Warning - Devonshire Mine entrance subsidance

DCA

Active member
Over the last day or 2 a small gap has opened up beneath the door at Devonshire Mine. Overnight this has grown to a much larger gap and there is evidence that the area has become unstable and is at risk of collapse. The deads that sit under the door have become dislodged and the whole area is settling. Please use the Upper Entrance (old show mine) to access the mine until further notice.
Safety warnings have been posted inside the mine and out and the landowner down the lane is aware.
DCA will try to establish a course of action as soon as possible once the movement has ceased. Please remember that this entrance is on a filled in shaft, so it would be wise to stay clear for now in case the shaft is attempting to un-fill itself!
Thanks to PICA member Tom Monck for the initial notification.
Pete Knight
DCA Projects
 

Gritstone

Member
Just to clarify, is permission required to use the top entrance? I thought it was out of bounds in someone's garden. The last time I was in there was a new metal gate fitted. It was possible to get around the side of this but looked like a infill was due to be added.
 

paul

Moderator
See https://peakdistrictcaving.info/home/the-caves/derwent-south/devonshire-cavern
 

Pete K

Well-known member
Gritstone said:
Just to clarify, is permission required to use the top entrance? I thought it was out of bounds in someone's garden. The last time I was in there was a new metal gate fitted. It was possible to get around the side of this but looked like a infill was due to be added.
Things have moved on a lot since those days. See DCA website for current access info. Although a combination lock was initially fitted to the Upper Entrance, this has been removed and will stay off for the time being.
 

Pete K

Well-known member
Sorry, just seen that the Devonshire listing on the DCA site does not seems to have been up updated when we added the other entrances to the access agreement. I've just submitted the following text to correct that:
"Devonshire Upper Entrance is not mentioned on the listing. This does not require permission to use. A combination lock may be present, if so the code will be ****. There are plans to convert this Upper gate to a Derbyshire Key in future. The shaft from surface above the main chamber and just inside from the Upper Entrance is also approved for access."
 

LarryFatcat

Active member
Pete K said:
Sorry, just seen that the Devonshire listing on the DCA site does not seems to have been up updated when we added the other entrances to the access agreement. I've just submitted the following text to correct that:
"Devonshire Upper Entrance is not mentioned on the listing. This does not require permission to use. A combination lock may be present, if so the code will be ****. There are plans to convert this Upper gate to a Derbyshire Key in future. The shaft from surface above the main chamber and just inside from the Upper Entrance is also approved for access."

Maybe the entry could also include a description of where the "Upper Entrance" is, inc a grid reference?
 

royfellows

Well-known member
Thanks for all this. I often use the place for testing new lamps.
Please keep the thread updated on latest on the new 'sinking', I am enthralled!
 

AR

Well-known member
If you want to be completely accurate, it's about 100m further up the hill, where the path divides in two, take the right-hand branch then head into the deep cutting.
 

AR

Well-known member
Would anyone be able to go into Devonshire in the near future and visit the chamber with the fill cone from the shaft and get some pics? It's most likely that it's on the move, hence the subsidence above at the door, but I'm out of action with a knackered ankle and Pete K is busy with work right now so someone giving us a better idea what's going on at the bottom of the fill would be a great help in coming up with a stabilisation plan.
 

phizz4

Member
As we use the cave a lot with our scout groups i owe we owe it to the community to try to help. i can get there on Thursday or Friday evening if that is soon enough?
 

phizz4

Member
I went down Devonshire this evening (Friday) to have a look at the damage and take some pictures. What's the best way of communicating the pictures and my findings to those that need to know?
 

ttxela2

Active member
I have a vague recollection of accessing a small chamber directly underneath the entrance through a smallish tube like crawl, I'm guessing it's the roof of this that is collapsing?
 

phizz4

Member
A quick report. I can send a more detailed report and pictures but I tried to do that earlier on this topic and it hasn't posted, don't know why. The pack below the door at the lower entrance seems to have moved forward and down. I'm guessing surface run-off from the slope leading to the entrance. There seems to my non-engineering eye, to be no downward slumping. Some material is going down the muddy slope to the left of the entrance (looking out) that leads to the lower series but that seemed unchanged (although it looks like some hanging death in the ceiling but I think that has always been there). Went to the base of the infilled entrance shaft, I believe (behind the large rectangular block) where there are two upward chokes. The left one is jammed blocks which don't look to have moved. No sign of new debris on the floor. Slightly right is a much looser looking infill. Again, no sign of collapse but quite muddy and water has obviously been trickling down. Recent shoulder surgery (rotator cuff tear) prevented me from investigating small holes. There is still a padlock on the upper entrance gate but a hole to the left of the gate was easily big enough to allow me in.
 

Pete K

Well-known member
Drop me an email with some pics if you can please!
projects@thedca.org.uk
Cheers!

Additionally, I need to go take a look at Devonshire gate myself really, to start planning a fix. Anyone free later today or on the 15th or 16th to keep me company?
 

Pete K

Well-known member
phizz4 said:
A quick report. I can send a more detailed report and pictures but I tried to do that earlier on this topic and it hasn't posted, don't know why. The pack below the door at the lower entrance seems to have moved forward and down. I'm guessing surface run-off from the slope leading to the entrance. There seems to my non-engineering eye, to be no downward slumping. Some material is going down the muddy slope to the left of the entrance (looking out) that leads to the lower series but that seemed unchanged (although it looks like some hanging death in the ceiling but I think that has always been there). Went to the base of the infilled entrance shaft, I believe (behind the large rectangular block) where there are two upward chokes. The left one is jammed blocks which don't look to have moved. No sign of new debris on the floor. Slightly right is a much looser looking infill. Again, no sign of collapse but quite muddy and water has obviously been trickling down. Recent shoulder surgery (rotator cuff tear) prevented me from investigating small holes. There is still a padlock on the upper entrance gate but a hole to the left of the gate was easily big enough to allow me in.
Ah, well someone unknown has put a new lock on then!
Sound's like the shaft is not running in then, good news. Probably just needs a team with some rebar and load of mortar to build a new wall up where the orange ladder currently sits. Anyone local fancy heading this job up?
 
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