"DanG" wrote in message news:oxMTc.5863$vj.2393@okepread03...
According to my good mining friend out of Kalispell, Montana, a
single jack is one man swinging a hammer with one hand. A double
jack required 2 hands on the hammer and another man to hold the
drill.

I would like to know the etymology of jack in this one.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"SteveB" wrote in message
news:XHLTc.35748$Lj.29979@fed1read03...

"Harry K" wrote


Naw, naw. When you're using a sledge you don't worry about
hitting
your hand. Your -helper- might worry but who cares.

Harry K

Here in Nevada, when they have town celebrations in the old
mining areas,
they have a single jacking contest. This was when a two man
team would take
a star bit and a sledge, and drill a hole for dynamite. The
method was used
before the invention of pneumatic drillers, and by poorboy
operators who
couldn't afford the big drills.

Needless to say, it took practice for two men to do this all day
long. In
the competitions, one holds the drill, the other strikes it.
Then the drill
holder turns the bit a slight bit, and the other strikes it
again. All
seamless and nonstop. They do this for a predetermined length
of time, and
then the depth of the holes are measured. The winning team
usually gets a
small trophy and more beer.

Then they have mucking contests where they see how much blasted
rock and
debris a man can load in a minecar in 60 seconds. Makes one
appreciate the
strides in technology and machinery.

Steve



Yep, single jack = one man
double jack = 2 men

Double used a much heavier sledge than did single.

Having used single jack to break rocks in concrete (when my carbide
bits won't go through) using single jack, I for sure wouldn't want to
try earning my living that way.

Harry K