Post by AJrWennerGren on Jul 21, 2004 4:23:36 GMT -5
Richest & Deepest Gold Mines In The World ~
Gold mining and a unique relic ~
imgtu.swift.publicus.com/apps/pbcsi.dll/bilde?Site=TU&Date=20020622&Category=TODAYSFEATURE&ArtNo=106220007&Ref=AR&MaxW=580&title=1
This is the head frame at the mighty Empire Mine,
as it appeared in 1963.
The structure was blasted into eternity in 1969
when the owners said liability concerns were
too great to allow the wooden tower to remain.
For more than 90 years, between 1850 and
the United States entry into World War II,
the rich quartz mines of Western Nevada County
shipped an annual average of $8 million
in gold bullion to the San Francisco mint.
The Empire, Pennsylvania, Champion, North Star,
Golden Center and Idaho-Maryland,
among others, were the richest and
deepest gold mines in the world.
In Grass Valley, the North Star's central shaft
descended vertically 3,000 feet into the earth.
Incline shaft extensions and other passages
reached a depth of 10,500 feet from
the surface.
Hard-rock gold mining began here and experienced
far-reaching innovations, allowing years of
sustained and profitable production.
In 1942, by order of the federal government,
all gold mining was curtailed for the duration
of WWII as being "nonessential" to
the war effort.
Many of the miners went into military service,
some took employment in San Francisco Bay Area
shipyards, and still others worked at mining
metals vital to the war effort
in other locales.
Peace returned in 1945, and some of the mines
reopened anticipating a return
their pre-war output.
However, the cost to rehabilitate the mines,
coupled with inflated costs of production -
especially wages and new machinery -
rapidly approached and then exceeded
the value of gold produced, leaving
no profit or reinvestment capital.
In 1934, the federal government had fixed
the price of monetary gold (bullion)
at $35 per troy ounce and became the
only legal purchaser.
The mines were forced to sell only to
the U.S. mint, thereby binding them to
an artificially static price.
There were no restrictions on specimen gold
and nuggets for jewelry.
In 1956, an era came to a close when the
mighty Empire, the area's largest mine
and greatest producer, "pulled the pumps"
and stopped pumping ground water, which
allowed some 300-plus miles of underground
workings to flood.
Within two years, all machinery, tools
and equipment from the Empire, Pennsylvania
and other mines had been or was in
the process of being auctioned.
Today, except at the Empire, which has
become the Empire Mine State Historic Park,
all that remains is a foundation or two
and an occasional corrugated building to
mark the location of the gold mines that
were once the economic base of Nevada County.
Records show that more than half of all gold
produced in California came out of the ground
in this county.
An interesting experiment in gold mining
technology took place at
the big-producing Idaho-Maryland mine
in Grass Valley in 1935-36.
At a location on the mine property close
to Brunswick Road, the company's engineer
J.B. Newsom bored an experimental vertical
shaft 5 feet in diameter some 1,125 feet
into the earth through solid rock.
The traditional method to sink vertical or
incline shafts called for drilling, blasting
and then "mucking out" the loose rock.
Timbering followed to provide support for pipes,
power cables and other necessary equipment.
Timbering was expensive and required constant
and costly maintenance.
The vertical bore required no maintenance and
the necessary cables could be bolted to
the shaft walls.
Also, steel cage guides for underground transport
to and from the surface were easier to attach
to the smooth surface of the shaft than to
an uneven one caused by blasting.
The experimental shaft passed near the 500,
750 and 1,100-foot working levels of
the original Idaho-Maryland workings.
Newsom designed and built special equipment
for the drilling experiment.
A rotating, vertical core barrel drill and
a core puller both drilled and removed
sections of rock which were usually 7 feet
in length, weighing approximately 11 tons each.
According to records kept by Errol MacBoyle,
the mine's general manager, the greatest
footage drilled during the experiment
was 21 feet through solid rock in three days.
Evidently, the experiment did not produce
the expected results and the shaft
was never utilized.
Two of the shaft core sections were saved
and placed locally on public display.
One is at the Nevada County Fairgrounds;
the other is in Calanan Park in
Nevada City.
History often repeat itself ~
www.ivarkreuger.com/photos_emgold.htm
ivarkreuger.proboards32.com/index.cgi?board=Emgold
Gold mining and a unique relic ~
imgtu.swift.publicus.com/apps/pbcsi.dll/bilde?Site=TU&Date=20020622&Category=TODAYSFEATURE&ArtNo=106220007&Ref=AR&MaxW=580&title=1
This is the head frame at the mighty Empire Mine,
as it appeared in 1963.
The structure was blasted into eternity in 1969
when the owners said liability concerns were
too great to allow the wooden tower to remain.
For more than 90 years, between 1850 and
the United States entry into World War II,
the rich quartz mines of Western Nevada County
shipped an annual average of $8 million
in gold bullion to the San Francisco mint.
The Empire, Pennsylvania, Champion, North Star,
Golden Center and Idaho-Maryland,
among others, were the richest and
deepest gold mines in the world.
In Grass Valley, the North Star's central shaft
descended vertically 3,000 feet into the earth.
Incline shaft extensions and other passages
reached a depth of 10,500 feet from
the surface.
Hard-rock gold mining began here and experienced
far-reaching innovations, allowing years of
sustained and profitable production.
In 1942, by order of the federal government,
all gold mining was curtailed for the duration
of WWII as being "nonessential" to
the war effort.
Many of the miners went into military service,
some took employment in San Francisco Bay Area
shipyards, and still others worked at mining
metals vital to the war effort
in other locales.
Peace returned in 1945, and some of the mines
reopened anticipating a return
their pre-war output.
However, the cost to rehabilitate the mines,
coupled with inflated costs of production -
especially wages and new machinery -
rapidly approached and then exceeded
the value of gold produced, leaving
no profit or reinvestment capital.
In 1934, the federal government had fixed
the price of monetary gold (bullion)
at $35 per troy ounce and became the
only legal purchaser.
The mines were forced to sell only to
the U.S. mint, thereby binding them to
an artificially static price.
There were no restrictions on specimen gold
and nuggets for jewelry.
In 1956, an era came to a close when the
mighty Empire, the area's largest mine
and greatest producer, "pulled the pumps"
and stopped pumping ground water, which
allowed some 300-plus miles of underground
workings to flood.
Within two years, all machinery, tools
and equipment from the Empire, Pennsylvania
and other mines had been or was in
the process of being auctioned.
Today, except at the Empire, which has
become the Empire Mine State Historic Park,
all that remains is a foundation or two
and an occasional corrugated building to
mark the location of the gold mines that
were once the economic base of Nevada County.
Records show that more than half of all gold
produced in California came out of the ground
in this county.
An interesting experiment in gold mining
technology took place at
the big-producing Idaho-Maryland mine
in Grass Valley in 1935-36.
At a location on the mine property close
to Brunswick Road, the company's engineer
J.B. Newsom bored an experimental vertical
shaft 5 feet in diameter some 1,125 feet
into the earth through solid rock.
The traditional method to sink vertical or
incline shafts called for drilling, blasting
and then "mucking out" the loose rock.
Timbering followed to provide support for pipes,
power cables and other necessary equipment.
Timbering was expensive and required constant
and costly maintenance.
The vertical bore required no maintenance and
the necessary cables could be bolted to
the shaft walls.
Also, steel cage guides for underground transport
to and from the surface were easier to attach
to the smooth surface of the shaft than to
an uneven one caused by blasting.
The experimental shaft passed near the 500,
750 and 1,100-foot working levels of
the original Idaho-Maryland workings.
Newsom designed and built special equipment
for the drilling experiment.
A rotating, vertical core barrel drill and
a core puller both drilled and removed
sections of rock which were usually 7 feet
in length, weighing approximately 11 tons each.
According to records kept by Errol MacBoyle,
the mine's general manager, the greatest
footage drilled during the experiment
was 21 feet through solid rock in three days.
Evidently, the experiment did not produce
the expected results and the shaft
was never utilized.
Two of the shaft core sections were saved
and placed locally on public display.
One is at the Nevada County Fairgrounds;
the other is in Calanan Park in
Nevada City.
History often repeat itself ~
www.ivarkreuger.com/photos_emgold.htm
ivarkreuger.proboards32.com/index.cgi?board=Emgold