The South Yorkshire Coalfield.

Those members of the Yorkshire Naturalists’ Union – one of whose customary meetings has just been brought to a close at Doncaster —who form its section of geologists, yesterday, by permission of the owners, paid a visit to the collieries of Denaby Main, at Mexborough, and Cadeby, in the neighbourhood of Conisborough.

The occasion recalled the tremendous progress that recently has been made, and the still further efforts that are likely no distant date to be put forth, in the development of that portion of the South Yorkshire coalfield lying between Swinton and Doncaster. Looking at the success that has attended operations this direction in the past, is not a little curious to recall the doubts that appear to have at one time existed as to the presence of coal at all in that district. By the successful sinking some thirty years ago and the satisfactory working of the Denaby Main Company’s mine in the district such disbelief, where it existed, was conclusively set at rest.

So gratifying, indeed, have the results proved that the Denaby Company are busily engaged in sinking another pit a short distance away, at Cadeby. By this now undertaking it fully expected that the output of coal at Mexborough will be doubled, this at present amounting over 2,000 tons day, one the largest yields of any colliery in the country while also affording employment to twice many men, much that had been said to the contrary, convinced that coal was to found between Mexborough and Doncaster the Denaby Company resolved to venture the experiment, and with this object in view about three years ago they took from Lady Watson Copley a further lease of what is known the Barnsley seam, situate under the Sprotborough estate. By this arrangement—if expectations are realised, there reason to believe they will—an area of about four thousand acres will added to the coalfield in that part of the West Riding, extending from Swinton railway station on the Manchester, Sheffield, and Lincolnshire Railway to Doncaster Bridge one direction, and in the other from Conisborough and to Scawsby—a distance of about three miles. it being found impossible, with such an increased sphere of operations, to conveniently work these newly acquired Barnburgh measures from the existing shaft at Denaby Main, opening already it does ramifications under Melton, Barnburgh, and other places, it was immediately decided to seek powers to sink additional mine, with two other shafts at Cadeby.

It was in the operations in connection with the opening out of this new colliery—situate on the north side of the River Don, directly opposite the old Castle of Conisborough—that yesterday visitors were chiefly interested. An idea of the difficulties that have had to be contended with may formed from the fact that despite every mechanical appliance that skill could suggest, boring operations have reached depth of but 135 yards in the course of the couple of years the work has been in progress. Nor is much more than one fourth of the level that must be reached before coal can won —the actual depth being more than twice that at which coal won in the company’s pit at Denaby or Mexborough.

Some of the greatest difficulties that were feared have now, however, been, it is trusted, overcome, and under the superintendence of Mr. W. H. Chambers, the company’s mining engineer, the remainder of the work is likely to be comparatively free from trouble. Many of the feeders of water that were encountered not long after sinking operations were begun have now been successfully passed.

That the task has been arduous one is evident from the circumstance that in order to grapple with the encroachments of the water very heavy machinery and special pumps had to be designed, and that for so long a period as eight months several tons of water per minute were drawn from the shaft. Working at a normal speed of 23 strokes, the special machinery adopted raised 70,000 gallons an hour, and even then the water threatened to gain on the workmen. So difficult at one time operations, that as the sinkers gradually made their way down, the sides of the shafts were at each step secured against the inroads of water by iron tubbing, the necessity of which precaution being obvious from the fact that even at depth of much as 100 yards water had risen inside the tubbing to height within about fifteen feet the top. The pressure in the pipes at a depth of about seventy yards was so great that the joints gave signs of yielding, and the expedient was resorted of putting down tank and another pump at that distance, with the object the more readily gaining the water.

Though attended with so much danger—the depth of water strata Cadeby is, perhaps, without precedent in similar operations in South Yorkshire—there has been, it is gratifying to find, no case of serious accident, the operations, despite difficulties, being singularly free from mishaps of any kind.

Once the water has been passed , sinking will, of course, be comparatively easy, and progress possible at the rate of about ten yards week, and the Barnsley seam coal reached possibly within year after that trouble has been totally overcome.

At the Denaby Main Pit the coal measures are reached at about 450 yards at Cadeby it is calculated that they lie at depth of about six hundred yards from the surface, gradually dipping they extend eastwards. On coal being touched specially devised heading or boring machines , will be secured, that the course of the next two or three years—it is impossible fix the time with any degree of certainty—coal will be drawn to the surface, and employment found for about three thousand workmen.

The extensive output of Denaby, which between 10,000 and 11,000 tons’ weekly, will be doubled at Cadeby. At present 1,500 men and boys are employed at Denaby; the Cadeby Pit, when in full working order, will find employment for double that number. Already 300 men are employed in and about the works, 100 of whom are sinkers, working in relays of six hours each in both shafts, while the remainder are engaged in erecting the permanent buildings. The engines to be used in the working of the colliery, some of which are from the works of Messrs. Fowler, of Leeds, will be according to the most improved design and has perfect as possible. As to the apprehension there onetime seems to have existed lest the attractive stretch of country surrounding Conisborough and its castle would be still further destroyed by the presence of another pit, such objection will to a considerable extent be overcome, inasmuch as the mine will consume its own smoke system that will not only keep the atmosphere pure, but also add to the profits of the company by which the uses to which would otherwise nuisance may now be applied.

With the object of providing adequate carrying’ facilities to Hull—the chief export for Denaby coal—and other parts it is proposed lay different lines railway connected with the two collieries, in addition to the branch already at work under the Manchester, Sheffield, and Lincolnshire Railway. For this purpose power was recently granted by Parliament in a bill providing among its chief clauses for the construction of new line commencing at the present Denaby Main sidings, running beyond the workings that at Cadeby, afterwards turning to the north, and after passing through the villages of Pyburn and Marr, joining the Hull and Barnsley line at Wrangbrook—a distance altogether of about seven miles.

A junction is also proposed to be made with this line near to Sprotborough Hall, and this, by way of Hexthorpe and Balby, will effect a communication with the Great Northern and Great Eastern systems at Black Carr.

A measure embodying these proposals successfully passed a Select Committee at the House Lords last year, and operations giving effect to them will, it expected, be commenced in time to in readiness when the new colliery is full working. When that time does arrive it not improbable that steps will be taken even further explore the South Yorkshire coalfield by the sinking of a pit still nearer to Doncaster —so firmly is it now believed by many that coal is to found there, notwithstanding the opinion of some to the contrary.