Mining subsidence and railway lines

[Wheldale]

Below is a link to a news article saying Daw Mill would have to close if the HS2 rail line got the go ahead. I know the pit has now closed, the Coal authority said that most of the reserves would have been sterilised.

www.coventrytelegraph.net/news/coventry-news/hs2-could-mean-closure-daw-3021833

I remember when the Selby coalfield was being developed the NCB paid 60 million quid to British Rail so that the rail link between Selby and York could be moved as it was directly over the coalfield.

What distance wise is given to either side of rail tracks, rivers etc to prevent subsidence?

[John]

Nov 14, 2013 15:45:59 GMT -5 Wheldale said:

Below is a link to a news article saying Daw Mill would have to close if the HS2 rail line got the go ahead. I know the pit has now closed, the Coal authority said that most of the reserves would have been sterilised.

www.coventrytelegraph.net/news/coventry-news/hs2-could-mean-closure-daw-3021833

I remember when the Selby coalfield was being developed the NCB paid 60 million quid to British Rail so that the rail link between Selby and York could be moved as it was directly over the coalfield.

What distance wise is given to either side of rail tracks, rivers etc to prevent subsidence?

No idea, but recall the blocks of coal we left under historic buildings, churches, bridges etc were pretty big, judging by the abandonment plans. We weren't allowed under consecrated land either..ie cemeteries..
I noticed on Clifton's abandonment plans there was a huge block of coal we couldn't touch under the power station next door, and a line of coal we couldn't touch under the main power transmission routes...There were no blocks marked under the River Trent that I've seen on the plans, although, the Trent sat in a major faultline.

To the north of us was Wollaton's workings, there is an untouchable block of coal under Wollaton Park, Lake and Hall.
Ironic, both pits worked well under built up areas of the City though, although Wollaton used narrow longwall faces under the University to reduce subsidence.

[bulwellbrian]

The Great Central line between Nottingham & Sheffield was seriously affected by subsidence and Mapperley Tunnel was also damaged so that it was closed. The red brick wall around Wollaton Hall also subsided opposite the university.

When I worked in the area lab I remember seeing mining plans showing pillars left for various structures such as Bulwell viaduct Bulwell St Mary's Church. The size of the pillar depended on the depth of the seam.

Incidently the NCB offices at Eastwood Hall subsided when faces were worked beneath.

[John]

Nov 15, 2013 4:40:30 GMT -5 bulwellbrian said:

The Great Central line between Nottingham & Sheffield was seriously affected by subsidence and Mapperley Tunnel was also damaged so that it was closed. The red brick wall around Wollaton Hall also subsided opposite the university.

When I worked in the area lab I remember seeing mining plans showing pillars left for various structures such as Bulwell viaduct Bulwell St Mary's Church. The size of the pillar depended on the depth of the seam.

Incidently the NCB offices at Eastwood Hall subsided when faces were worked beneath.

I take back what I posted, looking at the Piper seam abandonment plans, coal was taken under the park with just a large pillar left under the hall.

[welderpaul]

Out of interest John, and apologies for being slightly off-topic, but do you have access to (or know where to get) abandonment plans for the Selby Complex, specifically Wistow and Gascoigne Wood?

Thanks

[John]

Nov 15, 2013 13:41:48 GMT -5 welderpaul said:

Out of interest John, and apologies for being slightly off-topic, but do you have access to (or know where to get) abandonment plans for the Selby Complex, specifically Wistow and Gascoigne Wood?

Thanks

The Coal Authority, Berry Hill, Mansfield keeps all abandonment plans, they aren't cheap, but you can save yourself some money by searching for the relevant plans yourself and quoting the plan numbers. They used to be 12 quid a plan, each colliery had dozens of them, several pers seam as they are the original plans the survey team drew up.
They are also overdrawn over the surface map, so you can see exactly where the workings are in relation to surface features.

[Wheldale]

I was looking at a few websites about subsidence. Each coalfield is slightly different but generally in the Uk the angle of draw is about 38 degrees. The angle of draw is the angle of ground that is affected each side of the coal face. If a face is 700m deep then the amount of land affected by subsidence on each side of the face is 500m. Therefore a single face of 250m width at 700m depth would affect a strip of land on the surface about 1250m in width. I'll see if I can find anything about pillar widths.