Speedwell Bottomless Pit drainage......

Mrs Trellis

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I think this has been dye-tested to Peak cavern Gorge - does this fit in with Phil W's hypothesis of a parallel more northerly conduit carrying the BJM , Treak Cliff, Langcliffe (?) and others' water?


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See also John Gunn's article "The Underground Drainage of the Long Cliff to Goosehill Area, Castleton, Derbyshire" in TSG Journal vol. 19, pp 179-189, that looks at the dye traces done around Longcliffe in detail giving the evidence for the northern conduit.


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mch and AR any chance of you sharing some key findings on this thread? No prob if too inconvenient


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Pwhole's really the best person apart from the Prof himself to give you a good summary of what the dye traces are showing , the main thing I recall from it all is that there is good evidence for a separate conduit that takes water relatively rapidly away from the Longcliffe-Cowlow area.


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Sorry, I only just got home, and without digging all the data out, yes, there definitely seems to be a more northerly conduit, at least from the Longcliffe mines, and in terms of time taken to reach the resurgences, roughly a third of the time taken from the BP, which I think has averaged around 27-29 hours to start coming out, whereas ours was around 9 hours. Son of Longcliffe was the most interesting as it's relatively high up the hill, certainly compared to Longcliffe, which ends currently around the level of the canal, or just below it - but the SoL drain is about 50m higher, and yet water reached the resurgences remarkably quickly, suggesting a vertical route down to the water 'table' must be close by.

The possible inputs from WHC, BJC, TCC and maybe even parts of Rowter Hole are pure conjecture, but we know they don't go through Speedwell, and the shale boundary is in the way of BJC and TCC, though obviously the limestone continues beneath them, and they could meet the Longcliffe conduit lower down, underneath Goosehill Hall, rather than sharing the same one - dunno.

Other points of interest are that the strongest trace from SoL was actually from Peakshole Sough, and although Russet Well was the same time, was far weaker in concentration. The water in PS rises from a deep hole in the floor about 20m from the entrance, not from the far end, suggesting last-minute mixing of the various flows immediately afterwards.


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I shot these two bits of video this afternoon, showing the semi-permanent stream (in winter anyway) that flows down Cowlow Nick, gradually disappearing underground as it reaches the Longcliffe Pipe/Vein lines. This is where we did the red dye trace a few years ago, an hour after a green trace at the Longcliffe sump. Both came out at the main resurgences except Peak, though I seem to remember one didn't come out of Slop Moll - I'll have to dig out John's numbers and check, but basically it seems that either on the hillside or underground, none of this water is going via the Speedwell streamway - it's several hundred metres north, and the dip of the beddings (or the reef mounds) is largely toward the resurgences.



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I've posted these here before somewhere, but for continuity, these are the two traces we did in very wet conditions in December 2018. Dominika Wróblewska and Clive Westlake injecting fluorescein dye into the lowest point of Longcliffe (though it is a bit lower and further west now), and then Ben Tout injecting rhodamine into the Cowlow Nick sink an hour later - which more or less replicates more visually the two bitsof video above.

We had planned to do Son of Longcliffe with that, but the lower passage was completely sumped at the connection point, which we'd never seen before, and so we couldn't even get close to the swallow. It proved to be a fortuitous test though, as the rhodamine only came out of the rising in the floor of Peakshole Sough, and not Russet Well or Slop Moll. The fluorescein came out of all of them.





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Here's those 2018 results from John Gunn - he had fluorometers already installed at the resurgences at the time for some previous work, which proved handy, so we left them in whilst we ran these additional tests.


09/12/2018 12:45​
Longcliffe Mine​
270.0 g 40% sodium fluorescein​
09/12/2018 15:00​
Cowlow Nick​
320.0 g 20% rhodamine WT​


Resurgence Site
Peak Cavern Rising​
Slop Moll​
Peakshole Sough​
Russet Well​
Longcliffe Vein (Near Canal at Halfway House)​

Example fluorometer - Slop Moll: (5 mins sampling interval). No R detected. See table for F.

Injection Time
Hours until first detection
Concentration (ppb)
09/12/2018 16:25​
Possible first fluorescein​
09/12/2018 18:20​
More likely first fluorescein​
09/12/2018 23:20​
Peak concentration​
10/12/2018 07:05​
Back to pre-dye background​

Spot sample on 13 December had a small amount of F but no R

And John's comments on the results overall:

RW AWS: F but no R
First sample was 11h 45min after injection & contained dye
Concentrations dropped over time.
Last sample with dye 20h 45min after injection.
Last sample 46h 15min after injection.
Spot sample on 13 December had a small amount of F but no R

PS AWS: R but no F
First sample was 9h 30min after injection & contained dye.
2nd sample (11h after injection) had higher concentration [max?]
3rd sample lower and this trend continued
12th sample (28h 15 min after injection) was the last sample that contained dye.
From 29h 45min to 46h 15min after tracer injection there was no dye.

Speedwell Cavern
F visible in Near Canal on 13 December but concentration in LV beyond brick wall was down to 40 fluorescence units. No dye in a water sample from Far Canal.


Cowlow Nick:

All of the dye went to PS travelling very rapidly (<9.5 hours). It was all flushed through in <29 hours which has to mean it followed an open conduit with very little ponding.

Longcliffe Mine : A puzzler!
RW & SM: F arrived very rapidly (4-5 hours), concentrations peaked 10.5 hours after injection and the dye had cleared the system in <21 hours. Given these times it is very hard to believe the dye went via the BP and the Speedwell streamway. It should also be noted that although there was visible dye in the NC on 13 December the concentrations at RW and SM were only just above the limit of detection. This is consistent with dye leaking slowly from the NC into the BP and then being heavily diluted by the Speedwell stream.

PS: F was clearly present on the fluocapteur but concentration were markedly less than at RW & SM and there was no F in the water samples collected 11h 45min to 46h 15min after injection. Either the dye arrived very rapidly in a pulse OR it travelled slowly. The latter fits the previous tests.

PCR: The F on the fluocapteur was probably a remnant of dye injected at halfway House on 25 Nov but we know that Peak was flooded so it could be overflow water from the conduit to RW & SM.

These travel times are much faster than in the last round, presumably because the injection point was much lower in the mine. It is possible that there are three conduits:

• major open conduit to RW & SM

• minor conduit, with some delay to PS
• minor conduit with some delay to NC


F: Sodium fluorescein dye
R: Rhodamine WT dye
BP: Bottomless Pit
FC: Far Canal
LV: Longcliffe Vein input to NC
NC: Near Canal
PCR: Peak Cavern Rising
PS: Peakshole Sough
RW: Russet Well
SM: Slop Moll with very little ponding.


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One possible issue here (for us pushing further west in Longcliffe), is that we have assumed from our pretty accurate survey that the current dig face, if you can call it that, is heading beneath the near canal, albeit still about 10m east of it. However, if we managed to get dye into it, that suggests we're level - which would make sense, really. And it's possible in 10+m vertically we've made enough errors. But I've seen the water sink yet further down a small hole too tight to enter, at least another 1.5m, so I'm not sure really.

But all the results, the topography underground and the location suggest at least one other streamway in this vicinity. The miners would have probably mentioned it though, if it were easily accessible, and they didn't. There is a reference to miners in Longcliffe driving two fathoms 'in swallo', but where that is remains a mystery.

There are at least two backfilled shafts on top of the Speedwell Vent, the large igneous deposit just east of Cowlow Nick, and both are on the line of Longcliffe Vein. It's quite possible they were exploratory shafts testing the thickness of the lava cap, but equally they might have been checking for water. Puttrell and his mates got into a large dry cavern nearly 50m down from the Tellyers Venture shaft on the lip of Cowlow Nick in 1909, but they didn't mention any stream, but if Son of Longcliffe and Cowlow Nick both tested positive (and fast) to the resurgences, there must be one.
What of the Longcliffe Levy? Just along from the vent towards the road there was supposedly an entrance into the Longcliffe workings. Tony Marsden pointed out to me where he thought it was and it certainly looked probable. It would be higher in elevation than the canal in Speedwell though.


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But all the results, the topography underground and the location suggest at least one other streamway in this vicinity. The miners would have probably mentioned it though, if it were easily accessible, and they didn't. There is a reference to miners in Longcliffe driving two fathoms 'in swallo', but where that is remains a mystery.
My best guess on the "swallo" is it's the bit of mud-filled natural close to the end of the coffin level, which in turn is I think the "swallow gate" referred to being driven in some 1740s reckonings - it was driven towards that bit of natural, and has a very strange picked step-down at the inner end which makes no sense on an access level but does if you're wanting to drain your workings into a known bit of cave passage that takes water. The driving two fathoms could then be miners enlarging that passage to improve its drainage, the way to tell is to see how much they were paid for it; for example the driving of Chapeldale Sough at Flagg was remarkably cheap given the distance driven and Jim R suggested this was an existing streamway being modified, a suggestion I agree with. (No, I haven't found a way into that particular sough yet, though not for want of looking...)


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What of the Longcliffe Levy? Just along from the vent towards the road there was supposedly an entrance into the Longcliffe workings. Tony Marsden pointed out to me where he thought it was and it certainly looked probable. It would be higher in elevation than the canal in Speedwell though.
Phil and I have had a good look at the hillside round there, there's a few places that could well be run-in levels. I don't think the NT would be so keen on us digging them out though, it's one thing digging out shafts higher up the bank that most of the grockles won't even notice and making them safe in the process , but a level within obvious site of the path is a different matter, unfortunately...
There's nothing obvious underground either, though the eastern end of SoL might have had a level entrance in Cowlow Nick once upon a time?


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In a work van on my phone, so awkward typing!

I do wonder whether the blocked SoL entrance in Cowlow Nick could be 'the levy '. It's large and opens straight onto the dressing floor below it. However, the ruined building near the bottom gate did possibly also house another entrance, and the Levy then would be a crosscut at 90° to the veins - it's clearly collapsed and a backfilled shaft upslope would be an obvious ventilation and access solution for that.

The large area of disturbed ground at the base of the slope looks like extensive work on near-surface pipes - an obvious track from Speedwell leads to this area and splits into two at the disturbed ground. There's a possible blocked entrance in one or two of those hollows, and a possible infilled shaft by the footpath.

Also there is what appears to be blocked level directly above Speedwell that Nigel Ball showed me many years ago - this would follow the line of the canal, but I think it was above Little Winster Vein, so it's unclear what it might have accessed. Perhaps it was connected to the initial surveying work when the owners planned the canal level.

And I still haven't mentioned the Countess of Mazarene ;)
I can't find any references on the Forum via search but I know Phil and I have discussed this before.... Can we assume, or do we know that Anniversary Hall and Moss Chamber are not on Foreside Rake. It always intrigued me that the choke beneath the balcony might lead into the speculated route from the Bottomless Pit to the resurgences. And also that Middle Bank Pot was another way into the system. I don't know anything about the Countess of Mazerene 🤷🏻‍♂️


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Middle Bank Pot's been on the list for a long time, and would be an awesome long-term project - not least as it's only ten mins walk from the Chapel. Trouble is it's on Duchy land, and they didn't seem too keen on digs last time I asked - though to be fair they don't have a clue about anything like that, being very much a 'hands off' landlord, basically, and Joe Dalton manages the land. And I was asking about a slightly more public and (probably) contentious site. That said, they did allow the Titan connection dig, so it may be worth another punt - though obviously they knew what they were going to find there. I do have the right contacts at their office - it's just a matter of sweet-talking them from afar, as they're in London (obviously).

It's my personal feeling that Anniversary Aven/Moss Chamber is developed on the unnamed vein that crosses Cavedale - it's much closer than Faucet/Foreside Rake. This Google Earth grab shows the main vein lines and the Peak-Speedwell survey. The line of Longcliffe Vein, if projected in both directions, intersects the Victoria Aven area to the east (after almost passing under Middle Bank Pot en-route) and Winnats Head Cave to the west. Purely speculative, but the Halfway House 'workings' are mostly natural cave, as are those in Longcliffe, so it's entirely possible the vein cavities could extend further. That section west of Longcliffe was opened by the Bagshaws as a new title called 'Longcliffe West End' at precisely the time Ralph Oakden and partners completed the canal - and predictably began poaching from below.

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The access track from the Speedwell gate to the 'pipe workings' is clearly visible in these shots, and is probably the route used to take Bagshaw's 'Auld mare' up to the gin circle at Tellyers Venture. It was also the route used by us to get bags of sand and cement up to the Longcliffe shaft top in rucksacks, as straight up was nigh-on impossible.