Author Topic: Convoluted Pipe For Mine Entrance - Thoughts...  (Read 1538 times)

Offline notdavidgilmour

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Convoluted Pipe For Mine Entrance - Thoughts...
« on: February 15, 2018, 08:36:42 pm »
I'm currently digging a vertical shaft (in the corner of an existing back filled shaft) into an old lead mine, however, it keeps collapsing in and is getting quite dodgy being at the bottom of the hole, with big boulders falling on me.  The hole isn't really big enough to scaffold.  When I was helping on a dig out in Matienzo, they used a convoluted pipe to line a boulder choke.  Has anyone else used this method and if so, I'd really appreciate some advice on diameter of pipe used and anything else I should be thinking about.

Cheers,

Rob
I do it because i can, I can because I want to, I want to because you said I couldn't.

Offline AR

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #1 on: February 15, 2018, 08:49:31 pm »
You need either plastic twinwall or fibreglass twinwall, somewhere around 700mm diameter,but you also need to consider how to secure it. What's the original cross-section of the shaft and how far down is it ginged?
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Offline Rob

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #2 on: February 15, 2018, 09:57:42 pm »
Plastic pipe is good, as it lasts forever. Go take a look at Flower Pot in Stoney for an example of it used well:
https://www.flickr.com/photos/rob_eavis/albums/72157608862243605

But it can be expensive if you buy it new (i know, we sell it) so what you can beg, borrow or steal is likely to dictate what is "best" for the job.

And i agree with AR, it can be tricky to work with, compared to timber or scaf. For example, once you get the top section installed, how do you get the next piece down?!?
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Offline pwhole

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #3 on: February 15, 2018, 11:34:57 pm »
We've used 1m diameter twinwall pipe at Longcliffe, but of course have had the advantage of building the pipe entrance up from the bottom in 1m sections in a deep and wide crater, and then backfilling around it (though hand-chiselling the 30cm thick slab of calcite away to keep it vertical took some time), but as Rob mentions, inserting it from the top down could be very awkward. Chopping it into small lengths and then rejoining them below would be messy and time-consuming, but might work - it's hard to guess though without seeing your problem. Have you got any photos?

Offline The Old Ruminator

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #4 on: February 16, 2018, 09:24:48 am »
Yes double wall convoluted pipe works a treat. It is easy to cut and light to carry about. I used it to renew the old Balch Cave oil drum.




Ask around any big construction site as often sections get dumped. I got a 2m section for free that way. There is still half of mine behind the BEC hut if any one wants it.

Offline alastairgott

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #5 on: February 16, 2018, 11:25:51 am »
We've used 1m diameter twinwall pipe at Longcliffe

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Offline Juan

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #6 on: February 16, 2018, 12:26:09 pm »
Double-walled tube used by the Matienzo cavers for a second entrance to Cueva Llanío. Get the hole big enough then throw it down! :)






Offline Roger W

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #7 on: February 16, 2018, 01:18:17 pm »
That's OK if you can get the hole to stay open while you dig it out to its full depth...

But when you need to support the walls of your shaft as you go down, what do you do then?
"That, of course, is the dangerous part about caves:  you don't know how far they go back, sometimes... or what is waiting for you inside."   JRR Tolkein: "The Hobbit"

Offline SamT

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #8 on: February 16, 2018, 01:23:07 pm »
Why use a convoluted pipe, I prefer a straight forward one.

(Sorry)

Offline alastairgott

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #9 on: February 16, 2018, 02:10:59 pm »
That's OK if you can get the hole to stay open while you dig it out to its full depth...

But when you need to support the walls of your shaft as you go down, what do you do then?

I guess it depends on how final you want the walls of your shaft to be.

I guess the order goes.
1) Timber and Timber
2) Stone Ginging (modern Age, perhaps with some wizely placed Rebar in the Mix and Gummed up with Concrete to hold it in Place)
3) Scaff and Timber
4) Breezeblock Walls
5) Fibreglass Rings cut and secured to Slide down the inside of a shaft. (Like the original Titan Job)
6) Fibreglass Rings placed in their entirety.
7) Plastic Rings (like Longcliffe, Sold by Rob), but no chance of sliding any more inside, so cannot be used unless your going to slide smaller rings inside (it's possible but not perfect)
8 ) Concrete Rings (preformed) like the start of the Titan shaft.
9) Concrete Rings Poured (like the Titan Fix) into a former, like Fibreglass. Rebar can be placed in the sides of the shaft providing the support that your shaft requires?

Oh and I guess a rusty old oil drum should come somewhere in the list...
« Last Edit: February 16, 2018, 02:20:37 pm by alastairgott »

Offline alastairgott

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #10 on: February 16, 2018, 02:18:52 pm »
And Vertical Armco is probably on the list too, slot it down like scaff boards.

Offline The Old Ruminator

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #11 on: February 16, 2018, 02:49:22 pm »
The Balch rusty old oil drum lasted 40 years.

Offline The Old Ruminator

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #12 on: February 16, 2018, 02:51:35 pm »
Why use a convoluted pipe, I prefer a straight forward one.

(Sorry)

The convoluted pipe is much stronger.

Offline mole02

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #13 on: May 14, 2019, 12:12:28 am »
I’m thinking of using some of this vertically, but how do you attach a lid?
Does it mean the upper section has to be concreted/ginged?
Could be difficult

Offline mikem

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #14 on: May 14, 2019, 06:34:14 am »
Bolt it to the pipe.

Offline The Old Ruminator

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #15 on: May 14, 2019, 06:51:49 am »
Maybe a single concrete section at the top. Our pipe sticks up well above the ground but that works better than being flush with it. Depends on circumstances.

vurleyjuly2015 021 by Nicholas Chipchase, on Flickr

Offline mikem

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #16 on: May 14, 2019, 07:31:01 am »
Although if you haven't got space for scaffolding, you won't have space to get a pipe in either, need to make it bigger or use concrete...

Offline mole02

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Re: Convoluted Pipe For Mine Entrance - Thoughts...
« Reply #17 on: May 19, 2019, 06:06:07 pm »
Thanks Nick,

I've seen the entrance to Vurley and it looks just the ticket!