was a warm, fall day when we went to the Lackawanna Coal Mine in
Scranton, Pennsylvania. We were excited to be going into
slope mine. Coal had stopped being mined in
1966 and now the mine is an area tourist attraction. This
was an anthracite coal mine that had layers of
between the coal
beds. The tour guide told us that
the sandstone made a strong roof. They stopped mining
here because it cost a lot of money to pump the water out of the
mine all the time and they couldn’t pump it into the river
anymore. This is because there are toxic chemicals in mine
water and the Environmental Protection Agency of our government
would not allow it to be pumped into rivers anymore.
First we got into
the bright yellow mine car on the right. This was
used to take the men down the slope and into the mine. It had a
very low roof, even for us. You could not stand up in the car.
We had no idea what we would find below. The first thing
we saw was that it was cool down there and we were very glad
that we had worn jackets. Mine temperatures stay the same
most of the time--even when it's really hot outside.
One of the biggest threats in a coal mine is the
natural gasses that form below the surface. Coal mines need to
have very good
ventilation or the miners will die from
inhaling the gas. This mine is set up for tourists and someone
goes down into the mine a couple times a day to check the gas
levels. It made us feel very glad to hear that until our tour guide
said that the gas level was at its worst in the morning because
the blowers were turned off at night and gas accumulated in the
mine. It was 10 o’clock in the morning.
Mines like this one use wooden
beams, or timbers, to
hold up the walls and roof of the mine.
Wedges, which are
triangular pieces of wood, were used to make the beam fit
tightly against the ceiling. The picture on the left shows
the beam and wedge.
There is a passageway through the middle of the mine
that is called a gangway. They used this to get the coal out of
the mine, to support the land above it, and to be a firebreak.
A firebreak is an empty space that is used to help stop fire
from spreading to the whole mine.
In this mine, rooms or chambers opened off of this
gangway. Pillars of coal form these rooms and support the
roof. Each room opened off the gangway but it also opened into
other chambers so that a miner had different ways to escape if
something went wrong in the mine.
A mine is “played-out” when the rock or mineral that is
being mined has all been taken out, or it would cost too much
money to keep digging for it. Mine engineers and owners figure
out how much money they can expect to get for the rock or
mineral before it is even taken out of the mine. Then they
figure out how much money it costs to pay the miners and run the
machinery and equipment. The cost includes things we never
think of like electricity, insurance, and other things like
gasoline. The engineers figure out how many hours and days it
will take to get a certain
vein mined and then compare it to
what they will get when they sell it. For example, let’s say
that the mine is coming to the end of its coal. An engineer
knows that the company will get $100.00 for a ton of coal—which
is just an example and not a fact. He knows that two men will
have to work for two days to get that ton of coal out because it
is a hard place to get to, water has to be pumped out first, and
the miners have to crawl to get to it. Let’s say the two men
each get $50.00 a day. This equals $200.00 just to pay the men
to get the ton of coal out of the mine. It doesn’t include the
electricity, insurance, and other costs and still goes over the
$100.00 that the company would get for it. In this case, the
mine owner would decide not to do
it because it would
cost more to mine than he would get by selling it.
When the mine owner and engineer decide that it’s time
to stop mining, the
miners begin to chip away at the pillars of
coal that formed the chambers or rooms. Starting at the back of
the mine, they take the coal out of the pillars. This is called
“robbing the pillars.” Once you take the coal out of the
pillars, the roof begins to fall. This is why you do the back
first. If they started at the front, they would be trapped when
the roof fell.
Our tour guide told us that 70% of hillside mining is
done on the miner’s hands and knees or on their stomachs.
In the picture on the right, we see an example of this. We
saw chambers where we, as children, could not stand up. There
were life-size, make-believe miners set up to show the way coal
was mined. In some places, the ‘miners’ were lying down on their
stomachs or backs and chipping at the ceilings and walls. It
would have been a good thing to be small in coal mining!