Author Topic: Warning - major collapse at Odin Mine  (Read 22551 times)

Offline pwhole

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Warning - major collapse at Odin Mine
« on: February 19, 2011, 12:34:07 pm »
Martyn G, Jane and I visited Odin last night to begin a long-term photographic project, only to find a serious and potentially very dangerous collapse has occurred in the entrance section. We were last in a month ago, so it's fallen since then, but it would be interesting to see if anyone's been in more recently, to try and work out exactly when this happened. I know others have been in 2-3 weeks ago, so it's happened within the last fortnight, definitely. Needless to say, if it had collapsed during a trip, there could have been a death, as it's on an unprotected section.

It's right at the base of the first handline climb, approx 50 metres into the mine - the entire floor has disappeared into a crater approx 2.5m X 1.5m in size, leaving a ragged drop of approximately ten metres straight down - the walls of this hole are a very, very crumbly shale/rock mixture and are still falling in. Having a drill with us, we managed to traverse across it and just about made the climb up (trickier now with a ten-metre hole directly beneath you) to rejoin the normal route to see where it's all ended up, and - it gets worse - it's all landed right in front of the stempled passage that links to the Cartgate, and has also taken out the first two stone stemples, which are now somewhere in the pile.

Luckily, the passage itself is intact, but the heap of large deads, gravel and mud that now partially blocks it is very, very unstable, and is still moving. Therefore, the stempled passage (and, by implication the Cartgate and beyond) are currently not safely accessible.

By good fortune, the 'pit of uncertain depth' mentioned in the guide at that point is right beneath the heap of rubble, and so much of it can be safely dumped in there, once the situation has been assessed and stabilisation work (if possible) has been done. But at the moment, it's very, very dangerous, and we would recommend that folks please keep out until the relevant authorities have been informed (which we're doing right now) and the situation clarified.

For more information, please contact Martyn Grayson, DCA Projects Officer, on 0797 695 3089.

There's some photos of the collapse here:

http://www.pwhole.com/photo_galleries/private/Odin_Collapse/collapse.htm

Offline Mark

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Re: Warning - major collapse at Odin Mine
« Reply #1 on: February 19, 2011, 01:57:49 pm »
Probably one of the most unstable places in the Peak,

Before the pit is backfilled, please check that it doesn't connect with the stuff lower down in the mine which could be destroyed.

Mark

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #2 on: February 19, 2011, 02:33:10 pm »
On the official survey, it's just drawn as a short pit that terminates just under the level - I've never bothered looking into it as a result, and never fancied climbing out again if it was dodgy 'round the corner'. At the moment, it's very dangerous to check down there, as the rubble pile is slipping down it already due to gravity and slope. I always assumed the survey to be very accurate - however, we found some sections last night in another part of the mine that are marked as 'run in' on the survey, and they certainly aren't now (although not exactly roomy) - whether subsequent post-1975 digs have opened them up again I don't know, but it didn't look like they'd been dug recently.

Also, workings in and off from the roof section of the Bell Chamber (including an apparent shaft) are not on the survey either, so it may have been a less than thorough exercise - dunno really. The handline climb is not well-surveyed at all, as it's much steeper and more difficult than the map suggests, with one or two completely vertical sections, and nothing like the gentle slope one might expect on a first visit.

What worries me about this collapse is that it's in an area most would think very stable, and the frightening part is that it's right where folks would naturally drop off the handline climb to the floor - possibly it's years of that happening that's caused this. There won't be any more jumping off that anymore.

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #3 on: February 19, 2011, 03:25:27 pm »
One other point to mention is the hole in the 'floor' near the top of the handline climb (after the last overhang), also seemed a little larger to me, and may connect to a rise pictured on the survey between the slope down to the stempled passage and the blockage itself. If so, that would be a similar drop, and possibly more, if that fell through. I shone my lights through it. and it's definitely hollow beneath, but we were all down by then, so no way of checking for a voice/light connection.

Offline Brains

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Re: Warning - major collapse at Odin Mine
« Reply #4 on: February 19, 2011, 03:36:10 pm »
One other point to mention is the hole in the 'floor' near the top of the handline climb (after the last overhang), also seemed a little larger to me, and may connect to a rise pictured on the survey between the slope down to the stempled passage and the blockage itself. If so, that would be a similar drop, and possibly more, if that fell through. I shone my lights through it. and it's definitely hollow beneath, but we were all down by then, so no way of checking for a voice/light connection.
The internal shaft before the pitch/after the climb? Remermber a voice/ light connection from when it was  P bolted... but that was a while ago now!

Offline Big Jim

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Re: Warning - major collapse at Odin Mine
« Reply #5 on: February 19, 2011, 03:55:11 pm »
Phil, everywhere Martyn goes there seems to be a collapse.  Coincidence????? ;)

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #6 on: February 19, 2011, 09:50:46 pm »
Jim - I think the old man's just getting jumpy about his bedroom getting discovered after all this time and is attempting to distract us ;)

Brains - this rise I mean is after the pitch down, then down the slope east. Just before you'd climb up to enter the stemple passage, there's a large vein above, with what looks to be an internal shaft with stemples. I suspect this may reach up to the top of the handline climb, which in my mind now is more of a 'floating staircase'.

Offline Roger W

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Re: Warning - major collapse at Odin Mine
« Reply #7 on: August 19, 2011, 11:27:59 am »
Any more news on this?
"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 pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #8 on: August 22, 2011, 11:42:28 pm »
Not yet - I was hoping we might get an update soon, but so far, no news. With the summer being so dry, it would be interesting to see whether the backfill in the entrance level has stabilised. Trouble is, if it hasn't, there's not much can be done, apparently - though getting a JCB down the front end to dig out the original cartgate entrance and make it safe for entry would be my preferred option...

Offline Cave_Troll

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Re: Warning - major collapse at Odin Mine
« Reply #9 on: August 23, 2011, 10:02:51 am »
sadly it seems to be around 125m from the bus stop above the arched exit to the collapse in the end of the cartgate chamber.
It'd take more than a JCB

Offline Roger W

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Re: Warning - major collapse at Odin Mine
« Reply #10 on: August 23, 2011, 10:33:29 am »
I think he was suggesting using a JCB to unblock the entrance to the cartgate so that people could get in to the workings from that end - not drive the digger along the cartgate to the collapse!
"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 Cave_Troll

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Re: Warning - major collapse at Odin Mine
« Reply #11 on: August 23, 2011, 12:21:50 pm »
I know. I wasn't talking about the new collapse, but the boulder choke that forms the end of the cartgate chamber.
its possible that its 125m of rubble from the road into the system

Offline SamT

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Re: Warning - major collapse at Odin Mine
« Reply #12 on: August 23, 2011, 01:44:06 pm »
Hang on - its only 100m from the road to the entrance of the system, so I refuse to believe its 125m from the East end of the Cartgate to the side of the road where the cart gate most likely originally came out to surface. 

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #13 on: August 23, 2011, 04:35:02 pm »
The original cartgate entrance was just outside Odin Cave, albeit about 3-4m lower than current ground level. It ran in a deep trench to the original crushing circle, and when the road was built, the cartgate route was culverted over - there's a photo of it in 1943 before it was covered up completely by the bus terminus.

In 1927, John Royse sank a shaft in the gorge (at the junction with Widowers Vein) and got somewhere near the cartgate (he claims he came through the arched roof), but it appears he was still not through completely, as there are no holes in the arching at all, other than the crosscut to the Bell Chamber (or Hallom's Deep Shafte?). He also said lots of shale blocked the way - again, no shale in the cartgate, but the workings in the roof of the Bell Chamber are in shaley stuff, and we found a shaft at the back end of those going down...

That John Royse shaft eventually collapsed, and could be the source of the current blockage - I have no idea who put the large railway sleeper prop in, for example - maybe Les Salmon or someone? The shaft was less than 64 yards from Odin Cave, as I've measured the first two meers, and they just reach the start of the slope proper - that shaft was just after the first meer (ie 32 yards). I've got photos of all this stuff, and some of it is on Mine Explorer.

So I don't think it would be that big a job to excavate down into the mouth of the gorge and find the cartgate level again. The Bell Chamber is most likely to hold a connection chance. Also, Knowlegates Sough level must still be intact under the road...and why doesn't anyone ever check the Widower's Vein entrance...? ;)

Offline Roger W

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Re: Warning - major collapse at Odin Mine
« Reply #14 on: August 23, 2011, 05:27:50 pm »
But how much of this would involve digging on NT land?  And what would they have to say about it?
"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 pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #15 on: August 23, 2011, 05:51:10 pm »
All of it.

I can't speak for the NT obviously, but I did make the suggestion to someone there (only half-jokingly) all the same, as I don't think it's that far-fetched, personally. Leaving it to rot and collapse even further is a far worse option. What happens when the whole lot starts going? Then you have a 200m deep, evil chasm right next to their prettiest showcave, with no way of ever filling it in safely.

Offline Cave_Troll

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Re: Warning - major collapse at Odin Mine
« Reply #16 on: August 23, 2011, 06:15:57 pm »
my survey says its 125m from the bus stop to the end of the cart gate and another 50 m to the entrance pbolts.

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #17 on: August 23, 2011, 08:12:51 pm »
Tim

Whereabouts on the surface do you think corresponds with the cartgate blockage? The first large pile of rubble, or the second?

Also, the crosscut from the cartgate is meant to be on Widowers Vein, though at a lower level to the gorge. I've never been far west along that passage, as I was believing the survey too much, which says it's blocked. But in the gorge on the right, looking uphill, there's clearly a lower-level fissure below the current Widowers Vein that's been deliberately blocked with rocks and a large tree trunk.

If that, or the higher-level entrance could be shown to connect internally with the lower-level passage (perhaps via a collpased winze), that might produce another route into the cartgate from surface? I have a plan of John Royse's dig on paper from an old PDMHS article by Chatham - he worked on the shaft, and went down there with Royse. It's bang on the junction with Widowers vein, marked with a big 'X'...

PW

Offline Cave_Troll

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Re: Warning - major collapse at Odin Mine
« Reply #18 on: August 23, 2011, 11:40:27 pm »
this is what i'm working from



i think the end of the cartgate chamber is somwhere level with odin cave

Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #19 on: August 24, 2011, 12:14:45 am »
Well, the Gank Mouth, point 0 when measuring the meers, is right bang on the edge of the cave - the large auger mark that signified the title is still visible. So it's likely the old entrance was also thereabouts.

The 1920 photo in the frontspiece of Jim R and Trevor F's bulletin shows a much deeper trench at the mouth of the gorge, and early accounts describe entering a low arch then along a passageway with a boarded floor. That could well be the section on the other side of the blockage, and the current cartgate combined.

What still puzzles me is exactly what the arching's for in the cartgate. If it's too hold back deads from earlier stopes, why aren't they accessible from higher up? It can't be merely decorative. The parallel passage behind is in solid rock, so it wasn't to keep those separate. Endlessly theorising...

Offline SamT

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Re: Warning - major collapse at Odin Mine
« Reply #20 on: August 24, 2011, 01:02:56 pm »

Hmm - I was going on this survey..

http://www.peakcavemonitoring.org.uk/images/stories/Castleton/odin%20mine.doc

Are you sure you're interpretation of  where the bus stop is on the survex file is correct - maybe it starts by the shaft and crushing circle. 

Hmm - maybe I'm wrong.

Given that the area is right on the border of the largest active landslip in the UK, it wouldn't surprise me if the original entrance to the cartgate was through shale, and now entirely lost.


Offline pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #21 on: August 25, 2011, 12:30:52 am »
As far as I know, it was in limestone - the vein occupied the gap we see now, and the dip of the limestone under the shale doesn't really start until the last hillocks on the right, looking up the gorge. The higher-level workings in Amy Gutter vein, and in the roof of the Bell Chamber are on the shale boundary and they seemed reasonably intact (for shale) when we looked - and they're the earliest workings in there, making the current situation incredibly frustrating - we were just starting to make some progress in there. The workings inthe Bell Chamber roof are not on the survey at all, and were far more extensive than we expected on the one visit I made - mostly crawling about, but lots of small up and down workings leading off.

The article I have by HE Chatburn states categorically that the mine-owners blew up the entrance (in 1869) when it was abandoned, and they also blew a crosscut near the cartgate, which may the Widowers Vein blockage mentioned previously. I only wish I had a digital copy, but it's on paper - I'll try and get it scanned, as it has a scaled map of the site, with the line of the cartgate on it right to the road. It was in an old PDMHS bulletin from 1962, but they haven't transcribed that one yet.

Offline Roger W

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Re: Warning - major collapse at Odin Mine
« Reply #22 on: August 25, 2011, 03:05:56 pm »
I only wish I had a digital copy, but it's on paper - I'll try and get it scanned, as it has a scaled map of the site, with the line of the cartgate on it right to the road.

Probably teaching grandma to suck eggs, but if the map is in black and white, set your scanner to scan in black and white and save the file as a .gif  -  it takes up less space than a colour .jpg file and doesn't introduce coloured shadows.

I'd got it into my head from somewhere that the cartgate went right under the road to somewhere near the crushing circle, but with the entrance blocked.  Guess it's a lot more complicated than that, though...   :(
"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 pwhole

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Re: Warning - major collapse at Odin Mine
« Reply #23 on: August 25, 2011, 09:04:50 pm »
Roger

I don't have a scanner, that's the problem! I'll try and photograph it instead.

But no, the cartgate was open to day from Odin Cave onwards to the crushing circle - the original track just crossed it, I think, and because the eventual road altitude was much higher, the cartgate was culverted over - the original gigantic spoil heaps (they had cottages on top of them they were so large!) were used to make the road ballast. I've got a good comparison photo of 'old' Odin with now, and the difference in height between the two ground levels is astonishing - these photos seem no longer available from the main ME site, but managed to find the link:

http://www.mine-explorer.co.uk/view_picture.asp?id=29635

And also visible is a seemingly deep hole going down into the gorge - presumably the entrance was blown in just beyond this point.

What also puzzles me is why Royse and co didn't just use the entrance (called 'Hanging Rither' on the old plans) we all use today. I have another article by Mike Smith, again from early 60's PDMHS notes, about a section 'recently opened by Rother Valley Caving Club' accessed via an inclined shaft at the end of the entrance level - however, it's unclear whether he's talking about the large 37m west pitch, or just the smaller east pitch we use to access the cartgate, as the following description seems to mix the stempled passage with another, that I don't recognise.

But either way, it suggests that the cartgate has only been accessible from the current entrance for the last 50 years at most. I've asked Jim Rieuwerts about some of these ambiguties ages ago, but think I need to press him some more!

One other image at the bottom of this page - a slightly fanciful but vintage illustration of Odin before the gorge was completely cut out, complete with cartgate entrance...;)

http://www.rotherhamweb.co.uk/h/waltheof.htm

Offline Roger W

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Re: Warning - major collapse at Odin Mine
« Reply #24 on: August 25, 2011, 10:04:05 pm »
An excellent series of pictures there!   :thumbsup:

The two views side by side have really got me thinking!

I visited there a few times when I was a kid at school - that would be in the '50s - and have vague memories of scrambling up to Odin cave to peer in (yuk! - muddy!).  And I recall visiting again with my own kids when they were small (1980's?) and thinking that the ground in front of the mine and cave had been greatly altered and levelled off then.  Unfortunately my memory is sadly less than photographic, but I do now remember thinking that some big changes had taken place since I had been there last.  Would this all have happened around the time that the road across the face of Mam Tor was finally closed?  I presume that would be when the bus turning circle was created.

And when did the land become National Trust property?

Maybe someone with a better memory than mine can throw some light on the matter!
"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"