Northern Wisconsin advertiser. [volume] (Wabeno, Wis.) 1898-1925, 1902-08-07
COAL CUTTING BY MACHINERY
The Two General Types of Machines.
Nov in Use.

The TWO General types VI "aS
Nov in Use.
Casters EzEazine.-The two gen.
eral types of coal cutting machines
in most common use in the mines OF
The United States may be classed
under the heads of pick or punch
ing" machines. and the 'chain breast,
although a few 'longwalF' machines
are in successful use in some or the
thin seams of the western states.
The method of mining in America is
usually some adoption OF the pillar
and-room" or ''stall-and-pillar' sys-
TEN, and most of the lougwall ma
chimes made in the United States are
shipped to Europe, where that system
of mining is generally practlced.
There are in the United States,
seven extensive manufacturing es-
ts-s lishments making specially OF
coal mining machinery. Three OF
these make pick machines and four
manufacture chain cutting machines.
These types of mining machines nave
been brought to such degree OF
efficiency that, it is safe to say, there
are comparatively few bituminous
coal mines, operated upon an exten-
sive scale, that could not with advan-
tage be equipped with mining ma
chimes There is but one adverse
condition that has not been success
fully surmounted and that is the in
clination of the vein when the dip
exceeds IL or Is degrees. Some OF
the pick machines have been used in
mines where the inclination was as
much as % degrees; but the work
was slow and difficult and it was
only from the fact that the price of
labor was high that the machine was
able to compete with it. The trouble
does not lie so much in the actual
cutting, but in the difficulty of NOV
| ing the machines from place to place.
Manufacturers do not care to run
the risk of failing, and prefer not to
install machines where the dip ex-
ceeds, say, IA degrees. By the use OF
self-propelling trucks it has been
found possible to use chain machines
in mines having this amount of in
clination from the horizontal; but
that is about the maximum. The
self-propelling truck also enables the
chain machines to be used in mines
where the seam is SO thin that it
would be otherwise impossible to
draw the machine or move it up to
the face of COAL as neither horses
nor mules could go into the room I'M
less some of the floor were taken up
or the tcr taken down.
All of the pick machines in success
full operation at the present time are
driven by compressed air, although
one company claims to have develop
ed an electrically-driven pick ma
chine which has overcome the me
chanical difficulties heretofore effec-
tive against the use of any other
than an air-driven pick machine
Most of the chain machines and all
of the few longwall machines in
American use employ electricity as
motive power. In some of the long
wall machines of British make COM
pressed air supplies the power In
some mines where gas is present in
dangerous proportions, and is apt to
be exploded by an electric spark, or
where other conditions are against
electric installation, chain machines
operated by compressed air are in
use. One of the principal objections
offered to the use of air for chain
machine is the low temperature pro-
duced about the legs of the operative
by the expanding air from the ex-
haust. This cold is sufficient to cover
| the exhaust pipe with frost and to
produce rheumatism in the miners
legs.