The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1919-05-08
HOLDING 0SBURN FAULT
N THE KELLOGG TUNNEL
CONCRETE ARCH WILL HOLD
MASS OF RUNNING GROUND
WORK DESCRIBED.

lion, the publication issued at irregu-
lar intervals by employees Of the Bun
ker Hill & Sullivan company, con-
concrete work that is being done in
the Kellogg tunnel where it passes
through the Osburn fault. The story
is told by Max G. Richardson and
here follows
Bad Piece Of Ground.
1t is quite generally known that
when the Bunker Hill mine was run
in 1900-1902, a great deal of difficulty
was experienced in passing through
what is known as the Osburn fault.
Two, at least, of the men who worked
all through that strenuous piece of
tunneling, are still on the Bunker
Hill payroll, j. w. Jarrett, who is now
night watchman; and Willard Fur
bush, who subsequently worked for a
long time in the mills and who is now
an operator at the smelter.
Just prior to hitting the fault pro-
per these men tell of some hard
breaking ground which was so short"
that it stabbed off badly and had to
be timbered up very quickly. Then
some soft, talcy ground was encoun-
tered and this had to be handled by
the spiling method According to
Jarrett, one day shift crew got about
ready to put in set of timbers; the
night shift had so much difficulty
placing the set that they finally put
the cap upon post which was a
foot too short In endeavoring to
change the post the next day. the
fault broke out, pouring a mixture OF
quicksand and water under pressure
with such force that the stream shot
clear across the tunnel and would
tear the skin from a hand held in its
course.
Move Much Muck.
No one seems to know the exact
number of cars of muck taken out of
this one set, but all agree that 1t ran
into the hundreds and that 1t took al
most 80 days of constant work and
desperate attempts before the next
advance of five feet was made and the
next set finally placed. Six by six
inch timbers, IL feet long, were used
as spiling for the sides and roof and
were driven in by hammer made of
a big sprag pole having three bolts
running crosswise through it so that
six men could swing it to the spiling.
Face boards were used and all cracks
in the rock were wedged tight with
shingles.
Subsequently as new timbering be-
came necessary new posts and caps
were put in between the sets already
in place until at the present time
there is an almost unbroken row Of
sets for quite distance with no
room for further reenforcements. In
the many years that have elapsed
since the fault was broken into, the
water has been thoroughly drained
cut and it is anticipated that no very
great difficulty will be experienced in
opening up above the tunnel sets by
regular spiling operations, using ex-
-traordinary care to prevent a run
which would tie up traffic in the tun-
mel and thus force the mine to shut
down. Consequently, Mr.. Easton de-
cided to put concrete arch under
each of the worst places. Three tim
bermen, J. NJ Erickson, Arnie Samo-
IL hal yIytt l.
lowing assistants-Paul Kalopet, Sill
as Smith, WI H. and Clifford Caug-
hill, have been at the work for some
time Three caves running from 80
to go feet in height above the tunnel
sets, have been caught up; some very
bad ground has been held in place by
spiling and breast boards; and angle
posts have been set outside the tun-
mel sets to take the load off the old
timbers Several new tunnel sets
have been set in place and at the
present time concrete walls and
arches are being poured in a 5O-foot
stretch Of bad ground which has con-
siderable weight and has a tendency
to run. Inc OSDuTH ldull ioS Ao'
been tapped yet, but Erickson, who
has the timbering in charge, feels
confident that it will not occasion
much trouble this time.
How It tls Being Done. s...
The first step in concreting Is the
placing of 6x1O-inch helper posts as
close to the track and air pipe as may
be possible, and then the re-
moval of the old posts. The muck
etc., is then cleared out about two fee
below track level or until solid bot
tom is reached. Wall forms are bull
close behind the helper posts. leav
ing at least IS inches width of room
for concrete outside them. Thes'
wall forms are extended up to tn
top of the old caps. Arch ribs, cut II
radius which will give one par
raise to six feet of span between tn
walls, are thrown across and brace'
OH five rows Of stringers running
lengthwise above the caps The wal
rooms are both poured full OF con
crete and then each side Of the arch
leaving above three feet in the cente