UK patio event: Mine shaft or sink hole?

Subject: UK patio event: Mine shaft or sink hole?
From: GUEST, ^*^
Date: 15 Mar 16 - 07:41 AM

Scorrier house patio falls into 300ft mine shaft

Who in their right mind would build anything this close to a mine shaft? It looks rectangular, so that seems to be the case. We see these kinds of surprise holes opening up after heavy rains in karst regions of the US (where sink holes are commonly found).

Someone had to know that was there, right? Is this a house built by a shady developer? What's the story?

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST, ^*^
Date: 15 Mar 16 - 07:48 AM

Ah - more. ""If you go back to 1750, the area was completely different there were dozens of engine houses and hundreds of shafts in the area, which probably looked a bit like a desert.

"It would be something almost unrecognisable, probably more like a foreign country than what we know.

"As mines closed, many put very large bits of timber across shafts and backfilled them, thinking this would be safe.""

So builders aren't obligated research the property, look at those old maps, before starting construction?

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Raggytash
Date: 15 Mar 16 - 07:52 AM

http://www.dailymail.co.uk/news/article-3491246/Amazing-pictures-300ft-Cornish-mineshaft-captured-drone.html

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Dave
Date: 15 Mar 16 - 07:53 AM

Problem is it is a tin mine over 200 years old, the company which owned it long disappeared and any documentation with them. Its quite common now to expect a mining survey with a planning approval application, if the general area was known to contain historic mines. But with a mine closed over 200 years ago, and a patio built maybe 50 years ago when regulations were less rigorous, who knows? The patio may well not have needed planning permission. There are companies these days who do a lot of business finding and capping these mines.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Keith A of Hertford
Date: 15 Mar 16 - 12:07 PM

There are many lost workings and shafts, and there have been many similar cases in Cornwall.
One opened up in the car park of my mother's flat in St.Agnes.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Keith A of Hertford
Date: 15 Mar 16 - 12:14 PM

"He estimates there are more than 15,000 shafts in Cornwall, some nearly 200 years old, many of them not shown on any map."
http://www.independent.co.uk/news/uk/collapsing-mineshafts-put-cornish-homes-in-danger-1548979.html

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Nigel Parsons
Date: 15 Mar 16 - 03:17 PM

From the original link:
It is thought to be an 18th Century remnant of a tin mine and will be recapped with concrete.
I know the hyphen is dying out, but sometimes it provides clarity:
Re-cap: To place a new cap on.
Recap: To summarise the main features.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Black belt caterpillar wrestler
Date: 15 Mar 16 - 05:31 PM

Our house is supposed to have a coal mine 75' below us according to NCB records. In fact when our water borehole was drilled it found it at about 46'.
We have several depressions in the fields around us caused by older mines which the NCB have no records of. Some of them have old mine trucks and rails in them still where they were abandoned.

So, in short, there are a lot of mine workings down there that have no records left about them.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Mr Red
Date: 16 Mar 16 - 03:31 AM

One place I worked at. I got there for the interview and they apologised for the temporary nature, no carpet etc. Pretty new building, but they had had a flood recently. While I was working there I popped down to the petrol station for vittals and asked them how they faired with the flood - they replied. "I dunno why they built there, it was always known as the Flood Meadow"! Quite a little industrial estate and - geeze - a sewage pump! You gotta larf, innit?

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Stilly River Sage
Date: 16 Mar 16 - 11:17 PM

The search for a look at or inside some of these mines via Google tends to lump all sorts of Old World mining activity together. Images of tin mines in Wales next to salt mines in Turkey. This looks like a promising starting point. There are some small local history web pages with sketches of children and women working in the mines, and cramped dangerous conditions for all. One of the first places I remember reading about mining in the UK was, of all places, in college when I read Lady Chatterley's Lover. Who knew it was part environmental disaster story?

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Derrick
Date: 17 Mar 16 - 04:29 AM

Simply entering "mining in Cornwall" into google or yahoo search gives a variety of sites and articles devoted to Cornish mining.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Iain
Date: 17 Mar 16 - 07:30 AM

Definitely a mineshaft. There are thousands of them around all unlisted or poorly recorded. Stoke on Trent has very shallow coalmines under part of it's streets. I remember seeing one core come up with part of a pit prop and a neatly drilled section of railway line, back in the nineties. I have also nearly lost rigs down un-mapped bell-pits in the welsh valleys, and also hunted for concrete capping blocks over minseshafts with a 360 excavator. A backhoe is a bit too close and personal if there is uncertainty as to the integrity of the cap. In north Wales, in the old copper mines, shafts would often be covered over with tree branches and waste material placed on top.This is fine when recent, but after a hundred years the adits become lethal to traverse.
Even in rural Ireland, out in west Cork, mines rear their ugly heads. The road from Durrus to Balledehob had a collapse several years ago due to subsidence of old copper/barytes mine workings.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: leeneia
Date: 17 Mar 16 - 08:45 AM

The owners of that house certainly seem lucky. Apparently the shaft doesn't connect to any underground rooms, and the sides of the shaft look good and solid. If they backfill the shaft and cover it with concrete, they ought to be okay.

How fortunate that the shaft was under the patio and not under the house itself.   

Iain, thanks for your insights.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: Stilly River Sage
Date: 17 Mar 16 - 09:53 AM

Backfilling a 300 foot deep shaft would take a LOT of fill. I suspect another cap would go in place instead, engineered to last another 100 years.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: JHW
Date: 18 Mar 16 - 04:57 AM

On a tour of coal pits near a National Trust property we were told a common method was to jam a small tree, whole, into the top of the shaft and backfill over.
Back when they would have nothing which could span the opening and be supported on surrounding solid ground but thats not a problem now.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Musket
Date: 18 Mar 16 - 05:17 AM

Excellent "wetland" bird sanctuary at the end of the lake at Clumber Park, National Trust estate near Worksop. A plaque shows how it "appeared" a few years ago.

My pride of course is in being one of the dozy buggers who caused it to happen, albeit a good few years earlier and at a depth of 3,000'.

Subject: RE: UK patio event: Mine shaft or sink hole?
From: GUEST,Derrick
Date: 18 Mar 16 - 06:30 AM

South Crofty Mine has just been rescued from administration by a Canadian company,mining may yet return to Cornwall.


http://www.plymouthherald.co.uk/Future-bright-tin-mining-Cornwall-rescued/story-28948856-detail/story.html