60/40 Solder.....

[pwdrive]

Or how the tin fits in.

This is the only known footage as far as I know of a raise round being drilled and blasted in Cornwall, the footage appears to be made for camera as it were so as to show the procedure of a now defunct art down here, 1st one is drilling, 2nd one is charging the bang, the footage was shot down Holman Bros test mine and is used by CSM (Camborne School of Mines):

https://www.youtube.com/watch?v=405qtjail54

https://www.youtube.com/watch?v=-3NLi3-QXZE

The raise is essential for the extraction of the tin bearing ore, the ore is Cassiterite (SnO2)

The raise would have been driven at a steep angle in the ore vein to the half way point between the level it was started at and the next level up, typically down here that would be a height of anywhere between 120ft and 180ft, at the half way point the raise comes back on itself as it were which creates a dog leg, when the stope is started it starts at the dog leg where a bench is drilled and blasted out, this was called the point bench, subsequent benches would then be drilled and blasted progressing up the raise, which created a series of large "steps"

The miners, normally two of them, stand on a plank that's supported on two L pegs that are slid into two holes drilled into the foot wall side of the raise, for the first couple of rounds or so access to the platform is by iron ladder, from then on it's by chain only, a short ladder hangs off one of the platform support pegs, this gives the claw on the drills jack leg something to push against to advance the drill.

Looking at the films it appears the miner (Mark) has only drilled a short and small round for demonstration purposes, it starts off with the "cut" one of the "cut" holes has been reamed out, this was standard practice in a raise, the bang and det's he's using are the more modern stuff using igniter fuse millisecond det's, when I worked down there it was all electric det's with stronger sticks of bang, those dets had a longer delay time which enabled the reports to be counted when fired, this was important from a safety point of view as miss fires could be accounted for, the electric det's were connected in series, we rarely used stemming when charging up,we  just made sure the last stick of bang was rammed home really hard.

Spacer sticks (wooden) would be used in the "cut" holes back in the day using the stronger sticks of bang, that was to prevent the "cut" freezing up, this can happen when the blast is so intense that the small fragments of rock and dust created during the first milliseconds of the blast reform back to near solid rock due to the intense heat and pressure.


When I worked down there (Not the test mine, South Crofty mine) Mark would have still been at school, I had the honour of working with his Dad once for a short while, his Dad was a legend in mining circles down here.

All that for some solder and bean tins.....

Lawrence.

[pwdrive]

Here's another one by the same gang, quite unique in some respects and well done considering, filming/video underground is sometimes difficult, this footage is a testament to the old miners, it's The Great County Adit as it's known down here, it drains the workings at adit level and above of dozens of old tin and copper mines here in the county, it runs in various directions for a total length of around 30 miles and drained the adits of the tin and copper mines around the Gwennap, St Day, Scorrier area which at one time was the worlds largest producer of copper ore.

The adit's entrance portal which was refurbished some years ago is just below the hamlet of Twelveheads where I once used to live when working down the tin mine, from there the mine water eventually ends up in the river Fal.

https://www.youtube.com/watch?v=HHMU99eyPBE

I've also included more from the same crew that are worth a look, they're descending down to The Great Flat Lode in the Redruth/Camborne area, the lode wasn't flat (horizontal) as such but ran at around 40 degrees or so which is considered a flat lode compared to the normal 70 to 90 degrees encountered, these and other video's available from that crew provide a good record, Faraday etc might have got his copper wire via these mines, who knows.

Part 1:

https://www.youtube.com/watch?v=HIMZx-TX5-E

Part 2:

https://www.youtube.com/watch?v=ARnEfHL9Igs&feature=iv&annotation_id=annotation_260648197&src_vid=HIMZx-TX5-E

Lawrence.

[pamphonica]

Well, that's something different! Thanks Lawrence for opening a door on a bit of Engineering I had no idea about.
Definitely a mucky and dangerous job all round.
Shades of Blaster Bates etc!
Interesting indeed.
regards
Jeremy

[AlanBeckett]

Blasting isn't much of a problem provided you know it's happening. I was down a Yorkshire Pit a good number of years ago where they were running what must have been one of the last Advancing Faces in captivity. Unknown to me - bloody Amateur - they were blasting the Gate Roads in advance of the Face. I'd heard various shouting but as it didn't seem to be anything to do with me, and no-ne else on the Face was taking any notice, I ignored it. Big mistake! When it happened I nearly had a Heart Attack, much to the amusement of the Crew.

Much more 'exciting' was another Face I was on where the overlaying Strata was a thick band of Sandstone. That stayed up behind the Face until the weight got too much at which point a huge chunk would break off. The accompanying blast of air generally knocked you over.

Alan

[Radio Fixer]

Is all the vapour water when drilling the holes ?  Had to keep the sound low as the Missus is still asleep and may have missed it if it was said.  If not and its dust why has he no face mask ?

To me it was jobs and with modern tech could be made less dangerous to health.  But my wife is right against it and is glad its all gone as her Dad passed early with emphysema from the Yorkshire pits.

Open cast mining does leave ugly scars but at least men aren't down holes in the dark all day and up the Club most of the night ("laying the dust").  Open cast can be attractive once its over and made into fishing lakes.

Thanks for the leads, what a soft life I've had and glad of it .

Gary

[pwdrive]

Yes the vapour or "Funk" as we used to call it is a mixture of water and oil, that's the oil the miner in the video put in the steel oil bottle that was in series with the compressed air line, natural water vapour is in the compressed air, the separate water feed to the drill is there only to suppress dust that would be otherwise be encountered if drilling "dry", dry drilling was common back in the really old days (silicosis) We all drilled dry at some point, usually when drilling short peg holes for pipe supports in a tunnel and the water supply hadn't quite got there yet, the amount of dust produced doing that was a lot, but we didn't do it often but I pity the old timers that did.

Yes the blast wave can knock you back a bit if you're not expecting it and are too close, it doesn't sound what it sounds like in the movies either.

The old saying is if it can't be grown it has to be mined, Faraday, Hertz etc are all great hero's in our field but without the extractive industries nowt would have happened.

Health and safety has cleaned most stuff up, for the better I'd say but in some countries conditions are terrible, check out illegal gold mining or mining for materials for batteries we buy.....Makes you think.

Did you hold your nerve down down the pit Alan?

Lawrence.

[AlanBeckett]

I kept well out of the way Lawrence, and I can shift pretty quick when I'm Frit. The problem really was that nothing was 'Automatic' for me, unlike the real Workers, so I kept a close eye on them and followed suit as far as possible.

Oddly, the most dodgy moment was entirely above board, and supposedly safe. We installed a job lot of automatic controls on a face as a trial. One part of that was the the so-called 'Face Straightness' Control - it's best to keep the Face as straight as possible 'cause everything works better and there's less wear etc. The Controller 'Knew' where the Shearer was and which way it was going, and also what shape the Face currently was. It adjusted the Push-over to keep the Face straight, and to keep the Snake the right distance behind. Theoretically no-one was allowed within ten Chocks of the Shearer apart from the Driver, and he was only there to keep an eye on things in case something didn't work - it makes a nasty mess if the Front Drum hits a Chock Canopy, and is not encouraged. The reason for keeping people away was that the Chocks could move unexpectedly, and there wasn't wasn't much room when they were fully pulled in. When they're under Manual Control the Chockers would make sure no-one was in the way. Anyway, there was a Pre-Start Alarm on each Chock which sounded before they moved. So far so good and clearly 'Safe'. The snag was that the Controller also kept tabs on the Hydraulic supply, and if there wasn't enough to push over all the required Chocks it would leave some behind and sort it out later. So there you were, ambling up the Face minding your own business, when suddenly an PSA would sound and the Chock you'd just stepped on to would lurch forward. This was often followed by a few more as the Controller caught up. There were definite moments of 'Where am I going to go now?'.

All good fun, but I was younger then.

Alan

[pwdrive]

Yes, sounds good fun back in the day, never worked down a coal mine Alan, it's a different game as you will know, mining a raise was the wettest drilling job down here in the mines apart from shaft sinking, couldn't wear googles, totally impractical up a raise, just had to get used to the idea of being soaking wet for 8 hrs and being caked in granite chippings.

When Wheal Jane re opened a fair few coal miners came down here to work and settle, Jane was a very wet place, that concrete adit portal shown in the Great County Adit video was put in by Wheal Jane, not sure though if they used there own men or Thyssens or Cementation.

Lawrence.