What date did shotholes for mining start?

graham

graham

New member
Are you interested in shotholes used with blasting powder or with lime? The date that blasting powder was first used in this country is known quite well. Ecton copper mines in mid 17th century, can't remember exact date without looking it up.
 
whitelackington

whitelackington

New member
graham said:
Are you interested in shotholes used with blasting powder or with lime? The date that blasting powder was first used in this country is known quite well. Ecton copper mines in mid 17th century, can't remember exact date without looking it up.
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Thanx Graham, I was, of course meaning in Mendip Lead Mines :doubt:
 
shotlighter

shotlighter

Active member
whitelackington said:
graham said:
Are you interested in shotholes used with blasting powder or with lime? The date that blasting powder was first used in this country is known quite well. Ecton copper mines in mid 17th century, can't remember exact date without looking it up.
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Thanx Graham, I was, of course meaning in Mendip Lead Mines :doubt:
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Ecton is a very moot point. The date Hoosen quotes is 1673 (ish I'd have to go upstairs & look) but if you actually read him, he does not specifically mention black powder. The (supposed) large dia shotholes could just as easily be lime blasting holes, as they are about 2" in dia - a bugger to drill by hand, when you could easily use 3/4" holes for powder. The reason often quoted is that powder was crap then, so they need large dia holes. As my friend Mr Kirkham says "rubbish! they'd just spent years using it to fight the civil war", they were probably awash with good quality powder.
I've taken samples from 18cent. shotholes in the immediate vicinity, control samples from the wall & samples from the early shot holes. I've had these analyzed by SEM (twice on 2 different machines) & the 17 cent holes show no trace of powder residue. Ongoing project - watch out for future article in PDMHS journal.
 
graham

graham

New member
shotlighter said:
whitelackington said:
graham said:
Are you interested in shotholes used with blasting powder or with lime? The date that blasting powder was first used in this country is known quite well. Ecton copper mines in mid 17th century, can't remember exact date without looking it up.
Click to expand...
Thanx Graham, I was, of course meaning in Mendip Lead Mines :doubt:
Click to expand...
Ecton is a very moot point. The date Hoosen quotes is 1673 (ish I'd have to go upstairs & look) but if you actually read him, he does not specifically mention black powder. The (supposed) large dia shotholes could just as easily be lime blasting holes, as they are about 2" in dia - a bugger to drill by hand, when you could easily use 3/4" holes for powder. The reason often quoted is that powder was crap then, so they need large dia holes. As my friend Mr Kirkham says "rubbish! they'd just spent years using it to fight the civil war", they were probably awash with good quality powder.
I've taken samples from 18cent. shotholes in the immediate vicinity, control samples from the wall & samples from the early shot holes. I've had these analyzed by SEM (twice on 2 different machines) & the 17 cent holes show no trace of powder residue. Ongoing project - watch out for future article in PDMHS journal.
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Thanks for that, most interesting. We know, of course, that powder had been used in Europe before that date & as you say they should have had plenty of powder available to them, so why use lime?

Perhaps they only had a 2" drill?  :confused:
 
Les W

Les W

Active member
whitelackington said:
Once again sorry for being so unknowledgeable
but how does the lime powder work, does it just expand? :-\
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Google is your friend

http://www.mowcop.info/htm/stonequarries.htm

Near the bottom of the page.  (y)
 
M

martinr

Active member
Les W said:
whitelackington said:
Once again sorry for being so unknowledgeable
but how does the lime powder work, does it just expand? :-\
Click to expand...

Google is your friend

http://www.mowcop.info/htm/stonequarries.htm

Near the bottom of the page.  (y)
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For the benefit of WL: "Lime Blasting, lime is tamped into holes drilled in the rock, moistened with water and left over night. During which time the lime swells and so splits the rock. This method leaves quite large half holes 2-3" diameter and maybe 2ft long, .... Apparently the rock could be heard groaning & creaking during the night before finally splitting! "

 
Brains

Brains

Well-known member
All to do with the volume change from quick lime (CaO) to slaked lime (Ca(OH2)), still in use today for disrupting concrete etc where quicker acting substances cant be used, and not referred to as explosive as that is far to emotive and not technically correct either...
 
D

Dep

Guest
graham said:
...
Thanks for that, most interesting. We know, of course, that powder had been used in Europe before that date & as you say they should have had plenty of powder available to them, so why use lime?
...
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There was no shortage of gunpowder - we were an emerging naval super-power!

But that does not follow that powder would be available for small private companies - production was in the hands of the military - strictly for their use.

Also a similar reason for iron production moving away from the southeast back then - the remaining  timber (required for furnaces) was earmarked for ship-building.
 
shotlighter

shotlighter

Active member
Just to clarify, my point wasn't that they defiantly used powder in the large shot holes. Rather, that given the available knowledge at the time, they should have known that such big holes were unnecessary.
Took me a while to be persuaded of this, but it's probabley the case. Also I was not suggesting that powder was readily available (at a cost economical to mining enterprises) at the time - mearly that the knowledge of its use would be.
Lime of course would be plentiful & cheap, as a byproduct of the mining operation.
BTW glad you liked my stuff on lime use at Mow Cop :)
 
graham

graham

New member
Shotlighter, have you read this?

Stanton,W.I., 1983. Shotholes containing lime in a Mendip lead mine. UBSS Proceedings, 16(3) , pp 185-189.
Abstract: Shotholes in an 18th century lead mine were tamped with a mixture of lime and grit, possibly to keep the gunpowder charge dry by absorbing moisture. Lime-blasting was not used at this site.
 
shotlighter

shotlighter

Active member
graham said:
Shotlighter, have you read this?

Stanton,W.I., 1983. Shotholes containing lime in a Mendip lead mine. UBSS Proceedings, 16(3) , pp 185-189.
Abstract: Shotholes in an 18th century lead mine were tamped with a mixture of lime and grit, possibly to keep the gunpowder charge dry by absorbing moisture. Lime-blasting was not used at this site.
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No - but I'd like to!
 
graham

graham

New member
shotlighter said:
graham said:
Shotlighter, have you read this?

Stanton,W.I., 1983. Shotholes containing lime in a Mendip lead mine. UBSS Proceedings, 16(3) , pp 185-189.
Abstract: Shotholes in an 18th century lead mine were tamped with a mixture of lime and grit, possibly to keep the gunpowder charge dry by absorbing moisture. Lime-blasting was not used at this site.
Click to expand...
No - but I'd like to!
Click to expand...

I think we exchange with the PDMHS so you should find a copy in their library.
 
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