The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1906-09-24

but also the geology Of each level is
shown on it in different colors Tho
scale of this model is also fifty feet
to the inch The ore body is opened up
by FIVE tunnels. The shortest OF these
is the uppermost, No. 3, which is 10
feet long, while the lowest, No. Z, is
1900 feet long. No. 6 tunnel is 100
feet above No. Z; No. ) Is 100 feet
above No. G; No. is so feet above
No. ,; and No 3 is 100 feet above No.
4. No, is now used for main work
ing tunnel, and all the ore is sent by
chutes down TO this level, where 1T is
loaded into trains OF six cars holding
two tons each and hauled by mule, or
horse. to the bins of the receiving sta
tion of the tramway. These cars arc
run by two men from the different
chutes to the switches where the trains
are made up. Horses are also used on
the No. level to haul the ore IN trains
of eight one-ton cars from the Tar
chutes TO the cbutes going down to NO.
level, A winze has been sunk 100
feet below No. level and some ore has
been blocked out there. Considerable
development work is being done
throughout the mine, but most OF IT Is
being done upon No. 8 and No. levels,
while most Of the ore being mined
comes from above No. ..
System of Mining.
The orc is mined by the square"set
system, the sets biug carried up from
the level below to the one above; In
a few cases, where the ore body is
adjacent TO slopes which nave caEsu
to surface, and where consequently the
ground is rather heavy, a mobilization
Of the square-set system is used. In
the ordinary squareset slopes several
sills are Jagged with split twolnch
plans. which are then filed with waste
obtained from development work; the
whole mass Of the ore body is mined
there being no waste IN 1T. These 1iiled
cribs steady the slopes sufficiently so
that the slopes do not have to be filled
completely OF course manways and
| chutes are carried up occasionally In the
| ssts. Angle braces made from 6xlo-
| inch sticks. or else from round tlmbers,
are used in some places to brace. the
! sets when they begin to take weight,
| These sets are the same as those at
| the Boston Consolidated mine, being
| five feet square, centers. and seven feet
four inches high, centers. Iwo-lnch
plants are used for floors.
If the slopes are heavy, as when near
caved Slopes or near the surfaces, the
following method is used: sill rs
driven in fifty feet below the top OF
the stope. A line of square sets IS car"
ried clear into the end of the ore body;
then n line of sets is carried across the
stope and then floors are carried up
to the top Of the ore. AS soon as the
ground begins to be heavy the posts. Of
| The sill set arc blasted out. by loading
and firing auger holes bored into them
and the ground above is allowed TO
cave. Then the rest Of the block OF
ground is mined as before. When one
Of these blocks, fifty feet thick, has
been mined out and caved, they go
down the raise fifty feet. and begin on
the block below in the same way. Rand
drills 31s inches, are used IN driving
the drifts. Two-inch Rand drills and
2M inch Sulhvans, mounted on tripods
are used in the Slopes. Wheelbarrows
or small scoop cars on tracks are used
TO oct the ore 10 the chutes. The break
ing OF the ore is all done by contact
Stopping costs 50 per set for Sill sets, and
$3.50 per set for upper sets, including
| placing the timbers. Drifting costs
$3.50 per set for upper sets, including
putting in timbers when required: Ibe
company does the shoveling and fur
nishes the powder, drills. machines, ETC.
but the miners have to put in the tim.
hers, The miners arc guaranteed So
per day. Muekers and trammers arc
paid $3.50 a shift. The company also
has timbcrmen paid So to $3.50 shift
who keep the slopes IN shape. There
are 325 men employed in the mine aud
on the tramway.
| o,mu>-rODruy STocr RROr.