Mining terms
Anyone who spends time in and around old mines should
learn some mining terms. Some of these are best explained
by illustrations, but I will do what I can with words:
- tunnel
This is what everybody calls any horizontal mine opening,
but in truth it is only a tunnel if it goes in one place
and comes out another, i.e. if it is open on both ends.
- adit
This is the first thing that most people would call a tunnel.
You could think of it as half a tunnel. If you walk into a
mountain and come out again the same way, you entered via an
adit.
- drift
A horizontal opening that runs along the vein.
Typically there are many ore chutes from stopes above,
and the drift will wander to follow the vein.
- crosscut
A horizontal opening that does not run along the vein.
Typically a shaft will lead to crosscuts at each level
that give access to drifts along the vein. Crosscuts
typically run straight as an arrow through worthless rock.
- shaft
A shaft can be vertical or inclined. Vertical shafts
allow more efficient hoisting and are typical of large
mines that followed a vein deep. Inclined shafts are
economical in the sense that they follow the vein and
stay close to it. Inclined shafts are also less
hazardous to mine explorers.
- chute
A "spout" built of wood used to load broken rock from
above into waiting mine cars. One of these means
you are below a stope or raise and there very well may
be a ladder next to it heading up.
- raise
A raise is like a shaft that starts undergound and
goes upwards. Typically a ladder next to an ore chute
along a drift goes up a raise and gives access to a
stope above.
- winze
A winze is like a shaft that starts undergound. They
are much less common than raises, but they are really
cool. Often the top of a winze has a good sized
station that once held (or still holds)
hoisting equipment, and enough room to transfer
material from hoist buckets to ore cars.
- stope
An excavation underground that actually removed
whatever it was they were after. These are typically
irregular in shape as they follow the ore whereever it goes.
If the vein is wide and/or the rock is poor, the challenge
in mining is to keep the rock supported while extracting
the material in the stope.
- level
If you follow a ladder down a shaft, you will arrive at
horizontal workings every 100 feet or so, and these are
called levels. The levels have a station near the shaft,
and are named by the distance down the shaft. For example
you might talk about a specimen as beeing from the 500 foot
level of the Bull Elk mine.
- station
Where each level meets a shaft is commonly a station with
benches, electrical distribution, telephone, mine bell
signal charts, and lots of cool stuff.
- pillar
A block of rock left behind to help support a stope.
These provide great opportunities to see what the ore
looked like. Pillar robbing is a deadly game that
involves seeing how much the pillars can be shaved back
before the whole stope collapses.
- square set stope
The most expensive mode of underground mining. As ore is
removed in a stope, it is replaced by a 10x10 foot lattice
of 12x12 timbers. This is fairly uncommon, but really
cool when you come across one in good condition. Just
remember that the ground was really bad or they wouldn't
have gone to all that trouble. Many times the sets are
backfilled with broken rock to help support the stope.
- hanging wall
Imagine yourself standing inside a stope that angles
down into the earth. The vein they extracted was
bounded by two surfaces. The one over your head is the
hanging wall.
- footwall
Continuing the thought above, the surface you are standing
on is the footwall. The same nomenclature is used of
faults by the way.
- manway
Any kind of passage with a ladder in it could be called a
manway. Shafts are divided into "compartments" and one of
these is very often a manway. Sometimes the manway of a
shaft is crowded with pipes and cables and such.
Feedback? Questions?
Drop me a line!
Uncle Tom's Old Mine Info / [email protected]