Old Bolsover Colliery.
SK 44683700.
The land on which the new building development is situated, the site of the old station and Jam factory there are two shallow shafts identified on British Coal plans. When I went to the depository at Mansfield to view the plans there was nothing on file but the position of the shafts and to note that coal had been mined by two shafts.
There appears to be two shallow shafts working in very shallow coal seams or seam, according to legislation having two shafts is either after 1862 or if earlier a very forward thinking company. Why sink two shafts when one will do. The colliery nearby, Bathurst Main Colliery would be similar in seam section etc to that worked in the area of the station. There is nothing in the area on Sandersons Map of 1835 but fields running off Cobster Lane. Farey makes no mention of it in his survey of 1790.
The area in question is situated where the lines from the station all converged so surely the railway company would not have left the area worked out without first filling in the shafts or moving the line away from the mined area. Or at least taking some remedial action.

The shafts have been or will be filled in and the topsoil has been removed and the coal exposed and removed as the seam in the workings had become friable or rotten with age.
The Lancashire, Derbyshire & East Coast Railway was planned and built between 1891-1896 so the colliery must have been prior to this but one can only say it was mined between 1862 and 1891 but with no certainty.
Highmain 23-27 inches.
Mainbright 8 inches.
Wales 11-16 inches.
Confusingly the Wales may be called the High Main and the High Main the Silkstone.
Geology of the Country Around Chesterfield, Matlock and Mansfield. Smith, Rhys and Eden. H.M.S.O.) pp. 189. 178. 180.183.185.187-8.190. 253-4. 311. (Carr Vale).

Colliery Site.

Site of former iron footbridge over railway. Looking North.

Looking east towards tunnel.
Cutting is now filled in.

Seam & workings exposed for removal. (Harold Allsop).
The Hartley Colliery Disaster of 1862.
A disaster happened at Hartley colliery in Durham in 1862 where blackdamp (formed by the decomposition of coal, timber and other materials containing nitrogen and carbon dioxide and compounded by the exhalation of air from humans) killed 204 miners. The mine used only a single shaft partitioned in two by a brattice. The mine was ventilated by a flow of hot air up one side of the shaft produced by a furnace in the pit bottom which heated the return air. The heavy cast-iron beam which supported the surface pump broke in two and crashed down the shaft destroying the brattice causing the ventilation to stop and also blocking the shaft bottom causing the men who were entombed there to die slowly from suffocation. The men and boys were dead when rescue teams cleared the shaft bottom and found them. The later act of Parliament prohibited the use of a single shaft and at least two means of access were to be available to every mine, many local enterprises sank drifts underground between mines to comply with this legislation.