The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1909-01-30
SAFETY OF SHAFTS SUNK THROUGH IT
WHEN cAvING STARTS
SUGGESTS MUCH sIANOplplNG
A Marquette Range Mining Man Advoeat-
ed Putting Down Many Pipes to
Determine Ledge.

.What is going TO be the result to
shafts sunk through the deep overburden
when caving Of the ore body com
mences' inquired Diamond Drill
reporter of a Marquette range mining
man who is now up against the prob
lem.
nWell that is a question that have
given n great deal OF thought to and
ALI can say on tne subject is to tell
Won what have done in order to avert
any disaster from that source.
ssMy people have several deposits OF
ora living under deep quick sand over
burdens, /" said he AT some OF these
properties the first shaft was sunk
without giving that question much
consideration but now we are studying
IL very carefully.
~ am a great advocate OF stand
pipes 10 determine the nature OF the
ledge and my plan has been to sink a
great number of stand pipes In all dir
ections. first to determine the probable
boundaries Of the ore deposits and Sec
ondIy 10 determine IL any other ore de-
posits lie In the immediate vicinity.
"a stand pipe don't cost very much,
when compared with the cost OF sink
ing a shaft through such stuff One
shaft lost by being located in the
wrong place will pay for many, many
stand pipes.
Shaving satisfied myself as closely
AS II is possible TO determine, the
probable boundaries OF the ore deposit
/ then locate my shaft at sufficient
distance 80 that the pulling OF the
sand will not reach the shaft, figuring
one and one-half TO one.
This problem OF the effect Of caying
he mines with heavy overburdens viii
soon be live one on the west side OF
this county where the overburden is
anywhere from 100 to 300 feet, all OF II
quick sand None Of the properties
so handicapped have yet arrived at
that stage 30 that an actual demonstra-
ton of the effect can be had.
II is probable that the big Caspian
will be the first one 20 calculate from
as the operators are already squaring
around TO make the first drop.
This property has an overburden
that will average somewhere about l2O
feet. 1t is mainly quicksand and what
Ia not quick sand is kindred material
that will rnu as freely as the sand
itself.
One of the shafts Is very we'll located
to Withstand the pulling by the sand.
being located at quite distance from
the ore body. The other is closer to
the ore.
La order TO lessen the difficulty the
operators bave drained this huge body
OF everything sand in a very ingenious
manner
They located sub-leyel ten feet be-
low the ore and from those sub-drifts
short raises were put up to the sand.
close enough TO allow the water TO seer
through freely but careful not 70 let
the sand In
In this manner the water was at
drained out Of the sand TO the firtt
level where big pumps hoisted It tc
surface This draining process took
about years time and is now com
pIeted A test shaft was put dowr
over the ore 10 water and as fast as the
water level dropped the shaft was con
tinued down with ease until IL finally
was holed through into the sub-level.
The ore is being taken out of this sui
~ fast as possible and the floor carpet
cd with tagging when the timbers viii
be shot out and the dirt above al
owed 10 cave down.
II will be a couple Of years yet be
fore sufficient sag is made to allow
OF much observation be made as q
the effects upon the shafts but the pro
gress will be watched with interee
ard much knowledge gained there
Mm.