The Oklahoma City times. [volume] (Oklahoma City, Okla.) 1908-1984, 1917-09-26
CONSERVATION OF COAL
AND ASPHALT THE PLEA
FOR SALE OF DEPOSITS
Continued From PAGE t4A

Continued From Page ~
sometimes they are as much as 50 fee,
and as they are extended back. they. too.
are supplied with break -,hroughs con
meeting with the next adjoining room.
Pillars, approximately the size OF the
rooms, are left between TO sustain the
roof
More Than Half Coal Lost.
In some places where the room aud
pillar system is used the pillars are
pulled out after the rooms have been
finished but that plan is seldom at
tempted III Oklahoma mines Men Of
long experience IN mining in Oklahoma
estimate that the recovery OF coal from
the scam varies from IS to "a percent.
the latter amount being realized only
IN exceptional instances. The remain
der ithe coal or that left as sustain
ing pillars, Is irrctrleyably lost, since
the expense OF recovery is so great,
after a mine has been worked out, a.
to make the mining OF it prohibitlve.
Few Try Better Plan.
The most approved system OF mining,
in fields where the seams are more
level, is known as the long wall system.
| That system is used exclusively in
Scotland and, in the opinion OF Okla
homa mining engineers, can be made a
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. As each
man has only a small length of face
to work, he keeps up two or three feet
OF these pack walls and fills in between
them with COB, The theory OF the sys-
TEN is that the roof will not break of
at the face, bu, will gradually subsidc
behind these pack walls, exetting a
uniform pressure along the face Wher
the coal is undermined this pressure
causes the coal 10 fall so that few il
any explosives are necessary In this
respect long wall mines are considered
safer than room and pillar where large
quantities OF explosives are used Whcr
the pack walls along the entries ar,
squeezed down il is necessary 10 tax,
down more rock along the top OF tho
entries TO gain height This operation
is continued at times until the pack
walls are squeezed absolutely together
Long Wall Is Success.
The modified long wall proposed tor
the Oklahoma field is either a retreat
ing system. where the slope is driver
TO the bottom Of the prospective work
ings then the coal pulled out as III,
workings come back, or panel system
whereby the coal area is divided b,
criss-crosS entries and the coal is wol
from the panels by long wall method,
!, BY either system all the coal would b,
recovered The tetteating system woul,
have the advantage OF leaving boil
danger and water collections alway
below the workings but would ncceSSi
tate the expenditure of large sums o
: money in opening the mine
The Folsom. Morris company opctat
, ing mines at Midway. is cxpcrimen,in
with the old Scotch system oi advanc
, ing long wall and the Rock Island Goa
, Mining company m ITS mine No 5 a
t Anderson, IS trying the panel system
| Both are said to he meeting with sur
; prSing success. The Folsom Morn
, companyS experiment IS IN a three
S foot vein Of coal and the working owe
| Of a partially opened room and pilla
I mine
{ It IS claimed by mining engineer
that the long wall ey,,cm will do ava
{ with from Is to 2S pcrccnl of the pre-,
I cnt cost oi operation hy clmnatiu
prdapc and much Of the dead wor
, and materially reducing the number d
iay w,0 under the present system. ou
. hy man ia muloy,l '1r every w
COAL d'ggr, Furthermore II wou'
wcau the recovery OF from 20 to ~