Anyone here know about blasting person-height&width tunnels in hard
rock?

I have some contacts here (UK), but broadening the casting around for
information. Maybe bringing in North American perspective.
Especially noting how much I have gained here from previous ask about
mine haulage-shafts and skips.

New to me. If I'm pointed in the right direction and told the real
deal(s) to look out for, I can do a lot of my own reading.

Some of the rock here is "killas" - a heated "metamorphosed"
sedimentary rock which is quite brittle. Usually associated with
"wet" mines.
Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
cannot touch some when driven by a rock-drill which can go 1~1/2metres
in minutes with a simple chisel-edged carbide-tipped drill bit. Mines
in that can go a mile out under the sea and be dry.
As best I can explain from what I have seen; being a metallurgist and
welder.

There's something which would be very useful here making everything
possible, so it seems.

Something about electronically timed detonators which can serially
detonate "go off at the same time" charges a few microseconds apart,
which is apparently enough that at the surface only the effect of one
charge is felt.

So pointers on that would be appreciated.

Blasting mine tunnels is done radially here I gather from what I have
seen explained at mining museums - blast from the middle outwards,
sending the fractured rock towards the middle (heard of the central
hole being "reamed" - no charge in it obviously - provides the first
void to collapse the first ring of rock into).

Historically gelignite but noted that "ampho" is usually cheaper now.

Another reason for asking for a North American viewpoint is that folk
are much less restricted there - and therefore you get a lot of very
practically experienced folk. eg. when in Texas my host took me to
the range every morning with two holdalls full of hardware - learned a
lot quickly.
Everyone has to be very stern and restricted here trying to appease
the powers-that-be that everyone is very serious and narrow focussed -
no "plinking" or anything like that - and carries over into methods to
make lighter of rearranging rock.

Searching the Web on my own, I wouldn't know when I am "finding gold"
and when it's rubbish.

If you want to personal-message me, go to my website "weldsmith.co.uk"
and use the "Contact me" form and we can pick up on a private email
chat if you prefer that.

Thanks in advance,
Rich Smith

On 12/17/2023 11:56 AM, Richard Smith wrote:
> Anyone here know about blasting person-height&width tunnels in hard
> rock?
>
> I have some contacts here (UK), but broadening the casting around for
> information. Maybe bringing in North American perspective.
> Especially noting how much I have gained here from previous ask about
> mine haulage-shafts and skips.
>
> New to me. If I'm pointed in the right direction and told the real
> deal(s) to look out for, I can do a lot of my own reading.
>
> Some of the rock here is "killas" - a heated "metamorphosed"
> sedimentary rock which is quite brittle. Usually associated with
> "wet" mines.
> Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
> cannot touch some when driven by a rock-drill which can go 1~1/2metres
> in minutes with a simple chisel-edged carbide-tipped drill bit. Mines
> in that can go a mile out under the sea and be dry.
> As best I can explain from what I have seen; being a metallurgist and
> welder.
>
> There's something which would be very useful here making everything
> possible, so it seems.
>
> Something about electronically timed detonators which can serially
> detonate "go off at the same time" charges a few microseconds apart,
> which is apparently enough that at the surface only the effect of one
> charge is felt.
>
> So pointers on that would be appreciated.
>
> Blasting mine tunnels is done radially here I gather from what I have
> seen explained at mining museums - blast from the middle outwards,
> sending the fractured rock towards the middle (heard of the central
> hole being "reamed" - no charge in it obviously - provides the first
> void to collapse the first ring of rock into).
>
> Historically gelignite but noted that "ampho" is usually cheaper now.
>
> Another reason for asking for a North American viewpoint is that folk
> are much less restricted there - and therefore you get a lot of very
> practically experienced folk. eg. when in Texas my host took me to
> the range every morning with two holdalls full of hardware - learned a
> lot quickly.
> Everyone has to be very stern and restricted here trying to appease
> the powers-that-be that everyone is very serious and narrow focussed -
> no "plinking" or anything like that - and carries over into methods to
> make lighter of rearranging rock.
>
> Searching the Web on my own, I wouldn't know when I am "finding gold"
> and when it's rubbish.
>
> If you want to personal-message me, go to my website "weldsmith.co.uk"
> and use the "Contact me" form and we can pick up on a private email
> chat if you prefer that.
>
> Thanks in advance,
> Rich Smith

No. Not one bit. I suspect small shaped charges might be the ticket if
blasting were the only option, but the little bit of blasting I've been
around used "cruder" explosives due to cost. Things like bags or urea
dropped down a hole with diesel and blasting caps. Somewhere around my
dad's house is a VHS tape I recorded out in the desert from when Western
rock removed almost the entire south face of Aztec hill. I don't recall
how much urea they said they used any more, but it was a lot. Not much
of a show. Three little puffs of dust out the bore holes, a hint of
movement, and then 30-45 minutes waiting for the dust to clear even
though it was a windy day.

They'd spent weeks talking up their big blast in local stores and bars...

I might see if my dad still has that tape. It might be fun to digitize
and put on YouTube....

350LB of Urea & Diesel GOES POP!
--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

Bob La Londe <none@none.com99> writes:

> On 12/17/2023 11:56 AM, Richard Smith wrote:
>> Anyone here know about blasting person-height&width tunnels in hard
>> rock?
>>
>> I have some contacts here (UK), but broadening the casting around for
>> information. Maybe bringing in North American perspective.
>> Especially noting how much I have gained here from previous ask about
>> mine haulage-shafts and skips.
>>
>> New to me. If I'm pointed in the right direction and told the real
>> deal(s) to look out for, I can do a lot of my own reading.
>>
>> Some of the rock here is "killas" - a heated "metamorphosed"
>> sedimentary rock which is quite brittle. Usually associated with
>> "wet" mines.
>> Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
>> cannot touch some when driven by a rock-drill which can go 1~1/2metres
>> in minutes with a simple chisel-edged carbide-tipped drill bit. Mines
>> in that can go a mile out under the sea and be dry.
>> As best I can explain from what I have seen; being a metallurgist and
>> welder.
>>
>> There's something which would be very useful here making everything
>> possible, so it seems.
>>
>> Something about electronically timed detonators which can serially
>> detonate "go off at the same time" charges a few microseconds apart,
>> which is apparently enough that at the surface only the effect of one
>> charge is felt.
>>
>> So pointers on that would be appreciated.
>>
>> Blasting mine tunnels is done radially here I gather from what I have
>> seen explained at mining museums - blast from the middle outwards,
>> sending the fractured rock towards the middle (heard of the central
>> hole being "reamed" - no charge in it obviously - provides the first
>> void to collapse the first ring of rock into).
>>
>> Historically gelignite but noted that "ampho" is usually cheaper now.
>>
>> Another reason for asking for a North American viewpoint is that folk
>> are much less restricted there - and therefore you get a lot of very
>> practically experienced folk. eg. when in Texas my host took me to
>> the range every morning with two holdalls full of hardware - learned a
>> lot quickly.
>> Everyone has to be very stern and restricted here trying to appease
>> the powers-that-be that everyone is very serious and narrow focussed -
>> no "plinking" or anything like that - and carries over into methods to
>> make lighter of rearranging rock.
>>
>> Searching the Web on my own, I wouldn't know when I am "finding gold"
>> and when it's rubbish.
>>
>> If you want to personal-message me, go to my website "weldsmith.co.uk"
>> and use the "Contact me" form and we can pick up on a private email
>> chat if you prefer that.
>>
>> Thanks in advance,
>> Rich Smith
>
>
> No. Not one bit. I suspect small shaped charges might be the ticket
> if blasting were the only option, but the little bit of blasting I've
> been around used "cruder" explosives due to cost. Things like bags or
> urea dropped down a hole with diesel and blasting caps. Somewhere
> around my dad's house is a VHS tape I recorded out in the desert from
> when Western rock removed almost the entire south face of Aztec hill.
> I don't recall how much urea they said they used any more, but it was
> a lot. Not much of a show. Three little puffs of dust out the bore
> holes, a hint of movement, and then 30-45 minutes waiting for the dust
> to clear even though it was a windy day.
>
> They'd spent weeks talking up their big blast in local stores and bars...
>
> I might see if my dad still has that tape. It might be fun to
> digitize and put on YouTube....
>
> 350LB of Urea & Diesel GOES POP!
> --
> Bob La Londe
> CNC Molds N Stuff
>
>
> --
> This email has been checked for viruses by AVG antivirus software.
> www.avg.com

Sorry - that's "ANFO", as you point out.

"Little puffs of dust" - apparently (my local connections) that's
exactly what you should get.
Exasperated comment that many Company "buy our wonderful product"
videos have plumes of ejected material because it looks good - but is
technically wrong and misleading.

Urea - I was thinking ammonium nitrate?
Apparently mining companies using tonnes of the stuff do their own
mixing.
However there are the made-up "prills" - seen as pink "bits" - for
more modest users it seems.

Shaped charges - not in this application?
The pattern the holes are drilled is doing all the "focusing" to get
optimal result. Cylindrical holes metres long filled with blasting
agent.

The thrill about using the Holman rock-drill - the "Holman Silver 3
Airleg" - N.Am. = "jackleg"

which I didn't mention (?) because I could find no good photos and
didn't take a camera with me down the mine because didn't know I
would be in the granite section (dry - killas section is like being
in a shower at times) and having my first go with a rock-drill -
anyway I ran a hole the size of a stick of gelignite (about 35mm?)
1~1/2metres into the hard granite wall of one of the levels in
minutes -- that was promising with the ex-miner stepping-away after
about a minute, satisfied to leave me running the hole -- the
drilling being parallel in the horizontal and vertical planes to
the central "reference" hole

lead to this next thought - the purpose of hole-drilling which can now
be done is blasting. And there is hope of finding a lode to the side
of the existing workings. Clear so cannot disturb historical workings.

The folk here damn' well know about all this stuff, but looking to
other views. Other cultures of mining. Looking to learn.

I have seen videos of blasting "panels" of rock in quarries.
This was done in quarries near where I grew-up.
When I was ill off school at home during the day, you would hear the
siren going for a couple of minutes, then a "bang". From the
limestone area a few miles away...

As I mentioned, the overall pattern of this blasting here in mining is
radial, about the lengthwise centre of the level being extended (if I
understand rightly - mainly from Geevor Mine museum).

On Sun, 17 Dec 2023 20:08:02 +0000
Richard Smith <null@void.com> wrote:

<snip>
>The folk here damn' well know about all this stuff, but looking to
>other views. Other cultures of mining. Looking to learn.

There are old catalogs and books at Archive.com that might be of
interest. This search should get you started:

https://archive.org/search?query=subject:"mining+tools"

--
Leon Fisk
Grand Rapids MI

Leon Fisk <lfiskgr@gmail.invalid> writes:

> On Sun, 17 Dec 2023 20:08:02 +0000
> Richard Smith <null@void.com> wrote:
>
> <snip>
>>The folk here damn' well know about all this stuff, but looking to
>>other views. Other cultures of mining. Looking to learn.
>
> There are old catalogs and books at Archive.com that might be of
> interest. This search should get you started:
>
> https://archive.org/search?query=subject:"mining+tools"
>
> --
> Leon Fisk
> Grand Rapids MI

Looks interesting - will come back to this.

On 12/17/2023 2:08 PM, Richard Smith wrote:

>
> Sorry - that's "ANFO", as you point out.
>
> "Little puffs of dust" - apparently (my local connections) that's
> exactly what you should get.
> Exasperated comment that many Company "buy our wonderful product"
> videos have plumes of ejected material because it looks good - but is
> technically wrong and misleading.
>
> Urea - I was thinking ammonium nitrate?
> Apparently mining companies using tonnes of the stuff do their own
> mixing.
> However there are the made-up "prills" - seen as pink "bits" - for
> more modest users it seems.

Yup , ammonium nitrate as the oxidizer , fuel oil as the fuel . I had
a couple of years back in the late 70's working with some very good
engineers of various disciplines at Thiokol Chemical's Wasatch Division
.. A couple of things I learned about ANFO is that the AN will absorb
just exactly the right amount of FO to be perfectly oxygen balanced and
that you've got to hit it pretty hard to make it detonate .

>
> Shaped charges - not in this application?

Shaped charges are easy and very effective . Stick a funnel in the
end of a tube with the pointed end in the tube . Fill the tube with
explosive and initiate from the opposite end from the funnel . Crude and
there's a lot more science involved to get the exact results you want
but you just built a shaped charge . Probably not effective for the type
of tunneling you're doing .

> The pattern the holes are drilled is doing all the "focusing" to get
> optimal result. Cylindrical holes metres long filled with blasting
> agent.
>
> The thrill about using the Holman rock-drill - the "Holman Silver 3
> Airleg" - N.Am. = "jackleg"
>
> which I didn't mention (?) because I could find no good photos and
> didn't take a camera with me down the mine because didn't know I
> would be in the granite section (dry - killas section is like being
> in a shower at times) and having my first go with a rock-drill -
> anyway I ran a hole the size of a stick of gelignite (about 35mm?)
> 1~1/2metres into the hard granite wall of one of the levels in
> minutes -- that was promising with the ex-miner stepping-away after
> about a minute, satisfied to leave me running the hole -- the
> drilling being parallel in the horizontal and vertical planes to
> the central "reference" hole
>
> lead to this next thought - the purpose of hole-drilling which can now
> be done is blasting. And there is hope of finding a lode to the side
> of the existing workings. Clear so cannot disturb historical workings.
>
> The folk here damn' well know about all this stuff, but looking to
> other views. Other cultures of mining. Looking to learn.
>
> I have seen videos of blasting "panels" of rock in quarries.
> This was done in quarries near where I grew-up.
> When I was ill off school at home during the day, you would hear the
> siren going for a couple of minutes, then a "bang". From the
> limestone area a few miles away...
>
> As I mentioned, the overall pattern of this blasting here in mining is
> radial, about the lengthwise centre of the level being extended (if I
> understand rightly - mainly from Geevor Mine museum).
>

Happy blasting ! You mentioned at some point in this discussion
"small puffs" coming from the blasting holes . Actually those holes
should be packed with material to confine the blast . Anything being
ejected into open air is wasted energy that was not used for the primary
task of (in this case) shattering rock . (I also studied Dad's copy of
the DuPont Blaster's Handbook whenever I could sneak a peek.)
--
Snag
Men don't protect women because they're weak .
We protect them because they're important .

Further to original post:
I have looked on-line.
Going for the very specific search
"electronic timer blasting"
lead me to
"electronic detonator blasting"
with many relevant finds.
Seems is a big industry.
Hopefully by what I learn and by going for more very specific searches
I can find my way into this topic.

One example find is
https://www.epc-groupe.co.uk/products/
where they list many products for blasting.

Different "takes" on the matter are appreciated.

On 12/17/2023 1:08 PM, Richard Smith wrote:
> Bob La Londe <none@none.com99> writes:
>
>> On 12/17/2023 11:56 AM, Richard Smith wrote:
>>> Anyone here know about blasting person-height&width tunnels in hard
>>> rock?
>>>
>>> I have some contacts here (UK), but broadening the casting around for
>>> information. Maybe bringing in North American perspective.
>>> Especially noting how much I have gained here from previous ask about
>>> mine haulage-shafts and skips.
>>>
>>> New to me. If I'm pointed in the right direction and told the real
>>> deal(s) to look out for, I can do a lot of my own reading.
>>>
>>> Some of the rock here is "killas" - a heated "metamorphosed"
>>> sedimentary rock which is quite brittle. Usually associated with
>>> "wet" mines.
>>> Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
>>> cannot touch some when driven by a rock-drill which can go 1~1/2metres
>>> in minutes with a simple chisel-edged carbide-tipped drill bit. Mines
>>> in that can go a mile out under the sea and be dry.
>>> As best I can explain from what I have seen; being a metallurgist and
>>> welder.
>>>
>>> There's something which would be very useful here making everything
>>> possible, so it seems.
>>>
>>> Something about electronically timed detonators which can serially
>>> detonate "go off at the same time" charges a few microseconds apart,
>>> which is apparently enough that at the surface only the effect of one
>>> charge is felt.
>>>
>>> So pointers on that would be appreciated.
>>>
>>> Blasting mine tunnels is done radially here I gather from what I have
>>> seen explained at mining museums - blast from the middle outwards,
>>> sending the fractured rock towards the middle (heard of the central
>>> hole being "reamed" - no charge in it obviously - provides the first
>>> void to collapse the first ring of rock into).
>>>
>>> Historically gelignite but noted that "ampho" is usually cheaper now.
>>>
>>> Another reason for asking for a North American viewpoint is that folk
>>> are much less restricted there - and therefore you get a lot of very
>>> practically experienced folk. eg. when in Texas my host took me to
>>> the range every morning with two holdalls full of hardware - learned a
>>> lot quickly.
>>> Everyone has to be very stern and restricted here trying to appease
>>> the powers-that-be that everyone is very serious and narrow focussed -
>>> no "plinking" or anything like that - and carries over into methods to
>>> make lighter of rearranging rock.
>>>
>>> Searching the Web on my own, I wouldn't know when I am "finding gold"
>>> and when it's rubbish.
>>>
>>> If you want to personal-message me, go to my website "weldsmith.co.uk"
>>> and use the "Contact me" form and we can pick up on a private email
>>> chat if you prefer that.
>>>
>>> Thanks in advance,
>>> Rich Smith
>>
>>
>> No. Not one bit. I suspect small shaped charges might be the ticket
>> if blasting were the only option, but the little bit of blasting I've
>> been around used "cruder" explosives due to cost. Things like bags or
>> urea dropped down a hole with diesel and blasting caps. Somewhere
>> around my dad's house is a VHS tape I recorded out in the desert from
>> when Western rock removed almost the entire south face of Aztec hill.
>> I don't recall how much urea they said they used any more, but it was
>> a lot. Not much of a show. Three little puffs of dust out the bore
>> holes, a hint of movement, and then 30-45 minutes waiting for the dust
>> to clear even though it was a windy day.
>>
>> They'd spent weeks talking up their big blast in local stores and bars...
>>
>> I might see if my dad still has that tape. It might be fun to
>> digitize and put on YouTube....
>>
>> 350LB of Urea & Diesel GOES POP!
>> --
>> Bob La Londe
>> CNC Molds N Stuff
>>
>>
>> --
>> This email has been checked for viruses by AVG antivirus software.
>> www.avg.com
>
> Sorry - that's "ANFO", as you point out.
>
> "Little puffs of dust" - apparently (my local connections) that's
> exactly what you should get.
> Exasperated comment that many Company "buy our wonderful product"
> videos have plumes of ejected material because it looks good - but is
> technically wrong and misleading.
>
> Urea - I was thinking ammonium nitrate?
> Apparently mining companies using tonnes of the stuff do their own
> mixing.
> However there are the made-up "prills" - seen as pink "bits" - for
> more modest users it seems.
>
> Shaped charges - not in this application?
> The pattern the holes are drilled is doing all the "focusing" to get
> optimal result. Cylindrical holes metres long filled with blasting
> agent.
>
> The thrill about using the Holman rock-drill - the "Holman Silver 3
> Airleg" - N.Am. = "jackleg"
>
> which I didn't mention (?) because I could find no good photos and
> didn't take a camera with me down the mine because didn't know I
> would be in the granite section (dry - killas section is like being
> in a shower at times) and having my first go with a rock-drill -
> anyway I ran a hole the size of a stick of gelignite (about 35mm?)
> 1~1/2metres into the hard granite wall of one of the levels in
> minutes -- that was promising with the ex-miner stepping-away after
> about a minute, satisfied to leave me running the hole -- the
> drilling being parallel in the horizontal and vertical planes to
> the central "reference" hole
>
> lead to this next thought - the purpose of hole-drilling which can now
> be done is blasting. And there is hope of finding a lode to the side
> of the existing workings. Clear so cannot disturb historical workings.
>
> The folk here damn' well know about all this stuff, but looking to
> other views. Other cultures of mining. Looking to learn.
>
> I have seen videos of blasting "panels" of rock in quarries.
> This was done in quarries near where I grew-up.
> When I was ill off school at home during the day, you would hear the
> siren going for a couple of minutes, then a "bang". From the
> limestone area a few miles away...
>
> As I mentioned, the overall pattern of this blasting here in mining is
> radial, about the lengthwise centre of the level being extended (if I
> understand rightly - mainly from Geevor Mine museum).

I think urea is the same as ammonium nitrate. A lot of companies mix it
up on site because of transport regulations. In the states many
explosive components require little or no licensing to transport. They
would still need licensing for the blasting caps.

There is a watch on buying quantities of ammonium nitrate since the
Oklahoma Federal building truck bombing, but its still no more difficult
to transport than any other relatively safe farm chemical.

Here is an interesting aside. I can legally make a few explosives on my
own property for use on site for entertainment purposes only, but if I
put them in a strong container with a fuse or igniter they are a
destructive device which is required to be registered individually. I
can't legally make a pipe bomb, but I can legally make black powder (and
a few other things) as long as I don't transport it on public roads or
government regulated transport. (planes, trains, etc.) Now if I buy
that black powder at a store I can carry it around in my truck all day
long if I want to. LOL.

Being lazy, and wanting to take my Pennsylvania rifle to where the deer
are I buy my black powder (substitute) from a store.

--
Bob La Londe
CNC Molds N Stuff

On 12/17/2023 3:40 PM, Snag wrote:
> On 12/17/2023 2:08 PM, Richard Smith wrote:
>
>>
>> Sorry - that's "ANFO", as you point out.
>>
>> "Little puffs of dust" - apparently (my local connections) that's
>> exactly what you should get.
>> Exasperated comment that many Company "buy our wonderful product"
>> videos have plumes of ejected material because it looks good - but is
>> technically wrong and misleading.
>>
>> Urea - I was thinking ammonium nitrate?
>> Apparently mining companies using tonnes of the stuff do their own
>> mixing.
>> However there are the made-up "prills" - seen as pink "bits" - for
>> more modest users it seems.
>
>   Yup , ammonium nitrate as the oxidizer , fuel oil as the fuel . I had
> a couple of years back in the late 70's working with some very good
> engineers of various disciplines at Thiokol Chemical's Wasatch Division
> . A couple of things I learned about ANFO is that the AN will absorb
> just exactly the right amount of FO to be perfectly oxygen balanced and
> that you've got to hit it pretty hard to make it detonate .
>
>
>>
>> Shaped charges - not in this application?
>
>   Shaped charges are easy and very effective . Stick a funnel in the
> end of a tube with the pointed end in the tube . Fill the tube with
> explosive and initiate from the opposite end from the funnel . Crude and
> there's a lot more science involved to get the exact results you want
> but you just built a shaped charge . Probably not effective for the type
> of tunneling you're doing .
>
>
>> The pattern the holes are drilled is doing all the "focusing" to get
>> optimal result.  Cylindrical holes metres long filled with blasting
>> agent.
>>
>> The thrill about using the Holman rock-drill - the "Holman Silver 3
>> Airleg" - N.Am. = "jackleg"
>>
>>     which I didn't mention (?) because I could find no good photos and
>>     didn't take a camera with me down the mine because didn't know I
>>     would be in the granite section (dry - killas section is like being
>>     in a shower at times) and having my first go with a rock-drill -
>>     anyway I ran a hole the size of a stick of gelignite (about 35mm?)
>>     1~1/2metres into the hard granite wall of one of the levels in
>>     minutes -- that was promising with the ex-miner stepping-away after
>>     about a minute, satisfied to leave me running the hole -- the
>>     drilling being parallel in the horizontal and vertical planes to
>>     the central "reference" hole
>>
>> lead to this next thought - the purpose of hole-drilling which can now
>> be done is blasting.  And there is hope of finding a lode to the side
>> of the existing workings.  Clear so cannot disturb historical workings.
>>
>> The folk here damn' well know about all this stuff, but looking to
>> other views.  Other cultures of mining.  Looking to learn.
>>
>> I have seen videos of blasting "panels" of rock in quarries.
>> This was done in quarries near where I grew-up.
>> When I was ill off school at home during the day, you would hear the
>> siren going for a couple of minutes, then a "bang".  From the
>> limestone area a few miles away...
>>
>> As I mentioned, the overall pattern of this blasting here in mining is
>> radial, about the lengthwise centre of the level being extended (if I
>> understand rightly - mainly from Geevor Mine museum).
>>
>
>   Happy blasting ! You mentioned at some point in this discussion
> "small puffs" coming from the blasting holes . Actually those holes
> should be packed with material to confine the blast . Anything being
> ejected into open air is wasted energy that was not used for the primary
> task of (in this case) shattering rock . (I also studied Dad's copy of
> the DuPont Blaster's Handbook whenever I could sneak a peek.)

Going back before my time farmers used to keep dynamite for blasting out
trees. My mom told me her dad blasted out trees on their farm because
it would pop giant stumps right out of the ground and it left the earth
nice and soft for cultivation.

My dad tells a story about when he was a kid. I might have retold this
one here before. Near where he grew up he and his buddies used to play
and swim in French Creek. They had a spot they call their swimming
hole. It was the biggest pool on the creek, but there was a stump right
in the middle of it. The bunch of them griped about it for a while, and
one of the kids mentioned his dad had a case of dynamite in the garage.
It took them a while to work up their nerve, but they planned one day to
meet up at the creek, dig in under that stump, and blast it out. As my
dad and his buddy Tom where headed to the creek with tools to meet up
with the other guys the kid who had the dynamite came running back up
over that hill yelling, "Get down its about to blow!"

(My dad tells the story better.)

They all hit the ground and felt the earth shake from the explosion.
They saw the stump flying through the air back towards the main rode
where it landed in the driveway of the kid who brought the dynamite. It
just barely missed his dad's car as he was pulling in from the road.

They got to talk to him for a minute to ask how much he had used before
they heard his dad yelling for him.

He had debated about how much to use. He didn't want to go to light and
have to blast again. He knew after the first blast he'd have to clear
out because people might come to see what was going on if only to help a
neighbor drag out a stump in a field. He kept adding more, and before
he knew it he had packed the whole case under the stump.

My dad said after that they didn't have a swimming hole in the creek
anymore. They had a swimming pool, but they didn't see the kid with the
dynamite for the rest of the summer.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

Kids... We've all done it...

black powder...

I have fired some black-powder firers in the UK. Replicas.

I was surprised to see black powder listed in current stock with a
wholesaler when looking yesterday for timers, etc.
What??! :-)
Amazed, I looked with curiousity - and find it has a niche.
Masoned stone. Quarries for, I assume (?) Avoid shattering the rock
you want to extract in big "as it's been for hundreds of millions of
years" blocks.
Well, well, well - always a surprise.

"Richard Smith" wrote in message news:lyr0jk64l5.fsf@void.com...

Anyone here know about blasting person-height&width tunnels in hard
rock?
....
Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
cannot touch some when driven by a rock-drill which can go 1~1/2metres
in minutes with a simple chisel-edged carbide-tipped drill bit.

------------------
I can't help with this. My only rock drilling experience is on granite
boulders with a Makita HR3851 rotary hammer drill I was given because it had
broken. I use it with wedges and shims to trim inconveniently protruding
outcrops.

Your comments on your technohistorical wanderings are always interesting.

https://www.amazon.com/Ancient-Engineers-Astonishing-Wonders-Creators/dp/0345482875
The author was a rare example of a scientifically literate historian:
https://en.wikipedia.org/wiki/L._Sprague_de_Camp

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lyr0jk64l5.fsf@void.com...
>
> Anyone here know about blasting person-height&width tunnels in hard
> rock?
> ...
> Then there is hard granite. Very hard. A 4-carbide-teeth drill bit
> cannot touch some when driven by a rock-drill which can go 1~1/2metres
> in minutes with a simple chisel-edged carbide-tipped drill bit.
>
> ------------------
> I can't help with this. My only rock drilling experience is on granite
> boulders with a Makita HR3851 rotary hammer drill I was given because
> it had broken. I use it with wedges and shims to trim inconveniently
> protruding outcrops.
>
> Your comments on your technohistorical wanderings are always interesting.
>
> https://www.amazon.com/Ancient-Engineers-Astonishing-Wonders-Creators/dp/0345482875
> The author was a rare example of a scientifically literate historian:
> https://en.wikipedia.org/wiki/L._Sprague_de_Camp

I've seen breaking boulders by drilling a hole, putting in
semicircular taper wedges and driving a metal solid cylindrical wedge
down the middle (low friction?).

Seen chalcopyrite (sulfide copper ore) glistening in the fractured
section where it has been there hermetically sealed in the granite for
the 300million-ish years since it was deposited (not commercially
viable extraction, but there)

Thanks for the
Ancient-Engineers-Astonishing-Wonders-Creators
L._Sprague_de_Camp
hint - looks a good book to get.

I've just had a good week teaching welding (I said "No way!", they
said "Yes it will be fine", so I gave it a whirl and it worked).

So looking forward to finding out blasting as a part of mining over
the Christmas period. "Busperson's holiday" from what I have devoted
myself to (metallurgy and welding) over the decades.

Best wishes and season's greetings

On 18/12/2023 7:24 am, Bob La Londe wrote:
> On 12/17/2023 1:08 PM, Richard Smith wrote:
>> Bob La Londe <none@none.com99> writes:
>>
>>> On 12/17/2023 11:56 AM, Richard Smith wrote:
>>>> Anyone here know about blasting person-height&width tunnels in hard
>>>> rock?
>>>>
>>>> I have some contacts here (UK), but broadening the casting around for
>>>> information.  Maybe bringing in North American perspective.
>>>> Especially noting how much I have gained here from previous ask about
>>>> mine haulage-shafts and skips.
>>>>
>>>> New to me.  If I'm pointed in the right direction and told the real
>>>> deal(s) to look out for, I can do a lot of my own reading.
>>>>
>>>> Some of the rock here is "killas" - a heated "metamorphosed"
>>>> sedimentary rock which is quite brittle.  Usually associated with
>>>> "wet" mines.
>>>> Then there is hard granite.  Very hard.  A 4-carbide-teeth drill bit
>>>> cannot touch some when driven by a rock-drill which can go 1~1/2metres
>>>> in minutes with a simple chisel-edged carbide-tipped drill bit.  Mines
>>>> in that can go a mile out under the sea and be dry.
>>>> As best I can explain from what I have seen; being a metallurgist and
>>>> welder.
>>>>
>>>> There's something which would be very useful here making everything
>>>> possible, so it seems.
>>>>
>>>> Something about electronically timed detonators which can serially
>>>> detonate "go off at the same time" charges a few microseconds apart,
>>>> which is apparently enough that at the surface only the effect of one
>>>> charge is felt.
>>>>
>>>> So pointers on that would be appreciated.
>>>>
>>>> Blasting mine tunnels is done radially here I gather from what I have
>>>> seen explained at mining museums - blast from the middle outwards,
>>>> sending the fractured rock towards the middle (heard of the central
>>>> hole being "reamed" - no charge in it obviously - provides the first
>>>> void to collapse the first ring of rock into).
>>>>
>>>> Historically gelignite but noted that "ampho" is usually cheaper now.
>>>>
>>>> Another reason for asking for a North American viewpoint is that folk
>>>> are much less restricted there - and therefore you get a lot of very
>>>> practically experienced folk.  eg. when in Texas my host took me to
>>>> the range every morning with two holdalls full of hardware - learned a
>>>> lot quickly.
>>>> Everyone has to be very stern and restricted here trying to appease
>>>> the powers-that-be that everyone is very serious and narrow focussed -
>>>> no "plinking" or anything like that - and carries over into methods to
>>>> make lighter of rearranging rock.
>>>>
>>>> Searching the Web on my own, I wouldn't know when I am "finding gold"
>>>> and when it's rubbish.
>>>>
>>>> If you want to personal-message me, go to my website "weldsmith.co.uk"
>>>> and use the "Contact me" form and we can pick up on a private email
>>>> chat if you prefer that.
>>>>
>>>> Thanks in advance,
>>>> Rich Smith
>>>
>>>
>>> No.  Not one bit.  I suspect small shaped charges might be the ticket
>>> if blasting were the only option, but the little bit of blasting I've
>>> been around used "cruder" explosives due to cost.  Things like bags or
>>> urea dropped down a hole with diesel and blasting caps.  Somewhere
>>> around my dad's house is a VHS tape I recorded out in the desert from
>>> when Western rock removed almost the entire south face of Aztec hill.
>>> I don't recall how much urea they said they used any more, but it was
>>> a lot.  Not much of a show.  Three little puffs of dust out the bore
>>> holes, a hint of movement, and then 30-45 minutes waiting for the dust
>>> to clear even though it was a windy day.
>>>
>>> They'd spent weeks talking up their big blast in local stores and
>>> bars...
>>>
>>> I might see if my dad still has that tape.  It might be fun to
>>> digitize and put on YouTube....
>>>
>>> 350LB of Urea & Diesel GOES POP!
>>> --
>>> Bob La Londe
>>> CNC Molds N Stuff
>>>
>>>
>>> --
>>> This email has been checked for viruses by AVG antivirus software.
>>> www.avg.com
>>
>> Sorry - that's "ANFO", as you point out.
>>
>> "Little puffs of dust" - apparently (my local connections) that's
>> exactly what you should get.
>> Exasperated comment that many Company "buy our wonderful product"
>> videos have plumes of ejected material because it looks good - but is
>> technically wrong and misleading.
>>
>> Urea - I was thinking ammonium nitrate?
>> Apparently mining companies using tonnes of the stuff do their own
>> mixing.
>> However there are the made-up "prills" - seen as pink "bits" - for
>> more modest users it seems.
>>
>> Shaped charges - not in this application?
>> The pattern the holes are drilled is doing all the "focusing" to get
>> optimal result.  Cylindrical holes metres long filled with blasting
>> agent.
>>
>> The thrill about using the Holman rock-drill - the "Holman Silver 3
>> Airleg" - N.Am. = "jackleg"
>>
>>     which I didn't mention (?) because I could find no good photos and
>>     didn't take a camera with me down the mine because didn't know I
>>     would be in the granite section (dry - killas section is like being
>>     in a shower at times) and having my first go with a rock-drill -
>>     anyway I ran a hole the size of a stick of gelignite (about 35mm?)
>>     1~1/2metres into the hard granite wall of one of the levels in
>>     minutes -- that was promising with the ex-miner stepping-away after
>>     about a minute, satisfied to leave me running the hole -- the
>>     drilling being parallel in the horizontal and vertical planes to
>>     the central "reference" hole
>>
>> lead to this next thought - the purpose of hole-drilling which can now
>> be done is blasting.  And there is hope of finding a lode to the side
>> of the existing workings.  Clear so cannot disturb historical workings.
>>
>> The folk here damn' well know about all this stuff, but looking to
>> other views.  Other cultures of mining.  Looking to learn.
>>
>> I have seen videos of blasting "panels" of rock in quarries.
>> This was done in quarries near where I grew-up.
>> When I was ill off school at home during the day, you would hear the
>> siren going for a couple of minutes, then a "bang".  From the
>> limestone area a few miles away...
>>
>> As I mentioned, the overall pattern of this blasting here in mining is
>> radial, about the lengthwise centre of the level being extended (if I
>> understand rightly - mainly from Geevor Mine museum).
>
> I think urea is the same as ammonium nitrate.  A lot of companies mix it
> up on site because of transport regulations.  In the states many
> explosive components require little or no licensing to transport.  They
> would still need licensing for the blasting caps.
>
> There is a watch on buying quantities of ammonium nitrate since the
> Oklahoma Federal building truck bombing, but its still no more difficult
> to transport than any other relatively safe farm chemical.
>
> Here is an interesting aside.  I can legally make a few explosives on my
> own property for use on site for entertainment purposes only, but if I
> put them in a strong container with a fuse or igniter they are a
> destructive device which is required to be registered individually.  I
> can't legally make a pipe bomb, but I can legally make black powder (and
> a few other things) as long as I don't transport it on public roads or
> government regulated transport.  (planes, trains, etc.)   Now if I buy
> that black powder at a store I can carry it around in my truck all day
> long if I want to.  LOL.
>
> Being lazy, and wanting to take my Pennsylvania rifle to where the deer
> are I buy my black powder (substitute) from a store.
>
Urea /= Ammonium Nitrate. See Wikipedia: AN is mixed with diesel to make
an explosive; urea is inert of itself, & must be reacted with nitric
acid to give urea nitrate, which is explosive (needing no oil).

On Tue, 19 Dec 2023 07:55:41 +0000
Richard Smith <null@void.com> wrote:

<snip>
>So looking forward to finding out blasting as a part of mining over
>the Christmas period. "Busperson's holiday" from what I have devoted
>myself to (metallurgy and welding) over the decades.

Suspect you may find the book "The Anarchist Cookbook" of interest:

https://annas-archive.org/search?q=anarchist+cookbook+powell

several copies, different formats there. This maybe a decent pdf🤷

https://annas-archive.org/md5/e369ed0f88454868628e6395da158a30

Has quite a bit of info on explosives...

--
Leon Fisk
Grand Rapids MI

On 12/19/2023 7:05 AM, Leon Fisk wrote:
> On Tue, 19 Dec 2023 07:55:41 +0000
> Richard Smith <null@void.com> wrote:
>
> <snip>
>> So looking forward to finding out blasting as a part of mining over
>> the Christmas period. "Busperson's holiday" from what I have devoted
>> myself to (metallurgy and welding) over the decades.
>
> Suspect you may find the book "The Anarchist Cookbook" of interest:
>
> https://annas-archive.org/search?q=anarchist+cookbook+powell
>
> several copies, different formats there. This maybe a decent pdf🤷
>
> https://annas-archive.org/md5/e369ed0f88454868628e6395da158a30
>
> Has quite a bit of info on explosives...
>

I've often wondered if there is a legit copy of the anarachist cookbook
that isn't explicitly dangerous to the reader. The reason I say this is
I have never held a print copy. However many years ago with a different
frame of mind we once logged onto a server in France through a relay
that appeared to be a black market trading board. Lots of early scripts
and hacking tools, trading stolen credit card and bank account numbers.
That sort of thing. One thing in the archives was a text file claiming
to be the Anarchist Cookbook. We read many recipes, and most appeared
to be more annoying than anything else. A few were downright dangerous
to follow. I don't recall reading anything that was really good nuts
and bolts of destructive mixture/devices.

--
Bob La Londe
CNC Molds N Stuff

--
This email has been checked for viruses by AVG antivirus software.
www.avg.com

On Tue, 19 Dec 2023 13:04:40 -0700
Bob La Londe <none@none.com99> wrote:

<snip>
>I've often wondered if there is a legit copy of the anarachist cookbook
>that isn't explicitly dangerous to the reader. The reason I say this is
>I have never held a print copy. However many years ago with a different
>frame of mind we once logged onto a server in France through a relay
>that appeared to be a black market trading board. Lots of early scripts
>and hacking tools, trading stolen credit card and bank account numbers.
>That sort of thing. One thing in the archives was a text file claiming
>to be the Anarchist Cookbook. We read many recipes, and most appeared
>to be more annoying than anything else. A few were downright dangerous
>to follow. I don't recall reading anything that was really good nuts
>and bolts of destructive mixture/devices.

The original (Powell) was from 1971. Amazon reviewers (1 star) don't
think much of it... Thought it might give Richard a few grins or
possibly some ideas to search for better info😉

I see Amazon has several "More items to explore" that might treat
explosives in a better manner:

https://www.amazon.com/Anarchist-Cookbook-William-Powell/dp/1607966123/

--
Leon Fisk
Grand Rapids MI

>>...
>
> The original (Powell) was from 1971. Amazon reviewers (1 star) don't
> think much of it... Thought it might give Richard a few grins or
> possibly some ideas to search for better info
>
> ...

:-)

David Brooks <daveb@iinet.net.au> writes:

> On 18/12/2023 7:24 am, Bob La Londe wrote:
>> On 12/17/2023 1:08 PM, Richard Smith wrote:
>>> Bob La Londe <none@none.com99> writes:
>>>
>>>> On 12/17/2023 11:56 AM, Richard Smith wrote:
>>>>> Anyone here know about blasting person-height&width tunnels in hard
>>>>> rock?
>>>>>
>>>>> I have some contacts here (UK), but broadening the casting around for
>>>>> information.  Maybe bringing in North American perspective.
>>>>> Especially noting how much I have gained here from previous ask about
>>>>> mine haulage-shafts and skips.
>>>>>
>>>>> New to me.  If I'm pointed in the right direction and told the real
>>>>> deal(s) to look out for, I can do a lot of my own reading.
>>>>>
>>>>> Some of the rock here is "killas" - a heated "metamorphosed"
>>>>> sedimentary rock which is quite brittle.  Usually associated with
>>>>> "wet" mines.
>>>>> Then there is hard granite.  Very hard.  A 4-carbide-teeth drill bit
>>>>> cannot touch some when driven by a rock-drill which can go 1~1/2metres
>>>>> in minutes with a simple chisel-edged carbide-tipped drill bit.  Mines
>>>>> in that can go a mile out under the sea and be dry.
>>>>> As best I can explain from what I have seen; being a metallurgist and
>>>>> welder.
>>>>>
>>>>> There's something which would be very useful here making everything
>>>>> possible, so it seems.
>>>>>
>>>>> Something about electronically timed detonators which can serially
>>>>> detonate "go off at the same time" charges a few microseconds apart,
>>>>> which is apparently enough that at the surface only the effect of one
>>>>> charge is felt.
>>>>>
>>>>> So pointers on that would be appreciated.
>>>>>
>>>>> Blasting mine tunnels is done radially here I gather from what I have
>>>>> seen explained at mining museums - blast from the middle outwards,
>>>>> sending the fractured rock towards the middle (heard of the central
>>>>> hole being "reamed" - no charge in it obviously - provides the first
>>>>> void to collapse the first ring of rock into).
>>>>>
>>>>> Historically gelignite but noted that "ampho" is usually cheaper now.
>>>>>
>>>>> Another reason for asking for a North American viewpoint is that folk
>>>>> are much less restricted there - and therefore you get a lot of very
> ...
> trucks to be involved in an accident, & the whole lot goes bang. See
> https://www.abc.net.au/news/2022-11-03/truck-explosion-wa-goldfields-mining-blasting-/101609164
>
> ...

Job done well! :-)

David Brooks <daveb@iinet.net.au> writes:

>
> The mines mix AN & fuel oil in what's basically a truck-cement mixer,
> & pump it straight down the holes. The holes are wired together, with
> a sub-second delay between each, so you get a ripple effect, rather
> than one big bang.

With houses only a few 10's of metres overhead, might be looking for a
more sophisticated timing sequence than that.

Perth - sounds like the place to be a miner.
One tin mine is going to reopen here in Cornwall, UK.
Is South Crofty.
Being pumped. Over a year to go before down to the sump and can
tunnel deeper going for tin down there.

"Richard Smith" wrote in message news:lybkaoe9k3.fsf@void.com...

Further to original post:
I have looked on-line.
Going for the very specific search
"electronic timer blasting"
lead me to
"electronic detonator blasting"
with many relevant finds.
Seems is a big industry.
Hopefully by what I learn and by going for more very specific searches
I can find my way into this topic.

One example find is
https://www.epc-groupe.co.uk/products/
where they list many products for blasting.

Different "takes" on the matter are appreciated.

-----------------------------------------
https://miningandblasting.files.wordpress.com/2009/09/rock-excavation-handbook-tunneling.pdf
"Large cut holes are normally drilled by reaming. First, a smaller, for
example, 45mm diameter hole is drilled then
reamed to the final size using a pilot adapter and a reaming bit."

"Big, uncharged cut holes (76 - 127mm dia.) [3-5"] provide an opening for
the blasted, expanding
rock from the surrounding cut holes."

"Richard Smith" wrote in message news:lybkaoe9k3.fsf@void.com...

https://www.epc-groupe.co.uk/products/
where they list many products for blasting.
------------------------------

This shows the speed of non-electric blasting cord:
https://www.youtube.com/watch?v=i6k26SJFyB8

On 12/20/2023 9:19 AM, Jim Wilkins wrote:
> "Richard Smith"  wrote in message news:lybkaoe9k3.fsf@void.com...
> https://www.epc-groupe.co.uk/products/
> where they list many products for blasting.
> ------------------------------
>
> This shows the speed of non-electric blasting cord:
> https://www.youtube.com/watch?v=i6k26SJFyB8

IIRC primacord detonation head propagates at about 2000 meters/second .
I only got to play with it once or twice but it sure was fun !
--
Snag
Si Vis Pacem Para Bellum

"Snag" wrote in message news:ulvo3u$no9l$1@dont-email.me...

On 12/20/2023 9:19 AM, Jim Wilkins wrote:
> "Richard Smith" wrote in message news:lybkaoe9k3.fsf@void.com...
> https://www.epc-groupe.co.uk/products/
> where they list many products for blasting.
> ------------------------------
>
> This shows the speed of non-electric blasting cord:
> https://www.youtube.com/watch?v=i6k26SJFyB8

IIRC primacord detonation head propagates at about 2000 meters/second .
I only got to play with it once or twice but it sure was fun !
--
Snag
Si Vis Pacem Para Bellum

----------------------
The bridge main span was 170' long, the ends 160'.

I watched some blasting near my house. The operator said the cord contained
silver fulminate and he fired it with a shotgun primer.

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lybkaoe9k3.fsf@void.com...
>
> Further to original post:
> I have looked on-line.
> Going for the very specific search
> "electronic timer blasting"
> lead me to
> "electronic detonator blasting"
> with many relevant finds.
> Seems is a big industry.
> Hopefully by what I learn and by going for more very specific searches
> I can find my way into this topic.
>
> One example find is
> https://www.epc-groupe.co.uk/products/
> where they list many products for blasting.
>
> Different "takes" on the matter are appreciated.
>
> -----------------------------------------
> https://miningandblasting.files.wordpress.com/2009/09/rock-excavation-handbook-tunneling.pdf
> "Large cut holes are normally drilled by reaming. First, a smaller,
> for example, 45mm diameter hole is drilled then
> reamed to the final size using a pilot adapter and a reaming bit."
>
> "Big, uncharged cut holes (76 - 127mm dia.) [3-5"] provide an opening
> for the blasted, expanding
> rock from the surrounding cut holes."

Thanks. That's the sort of thing I was looking for.