I was sorting through some photos the other day and came accross these. As far as big boys toys go this needs to be seen working to fully appreciate the power, so I've put them in order to give a broad outline on this monster bit of kit.

Three stages in mining an orepass using a raise boring machine.

Step 1. A chamber is first excavated and then the Raise Borer motor head is installed.

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Next an 11inch (275mm) hole is bored down to the target destination.

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This simple cross section illustrates the basic set up of the process.

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The drilling head is removed and the reaming head is attached to the bottom of the column. Once secured, the whole machine is set in motion and and the reamer grinds its way up to the top of the column. The last few feet are taken out using traditional methods.
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That's the one from Wheal Jane late 1970's, tell you what I wish it was still possible to see shafts that this thing cut.....

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Yes that's right. At the time it was supposedly the largest ever used in europe and was custom built by Robbins for Carnon Consolidated's Wheal Jane Mine. The shafts this thing bored were clean as a whistle and, being used for ore passes, did not 'Hang-up' like a traditionaly mined raise with rough sides.
As you say, it would be nice to see these shafts once again.
Even if the tin price goes ballistic (It's on it's way now at $25,150!!) I cant ever envisage anyone considering Jane as a viable prospect, let alone reopening it.
Still.....Lots of other places to try down here! 😉

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I saw a picture of one of these monsters which was used at Tynagh mine in Galway Eire. Huge.Will try and find the picture. :thumbsup:

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http://www.directindustry.com/industrial-manufacturer/boring-machine-65010.html . Hope this is a useful resource for you other readers.

That was certainly a piece of kit, if you remember the Chilean miners that were trapped, they used a similar machine to bore the shaft to rescue them, the difference being that the reaming head had to be pushed through as opposed to pulled back.

Tara Mines (Boliden) in Ireland are currently boring two 850m vertical ventilation raises at 4m diametre as return airways to the SWEX area of the mine.

There are a number videos of raise boring operations on YouTube – for instance.

Dave

http://www.directindustry.com/industrial-manufacturer/boring-machine-65010.html . Hope this is a useful resource for you other readers.

Wrong machines, not suitable for the job!

Oooooh - upside down tunnelling machine!!! Seriously though, that reaming head is reminiscent of Bruntons tunnelling machine's business end.

Thanks for the pics and info.

Grahami

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🅱I've never seen a raise boring machine, but the two 1000 tonne ore bins at Boulby were initially drilled with one, then drilled and fired and mucked out using the bored hole, much was dropped to the bottom and loaded onto a belt. The access hole just inbye of the ore bins was also drilled using the same borer, around 36 inches diam. All three holes were 100 feet deep.

Yeah, seen videos of these things going. Superb way of making a shaft, *if* you can easily get to both top and bottom!

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It gets interesting when the reaming head gets jammed when it is halfway up a raise and refuses to budge!

It gets interesting when the reaming head gets jammed when it is halfway up a raise and refuses to budge!

I bet. How would you free it? batter the top end of the shaft with a big digger bucket?

The machine is rather dependant on good strata. I can imagine ploughing it through a 20m thick water-logged shale bed part way up would be a minor irritation. But then one would hope you'd be aware of the presence of something like that before you start...

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It gets interesting when the reaming head gets jammed when it is halfway up a raise and refuses to budge!

I bet. How would you free it? batter the top end of the shaft with a big digger bucket?

The machine is rather dependant on good strata. I can imagine ploughing it through a 20m thick water-logged shale bed part way up would be a minor irritation. But then one would hope you'd be aware of the presence of something like that before you start...

Fortunately this was the second of a pair of 4 foot raises set at 20 feet apart. Miners very carefully mined a cross-cut between the two raises at the horizon where the head was jammed. The aim was to punch through into the open raise so the head could be freed

Unfortunately either the surveyors got it wrong or the miners did. Either way the head was destroyed when they broke through exactly where it was. At least they were able to lower the smashed remains to the level below.