Mining Bell Pit in Garden - Query

[House7000]

Apologies if this is not in the right place, but does anyone have any experience of old mining works near a property?

We live in an area that has plenty of old mine shafts etc (you can see on the map checker multiple red X's) and have found a house which we may be interested in but it has an old Bell Pit in the back garden. It is not under the property, but it is in the garden. The seller has explained it is all covered by the Coal Authority should anything go wrong, but they have lived there over 40 years and never had an issue. By all accounts they just come and check it every few years?

They have all the documentation showing its been filled etc.

My immediate thought has been it's not worth it and to find somewhere else, but is it something to be less concerned about? A builder said to me it wouldn't worry him, but then other people have said it would put them off.

I know someone has pulled out as they weren't made aware of this at first. It is a house we are likely to stay in long term, but assuming people will be thinking exactly what I am thinking should we ever try sell again...

 

[JBR]

As far as I'm aware, bell pits didn't extend far from the initial dig.
I'd be interested in two things:
- how far from the house is it; and
- when, and in what way was it filled, according to the documentation?
You could also ask how deep it is, though bell pits were never that deep compared to later deep shaft mines.

 

[House7000]

As far as I'm aware, bell pits didn't extend far from the initial dig.
I'd be interested in two things:
- how far from the house is it; and
- when, and in what way was it filled, according to the documentation?
You could also ask how deep it is, though bell pits were never that deep compared to later deep shaft mines.

Thanks for your reply. I'll try find that out re what it was filled with. Is there a good and a bad way for it to be filled? Assume concrete is the best option.
I would say it's around 12 foot from the house, maybe a bit more. Is that good or bad?

They do have all the documentation on it so assume its detailed in there.

 

[JBR]

Thanks for your reply. I'll try find that out re what it was filled with. Is there a good and a bad way for it to be filled? Assume concrete is the best option.
I would say it's around 12 foot from the house, maybe a bit more. Is that good or bad?

They do have all the documentation on it so assume its detailed in there.

If it is filled by pouring in concrete, I'd imagine that's as good as anything.
12 feet from the house isn't that far. The pit might be 12 feet or more deep and, of course, at the bottom it is likely to extend 12 feet or more towards the house (depending on how brave the miners were!).

I think I'd also be tempted to have a word with the Coal Board too, and ask for their advice.

 

[endecotp]

I would say it's around 12 foot from the house, maybe a bit more.

Is that to the entrance, or to the edge of the underground cavity?

 

[House7000]

Is that to the entrance, or to the edge of the underground cavity?

This is what I dont know. We got shown the paper work at the time but I didnt get chance to read it in detail as we were viewing. The owners themselves pointed in the garden and said it's there but unsure on the cavity.

I guess the paper work may state this? Unless it just shows the entrance?

 

[JBR]

This is what I dont know. We got shown the paper work at the time but I didnt get chance to read it in detail as we were viewing. The owners themselves pointed in the garden and said it's there but unsure on the cavity.

I guess the paper work may state this? Unless it just shows the entrance?

Well it ought to, at least assuming that information is available. I have seen a map of an old coal mine in someone's garden in the south Lancashire area and, although it isn't a very large scale map, it is at least discernible where the opening is/was.

Have you tried asking the Coal board? I believe they still keep such records and should be able to help with advice as to safety regarding the adjacent buildings.

 

[House7000]

Well it ought to, at least assuming that information is available. I have seen a map of an old coal mine in someone's garden in the south Lancashire area and, although it isn't a very large scale map, it is at least discernible where the opening is/was.

Have you tried asking the Coal board? I believe they still keep such records and should be able to help with advice as to safety regarding the adjacent buildings.

I managed to get hold of the report from the Coal Board which was really helpful (also on a side note when calling them for extra questions they were great. More than happy to help and say they get questions like this all the time).

In summary it was capped circa 50 years ago, with a "slab placed below ground level". The report states that the main building is not at risk of subsidence from the mine entry as it is not within the area of possible ground movement.
The map itself shows where it is (which we knew from before) but only gives a rough guide, it doesn't say its 10M or 20M etc from the house and the Coal Board couldn't tell me this. They also said they couldn't say how far below it went, the report just states the depth of the shaft and the diameter of the shaft. But my question here was, is the diameter stated here simply the entry point or the width of the whole work. They weren't able to tell me this but I might try and speak to the persons whos name is on the report.

What do you think from the updated info above now?

 

[JBR]

From what I know, bell pits comprise a shaft of fairly constant width until they hit the coal seam. From there they work outwards to remove as much coal as they can without, hopefully, causing the roof to collapse. I don't know how long ago your bell pit was cut, but originally they didn't seem aware of the use of pit props. If they had decided to use them, the workings could have extended further, of course.

A 'slab placed below ground level' doesn't clarify whether or not they actually filled in the pit. There are, of course, other factors to consider such as the state of the ground in that area: rocks, clay, subsoil of some description? I assume the Coal Board would know about that.

What is the depth and diameter of the shaft?

In any event, as I expected, the Coal Board people seem to have been very helpful and if they have categorically told you that the main building is not at risk of subsidence from the mine workings, I should take their advice.

 

[Ian H]

I’d dig it back out and make an underground lair in it.

 

[IT Minion]

I’d dig it back out and make an underground lair in it.

Diy apocalypse bunker:

 

[JohnD]

I wonder if they blocked in with a concrete shaft mushroom?

 

[House7000]

From what I know, bell pits comprise a shaft of fairly constant width until they hit the coal seam. From there they work outwards to remove as much coal as they can without, hopefully, causing the roof to collapse. I don't know how long ago your bell pit was cut, but originally they didn't seem aware of the use of pit props. If they had decided to use them, the workings could have extended further, of course.

A 'slab placed below ground level' doesn't clarify whether or not they actually filled in the pit. There are, of course, other factors to consider such as the state of the ground in that area: rocks, clay, subsoil of some description? I assume the Coal Board would know about that.

What is the depth and diameter of the shaft?

In any event, as I expected, the Coal Board people seem to have been very helpful and if they have categorically told you that the main building is not at risk of subsidence from the mine workings, I should take their advice.

Sorry for the delayed reply. Thank you for your help on this. I'm comfortable with it now from various sources, yourself and of course the coal authority (and various docs).

Completely get why people get nervous about these things but having looked into it in detail in this instance all seems as solid as it can be and the official documentation from the coal authority back it up.

Unfortunately I still dont know for sure how big the mine is but records confirm it has been filled and capped and the house is not expected to be at risk.

Thanks again.

 

[JBR]

Sorry for the delayed reply. Thank you for your help on this. I'm comfortable with it now from various sources, yourself and of course the coal authority (and various docs).

Completely get why people get nervous about these things but having looked into it in detail in this instance all seems as solid as it can be and the official documentation from the coal authority back it up.

Unfortunately I still dont know for sure how big the mine is but records confirm it has been filled and capped and the house is not expected to be at risk.

Thanks again.

Are your insurers happy?

 

[House7000]

Are your insurers happy?

Yep. They said not an issue. Only becomes one if the house has ever suffered with subsidence (which this hasn't) or does so in the future when it then falls into the house with subsidence issue.

The presence of a mine shaft in the garden wasnt an issue in itself.