Conisbrough & Denaby Main
Heritage Group

Coal measures were formed in the Carboniferous Period, millions of years ago.  Plate tectonics and erosion in the Ice Age led to these layers of coal to eventually became exposed  at the  surface.  These seams of coal are gently inclined to the East and South so that they become deeper in that direction.

Coal was discovered in West Yorkshire centuries ago where the seams reached the surface and was mined by digging small pits to follow the seams of coal as they dipped below the ground.  Most of the these seams were only one or two feet thick but a large seam about ten feet thick was found near Barnsley.  This seam was high quality and worth the expense of extensive development.  Shafts were sunk down to the Barnsley Seam, but to follow this resource, shafts had to be sunk deeper below the surface the further south and east they went.

From information from mines previously dug , it was estimated that the Barnsley Seam would be about 400 yards deep in the area of Denaby.  But there was no guarantee that the coal would even exist as no bore holes had been previously sunk to support this.  It was a huge gamble that a venture in Denaby would make a profit.

A consortium of business men decided to form a company and sink a shaft on the West side of Denaby near the River and Railway as they could use both to transport any coal found and they hoped the coal would be closer to the surface.

Digging started in 1863 and they encountered problems with water almost immediately, haveing to take expensive measures to control the water and be able to continue digging. Two shafts were dug and the coal measure was eventually found just over 400 yards below the surface four years later.

Once in production, profits from the mine were so great that they decided build a second pit South of the village of Cadeby , just to the East of Denaby Pit, which was sunk in 1889 and the rest as they say is history.

Denaby Pit taken from Railway crossing

Cadeby Pit taken from The Craggs
Taken from newspapers of the area
Denaby Colliery 1885 Evictions
6th May 1885
Yesterday the Constabulary ejected several topmen and their families from the colliery cottages at Denaby.   No opposition was offered, the people behaving in a most orderly manner.   Only officials and a few sick whom it would be dangerous to remove are now left in possession of the cottages.  The evicted families took refuge in several tents which have been erected at Mexborough and Swinton. 

Yesterday a woman named Thompson who died several hours after being ejected was interred, the funeral being attended by about one thousand miners.
10th July 1889
Satisfactory progress is being made with the sinking operations in connection with the new Colliery at Conisbrough.  Over one hundred men are employed already and the Company's workmen have sunk the shaft already about sixty feet.  It is anticipated that when a certain depth has been reached the sinking will be entrusted to private enterprise for which tenders will be asked. So far comparatively little water has been met with.  The concrete beds for the permanent engines are about completed some thousands of tons of material used to build them up. 
 In connection with the work a lot of new cottages are being put up on the Conisbrough side of Denaby Main, which in the course of a year or so will become an important centre of industry:  500 cottages is the smallest number mentioned as being about   to be put up.

10th September 1889
Cadeby Pit Shaft sinking
The Denaby Main Colliery Company are making extensive progress in sinking operations at the new pit at Conisbrough, the shaft having reached a depth of well over one hundred feet.   Nothing like the amount of water is being met with now as was expected would be the case, though of course, the pumping engine is constantly working.  An immense bed of concrete has recently been finished near the mouth of the shaft and on it will be erected the machinery that will be needed in excavation.                                                                               
A large number of houses are being built by the Colliery Company midway between Conisbrough Station and Denaby Main and building operations are also in full swing in Conisbrough.

Coal reached at Cadeby
24th January 1893
After sinking operations extending over three years and eight months, coal has been reached at Cadeby.  This pit is situate about a mile from the Denaby Main Colliery and is owned by the same Company.  Whereas coal was found at the Denaby Main shaft at a depth of 450 yards the distance at Cadeby is 750, which is 150 yards deeper than was contemplated.