mine shafts

Depending which books you read it is estimated that there were 3/5 thousand mine shafts in and around Wigan .It is funny the town never collapsed with the amount of coal that was extracted from under it. Are there any shafts which are only covered with timbers not capped I remember years ago there was a shaft on the left going up to the motorway bridge at Windy Harbour which was only covered with railway sleepers.

From an ex-miner too? The mind boggles!

I read that there is estimated to be around a thousand shafts within a 5mile radius of the town centre.

Says Two thousand in Davies's book, but I do not know if anybody is counting them, or just pulling figures out of thin air!

I should imagine a good percentage of these shafts where bell pits

Probably. Maybe count is also including Day Eyes.

I have read that earliest mention of coal in the district was in 1300's, at Burnhill, which apparently is either in Bryn or Ashton, but I have never been able to ascertain precisely where. So it is possible we are considering a long period over which mines may have been sunk. Even longer, if the Romans mined coal in the district, as some findings indicate.

Peter,
The mining did result in subsidence/collapse... hence the 'Flashes' - large bodies of water where land had sunk. Even the railway track disappeared in Pennington, Leigh. Moving on, some canal locks have twisted due to mining subsidence.
Ena,
There is an old OS map that indicates Roman mining north of the town, but I guess it would be surface or bell pit rather than deep pits.

OS maps are not reliable as sources of Roman remains. It is well known that they recorded such if locals described it as such. (With first edition, it is what you need for it to serve artillery targeting, ie an ordnance survey) There was no Archaeologist input to First Series. A lot of such errors have been logged.

For a long time, the argument was made that Romans were not using coal, as wood was still in widely available, and more easily got than coal. It is also much more difficult to engineer the grate and flue to suit coal: even at the Rainhill trials, all the locomotives were burning coke. Rocket was later converted: it took them a while to get the technology right for coal burn.

But Romans were making glass around Wilderspool, and firing clay rooftiles around Holt, so maybe they had industry that performed better with coal.

Somewhere, there is an account of when building required temporary diversion of the Duggie, and in the then exposed river bed they found something which, when cleared of river silt, appears to be remains of a Roman Mine. It consisted of linked polygonal chambers, which is similar to known Roman metal mines in Spain.

Sadly, it is the form of mine in which slaves could be employed, as they do not have the opportunity to destroy supports and bring down the roof on themselves and/or their captors.

PS An interesting example of the problem with OS maps.

You can find the assumed site of Coccium shown on OS maps.

It isn't Wigan!

Come to that, it isn't Coccium either!

And, guess what: it isn't Roman!

Ena... thank you for that very interesting and educational narrative. Greatly received.
Yes, Roman mining on OS (and other more relatively recent offerings) is rather speculative. All of your text is noted and agreeable.
The question of Roman activity in Wigan is still a work to be concluded... ancient writings offered a scenario. More relatively recent excavations have given us a better picture.
The earlier excavations at the Wiend revealed a Roman warehouse or perhaps factory/workhouse - in this area a store of mined coal was encountered. This can be regarded as perhaps 4 alternatives;
Coal was mined in Wigan
Coal was mined nearby
Coal was transported to Wigan for local use
Coal was temporally deposited in Wigan for use futrher on.
But, all is speculative... I hope future archaeology might give us a more accurate delineation of our town's history.
I expect every single person will have their own agenda, but I am always persuaded or given direction form actual facts.

The subsidence is still going on. I used to be employed by a firm that grouted up old coal workings to stabilise the ground. The problem is there are a lot of unknown mines. The simplest was when coal was found close to the surface and they dug the coal out from what is known as a bell pit due to the shape. They didn’t use supports and dug out what they could safely or until the sides started to collapse. They’d then put an upside down bush in the hole and back-fill it ready to collapse many years later. Some small shafts were never recorded and again, the upside down bush trick was often used. The failure of the top of a working is usually a conical shape in cross section and if you ever get them chance to go to an opencast mine that’s digging through old coal workings they are often visible as text-book examples. The old props and other equipment are also usually clearly on display.

Shaft.

Shaft.

Another result of all the mines closing is that ground water levels are rising as the workings are no longer being pumped. The lack of water extraction for industry is also adding to the problem, so for example the Mersey tunnels are having to pump more and as mine water dissolves solvable ochre from the rocks where it comes to the surface brooks that used to run clear are turning bright orange. The ochre can be treated, there are a number of sites around the UK doing this. there is a large one near Hindley and another at Ashton. There is also one near Walkden removing the ochre from the canal there which has famously been orange for a very long time!

I've heard that before, that mines not pumping water out adds to the ground water level rising. And the last time I heard it, I couldn't get my head round the claim, as I still can't. Surely, if you imagine there never having been any mines, so no sub-surface voids, would we be under water by now?
Also, if the old mines are full, they'll take no more water. If they are taking no more water wouldn't that reduce underground water movement, therefore reducing subsidence in sandy areas like ours? Laaaaike?

Unfortunately because a lot of the strata around Wigan /St Helens and beyond is sandy even today after many years of mining and our good old English weather the water soaks into the ground and washes some of the sand away Even though mine tunnels could be many hundreds of yards below ground and many miles of them if they started to collapse or flood then the void above the tunnel could have fractures in the rock to allow water to seep back to the surface many miles away.When the Quaker pit was working they would pump water out and also sand thus there was many a small sink hole in the fields between Birch Grove and Billinge Road and at one time even made two old mine shafts on Leyland Green Road to sink.

I dealt with one collapse near Poynton where an old working collapsed beneath a brook. The brook was swallowed by the collapse and due to the layout of the old workings underground flowed downhill and re-appeared several miles away after some time once the capacity of the old mine was exceeded.
For many years ground water levels were kept artificially low due to extraction for industrial processes and to keep the mines dry. Once pumping stopped the levels are still returning to natural levels but in places are finding adits, culverts, mine workings etc and the water is coming out in places that it never has before. As the workings whether intact or collapsed aren’t watertight and within the bedrock they are leaching the ochre from the rock and bringing it to the surface. There was an opencast in Ashton in Makerfield where the sump that drained the site looked like tomato soup, the water was treated, went through a couple of settlement ponds and off into the environment as high quality. Interestingly, the Winter Hill collieries (not Wigan I know) were designed to drain naturally and after they had closed the water was tested and found to be of very high purity and was tapped as a drinking water supply for the surrounding area. Fred Dibnah did a bit of a survey in some of the remaining workings up there, and occasionally they collapse, I have met two people on the moors that have fallen through and survived, one was saved by his ruck sack stopping him going down but he’d still been up to his neck in stinky peaty water.
Some of the Aspull collieries were forced to close when one of the other pits stopped pumping and they couldn’t deal with the rising groundwater.