The Roanoke times. [volume] (Roanoke, Va.) 1890-1895, 1892-12-26
"ELECTRIC MINING
AS Applied to tho Operation oflBltumin
ousaCOal Mines

In mining coal ono of the problems that scri-
ously Affects the cost OF production Is to get (
down. Some operators permit shooting Off the
solid resulting in nearly every case exceptions
OF course) In some costs and II there may happen
to he lump OF considerable size close insnnction
or exposure to the weather will show IL to be
badly shattered and unit for handling as hmm
the so called screened lump being little better
than mine run. This Is not the only evil resuit
from such methods OF minn !; in many eases
80 much powder is used that the ribs are shat
tered, top broken and rendered unsafe, props
knocked down and broken, coal scattered so that
a COM ibcrable portion is never recovered. An
other very bad feature OF solid shooting is the
powder ,moke, which makes IL difficult 10 nrnn
e CITY vsnnlate the mine and necessitates the
firing NJ liked honrs. As showing that the evils
are known and in somc cases guarded against
inc following convcrs ltion with Il prominent
do your mines shoot or the solid:' Promi
ncnt operator YES: - blcs. them il Won don't
watch them" Writer What do Won do vha,
you catch them 50 doing:' ,'rominsnt on.rat,
Discharge them nj once rs they know , mr. rules
pr hibit solid shooting"
Some operators. believing tina. this IL the
cheapest method OF miLinE (and in this day md
age cheap coal is what il wanted) have eouinncd
their their miues with compressed mir and electric
power To do their drilling. With the improyrd
poSer drills of the various makes a man and II
boy can drill a1ont sixty to eighty holes per day
OF ten honrs. The p:ac zeal operator will see ut
glance that it Is better to drin by machinery
than 1t is by hand, but II the other objections To-
solid shooting will hold cool The operator
who wants to put his coal on the market I'm the
best condition and chcaply IA possible realizes
that tho old fashioned methods OF mining must
ba abandoned 20 great ext mt and the most
approved machinery introduced TO undercut
inc coal, to drill II, to haul II, to scream and
thoroughly separate he various sizes NJ lump
nut, pea and slack. How can the coal he chcapiy
and successfully nndercut. How will we get the
power 10 the machines! Can we depend upon
1t! Is machinery In mines an experiment. These
are the questions that maturity arise When in
vestigating this subject Will take the case of
mine the writer hts in view. Roo us twenty
'onr foot wide, coal four and half feet In
height, miner will he two or three days taxing
a four feet slice Across the face. reasoI ABLY
good mbing machine viii undercut the same
room nye feet every day. or with the machiue
y0r Will be able to Two three foot slices in
the same Inc IL takes the miner with his nick
10 give You ono four foot slice There are some
makes or machines that will undcrcut fifty TO
sixty feet face hrco and half tn four and I'M n
feet deep per shat. some other max Cd viii do
eighty to lN feet, five to ak feet deem The
labor required to operate either machine IL the
ne governed by Xisting conditions IA that Iyuc
OF machine which will give tho hest results il,
Que mine would he useless in som others INC
constructing engineer has several " pes of minin.
machines 10 select from ind Ouli pol -, very ~
ants We have he comprc. sed aIr 10 rch,s,.
mining machine ri mt least two different ma -
the electr cll percussion machine OF Two I, ne.
the Sol mold AMI traeiive spring; then II .cn !
| the rotating cutter hlr onl tho two or the ,
chain cuitcrs. ~ showing that tho u,e az ,hr ,
marhiues Is not exnesiMcntal tho w.iter w0VlI