Why Are Coal Mines Still Causing Subsidence?
The Industrial Revolution, outside of all the technological advancement and prosperity it brought the UK and the wider world, has had a lasting effect on our landscape, both above and below ground. At its height, there were 483 mining sites in the UK, employing over 500,000 miners and producing 177m tonnes of coal every year.
Coal mining is a hugely significant part of our heritage and the closing of the mines led to the end of a way of life that had supported generations of families for 150 years. Such was Great Britain’s demand for coal that the certain areas of the country, like South Wales, Yorkshire, Northumberland and the Midlands became pockmarked by mines.
The decline of mining after the 1950s has resulted in almost all of these mines being closed down, but our mining heritage is still having an impact on homeowners today, with some mines being the main factor in some subsidence cases.
Haven’t they all been filled in?
Yes, most of them have, but not all in ways that are structurally sound. There were several different methods that mining companies and local authorities used to fill in old mines, some of which are better than others:
- Vailing – This was the use of timber to block up shafts and side tunnels. These spears of timber were placed side by side across the shaft to cover up the hole. Finally, soil was packed onto it and it would be covered over. The reliance of this method on timber was an obvious drawback, given the eventual rot and decay of wood in wet or damp conditions.
- Backfilling – This method was even less well-thought out than the previous. It involved the piling and packing of rubble and waste into the shaft. This method fell out of favour in the mid-19th Century, and so isn’t that widespread. However, the fact that this happened before proper records were kept means that the locations of many of these backfilled mines are unknown and some buildings were built on these unbeknownst to the builders.
- Capping – This is now the preferred method of dealing with old mine shafts. The shafts are covered over with concrete and supported from the bottom and at various points down the shaft.
Filled-in mines are still dangerous
Even if the mine entrance has been filled in, the surrounding areas may still be dangerous. Mines extend far beyond their entrance, snaking all through the landscape and creating several weak points which could lead to collapse if enough weight is put on them or enough time lapses. This is why a professional survey of the area is absolutely crucial, because they have the expertise to spot signs of stress.
What can you do?
If you think your property is suffering from subsidence caused by coal mining then you should get in touch with the Coal Authority. The Coal Authority is no longer allowed to carry out mining and its main responsibility is handling subsidence claims and repairing or supporting old mine shafts. Use this map to see if your property is in an area with a large amount of coal mining. They can tell you if you need to order a mining report. The report provides the following information:
- Any mine entrances within 20 metres of the property’s boundaries
- Gas emissions from the mines
- Any reported coal mining hazards in the area
- Plans for future coal mining in the area
It will tell you if you are indeed suffering from coal mine subsidence, which you can then make a claim for if it has caused any damage to your property or land. Coal mining, though most of the mines ceased to operate several decades ago, is still having an impact today.