder and fires a blast in the ]>illar close to the face of the
breast which he has secured with props. This blast loosens the coal
in the pillar so that the miner can release a large quantity of it with
his drill. The pillar coal worked in this way ])ioduces 2.o i)er cent,
more i)rej)ared sizes than the breast coal, which is quite an increase
to the interest of the land owners as well as the coal operator. As
soon as this section of the i>illar is taken out and the space where it
stood is properly pro]>]»ed, we are now ready to proceed with anolher
section. The coal in the two breasts is withdrawn again for six or
eight yards; the breasts are propped and secured; then we start on
i;^,—10—07
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