Visit to Cadeby Main – The Largest Colliery In Yorkshire – Pit Top Inspection

December 1896

Mexborough & Swinton Times December 4, 1896.

Cadeby Main.
The Largest Colliery In Yorkshire.
Past, Present, And Future Developments.
Special, Descriptive Article.

Among The Surface Works.
A Downward Rush Through The Darkness.
Mont-Blanc In The Bowels Of The Earth.
An Engineering Triumph.

It is seldom that in connection with a purely commercial enterprise like a colliery one can find a thread of romance, yet if the legend speaks truly, there is an element both of historical and romantic association in connection with Cadeby Main Colliery, the new pit of the Denaby and Cadeby Collieries, Limited.

The story goes that Oliver Cromwell, to whom more than half the discovered mischief wrought in history has been attributed, planted his cannon on the site now occupied by the pit headgears, when he conceived the idea of blowing Conisborough Castle about the ears of the daring follower of the Stuarts, who then held it for Charles I. And regarding Conisborough Castle as the original of the Castle of Torquilstone, which Sir Walter Scott in ‘Ivanhoe’ tells us was besieged by the Black Knight with whom were Robin Hood and his crowd of outlaw’s Cadeby Hill, where on now stands the colliery under discussion, becomes the point from which the assault on Torquilstone was delivered. If legendary lore was only half as reliable as the average fact therefore Cadeby Colliery would be surrounded with associations sufficient to give excuse for a good long article without any attempt to describe the concern as it exists to-day, but unhappily for the fate of romance, there is a doubt whether either the Black Knight or Oliver Cromwell were at Cadeby in their lives, or if they were there, were guilty of the conduct which historical fiction in the one instance and fictitious history in the other has attributed to them.

One may feel sorry that Conisborough Castle was not the scene of the imprisonment of Wilfred of Ivanhoe and Rebecca the Jewess, and that it was not from the now sadly altered hill-brow of Cadeby that Coeur de Lion in disguise came to their rescue; but one can hardly regret that Oliver Cromwell probably did not train his artillery from Cadeby Hill in order to annihilate the Cavalier stronghold on the opposite side of the Don, for the reason, that Cromwell has already enough laid to his charge in the shape of Vandalism; and secondly, that it would hardly be redounded to the credit of Cadeby Main if its site had ever been used for the purpose of destroying one of the few remaining monuments of the feudal age of chivalry. But if these rumours of romantic or historical association are not justified their existence at all event, lifts Cadeby Main above the ordinary, and even regarded as a colliery only makes it something out of the common.

The sinking operations at Cadeby Main were commenced in 1889, in 1893 the Barnsley seam of coal was reached after a descent of 750 yards from the earth’s surface. Between the end of 1893 and the middle of 1896 the colliery was the subject of sorts of rumours, some of them exceeding in extravagance the Oliver Cromwell story alluded to. But it was all along an open secret that after sinking to such an extraordinary depth, after contending with some tremendous obstacles in the shape of water, and the nature of strata, through which the shaft had to be sunk, the Denaby and Cadeby Company had touched unlucky, and had almost drawn a blank.

For month after month the huge pulley-wheels over the downcast shaft had little to do, and all the speculations in the world as to what was the reason why they were not put in use only served to increase the general mystification and the universal conviction that below the surface at Cadeby Main events had not been shaped themselves exactly as the proprietors of the colliery desired. At the bottom the coal for which the pit had been sunk, was certainly found, an of excellent quality and thickness, but in one direction, and that from which it was anticipated, the greatest yield of coal would come, it worked out with uncommon and decidedly unsatisfactory promptitude, that is to say that almost before the pit bottom developments were completed, the Barnsley bed in the westerly direction from the shaft terminated in a ‘fault,’ a huge bed of rock which in this instance was both a failing and a fault.

The coal from this point played for nearly two years an elaborate game of hide and seek with the management, in which the latter after an experience that would satisfy the ambition for anxiety, of most men, won. They had come down a distance of 750 yards in a perpendicular direction to find the bed of coal which had dodged them, and they then went about 700 yards through the rock in an almost horizontal direction before they came upon the treasure they were seeking. From the bottom of the shaft a drift was made at an incline of one in two and a half until the Swallow Wood bed of coal was reached. This accomplished a longer drift at an incline of one in six was carried up to the Swallow Wood bed, and from here a third drift was taken at an incline of one in two to the Barnsley bed, which was ultimately discovered at an elevation of about 150 yards above the pit bottom. It was, it will be admitted, only a fair return to the company for all their trouble and outlay, that the coal, when discovered, was an exceedingly fine bed, and one that bids fair, when the work of developing the mine is completed, to repay those interested for their previous ill-fortune.

This, then, is the secret of the Cadeby Main, and is the explanation of the mystery which has surround the colliery almost from the day when the coal was first found.

But this is to be a description of the colliery, and if the preamble be extended there will be precious little left to describe. I went round and about the premises, up and down, last Friday afternoon in company with Mr W. H. Chambers, the general manager of the company. I was fortunate in having him for my guide, for he took the greatest possible pains to make everything clear to me – and let me admit he had some trouble. Our tour of inspection began at the extreme end of the surface workings beyond the coke ovens which are extended almost to Conisborough tunnel.

Here it was explained to me that the contemplated work of building another row of coke ovens was at present suspended owing to the opposition of some neighbouring landowners, who by interfering to prevent the diversion of a footpath across some fields, had compelled the company to go to Quarter Sessions for the necessary leave, pending which the whole of the work here was at a standstill. It appears that the landowners in the neighbourhood of Cadeby Colliery are rather prone to place as many obstacles as possible in the way of its development for the company wish to acquire land for the purpose of constructing a reservoir on the hill above the colliery and cannot procure it upon any consideration.

Coke Ovens

This, however, is by the way. The tour of inspection began properly at the coke ovens. First we inspected a row of ovens recently completely, and which are being dried before being charged. Then we passed to the ovens in use, the principle of which was explained to me by Mr. Chambers. They are of the bee-hive pattern, and they make a better quality and a larger quantity of coke than the old type of oven, with less smoke and a minimum waste of material. When the ovens are charged, fired, and hermetically sealed the gasses which are given off by the charge enter a flue which connects one oven with another. Thus when one oven is fired the gas which it gives off serves to fire its neighbour, and so on while when all are fired this circulation of gas keeps them all at a uniform temperature.

The necessary air to aid combustion is admitted to each oven through a star ventilator, but the current first passes through the gas flue and thus reaches the interior of the ovens in a heated state. There are at present a hundred ovens at work, and so ingeniously are all the by-products of the process utilised that but comparatively, little smoke issues from the chimney which serves these bye-products to even greater use.

A plant is now being erected to deal with the products obtainable from the gasses which the manufacture of coke occasion. The gasses will come from the ovens in a cool state and from them will be extracted hydro-carbon oils, amoniacal liquors and benzine from the latter of which aniline dyes are obtained. As the gasses become heated by this process they will be sent back to the ovens to assist in the manufacture, while the cold gasses that are left after the extraction of the bye-products will be taken cold to burn under the boilers. The Colliery Company manufacture three classes of coke, steel coke, furnace coke and foundry coke. When the ovens were first erected. Mr. Chambers was told he could not make a silk purse out of a sow’s ear, and he would never make foundry coke out of the Cadeby coal. He replied that he would try and the result is that the company is turning out a foundry coke which is equal to the best Durham coke and finds a ready market. A peculiar feature of the result is that the coke on the top of the ovens is lighter both in colour and in weight, than in the bottom of the oven which is heavy and dark in appearance.

Slack Washing

The slack washing which is part of the process of coke manufacture was inspected next. At present the slack is taken to the washing machine in wagons, but it is intended to convey it upon a gauntry in trams that will discharge themselves, and then return automatically to the pit bank. On delivery at the washing machine the slack is thrown into hoppers from which it is carried by elevators and screened to prevent any that is larger than required being taken into the washer . What is dealt with ultimately is very small, and even this is separated by the process of being disposed of in two grades. The washer is a beautiful adaptation of a well known scientific fact.

The slack is discharged on to a layer of felspar laying on a grid over which a constant stream of water is poured. This is agitated by the motion of a number of pistons, and the coal having a lighter specific gravity than the dirt, which is mingled with it, rises to the top of the water, and is carried with the flow over a sill whence it pours into a tank from which it is again carried by elevators. The dirt, being heavier than the coal, sinks to the bottom of the water, and passing through the felspar and the grid, is conveyed away. Before this treatment the coal contains 14 per cent of ash, and afterwards only three per cent., which being included in the coal cannot be washed out of it.

The capacity of the slack washing machinery at present erected at Cadeby is 600 tons per day. I have said that the coal when washed is carried into tank which extends the whole length of the building used for the washing process. Here again the variation of the specific gravity of the material aids the machinery, the very fine and consequently lighter dust rising to the top, and being carried off by one set of elevators while the coarser and heavier material is taken from the bottom of the tank by another set of elevators. These take the washed coal up to the top of the building, where it is tipped into bunkers with a storage capacity of about 300 tons. Here it drains, and when required is discharged from the bottom of the bunkers by a slide into the pans which convey it along the top of the coke ovens. The ovens are filled through a trap on the top of each by drawing out the slide in the bottom of the pan in which it is trammed from the slack washer.

The future development of the colliery will see the erection of an apparatus for drawing the ovens automatically. At present it takes a man two hours to draw an oven, but by machinery it will be possible to do it in a quarter of an hour. This new plant will include screens for the coke, which is now screened by forks with the addition of manual labour. To screen coke by machinery is regarded as difficult, but Mr. Chambers has overcome the difficulty, and has designed a machine which will do the work swiftly and economically.

Stores and Workshops

A visit was next paid to the stores, a range of lofty and commodious buildings, where are kept the supplies of oil, ropes, cordage, bolts, nails, and in fact all the minor accessories of a colliery. Adjoining it is the saw mill and joiners’ shop, girdered over head for the drying of timber. Next come the blacksmiths’ shops and forge. The first shop contains a steam hammer, and the second is fitted up with lathes, screwing, punching and planning machinery, and is connected with the adjoining shop by a travelling crane, capable of lifting 40 tons, and which is set in motion with the greatest ease from the floor below without any climbing up above and consequent risk of injury to the men. All the mechanical engineering work required for the pit can be carried out in these shops, and it should be said the men engaged in making or repairing tubs are enabled to do all their own iron work and screw their own bolts.

Engine House

After the inspection of the stores came a visit to engine house, where one is at once struck on entering by the colossal solidity of the machinery. The engines have 45 inch cylinders, with a seven foot stroke. They are fitted with the patent steam reverses, automatic, and Daglishes’ trip gear. The winding is done upon a spiral drum, which runs from 18 feet up to 33 feet, and weighs 90 tons without the shaft. With each revolution thirty three yards of the rope are wound up.

The engines are at present being worked with a pressure of 80 lbs. of steam, but they can be worked with a boiler pressure of 100 lbs. They will then wind the entire length of rope in 45 seconds, and allowing 10 seconds to change and five seconds for leakage, it will be possible to make a draw a minute. As each draw brings up four tons of coal, 240 tons will thus be brought to bank in an hour. 3,360 tons in a day of 14 hours, 18,480 tons in a week of five and a half days, and 964,960 tons in a year of 52 weeks. I watched the engineer make a draw while I remained in the engine house, and more remarkable even than the ease with which he could start and stop the huge machines was the fact that when in motion they caused absolutely no vibration of the building with which they are situated.


Leaving the engine room we proceeded to inspect the boilers, ten in number. It is intended to increase the number by twenty-two, making thirty-two in all. The boilers are fired with coal dust, containing seven per cent. of ash, so economical is the management, and yet as Mr. Chambers pointed out this gives an excellent fire. Behind the boilers is the huge steam exhaust of the drawing engines, and when this is blowing off steam it resembles nothing so much as an Iceland geyser.

Electric Lighting Plant

Boilers are not, however, interesting objects to examine, and we left the perspiring firemen, to inspect the electric lighting plant. It is intended to carry the electric light down the pit, and for this purpose the electric engine house is fitted with four dynamos of 500 lights each. The engines driving the electric plant are duplicate pair, so that on the event of accident the other one could be brought into use. In the electric lighting house is a very fine switchboard supplied by Messrs. Mather and Platt, but which was fitted up by the colliery company’s own electrician. Behind it is more than a mile of cable, and it may be said that the whole of the plant, both on account, its completeness and condition, is greatly to be admired.

Fan Engine House

The fan engine house was visited next. The mine is ventilated by a Shiele fan, with a capacity of 500,000 feet a minute with a five inch water gauge. At some future date it is intended to duplicate the ventilator and engines in order to guard against any obstruction or accident in the pit, and when this is done the capacity of the machinery will be 700,000 feet a minute with a seven inch water gauge. Mr. Chambers caused special care to be exercised in the construction of the ventilator engine. She was built according to his own specification, and is designed so as to reduce the risk of a breakdown to a minimum. Some idea of the strength of the engine may be gathered from the fact that the valve spindles are 3½ and 3 inches in diameter, a strength which the engine builder. I am told, described as ridiculous. The engine is provided with metal packing so that it never has to be stopped to pack the valves, and evidently every possible precaution has been taken to make this important detail of the mine’s machinery perfect. The revolutions of the fan are recorded by an automatic counter, and a rather curious fact is that the belt of the engine by constantly running in one direction has charged itself with electricity, and on coming in contact with metal throws off a shower of sparks.

Furure Development 

With the fan engine house almost the whole of the works above ground had been completed, but before preparing for the descent of the mine. Mr. Chambers gave me some interesting facts regarding the present and future development of the pit. It is intended shortly to erect hydraulic machinery at the pit mouth for the purpose of unloading the cages, and the plant for this purpose is already in course of construction. At the bottom of the shaft the loading and unloading of the cages is already done by hydraulic machinery, the natural gravitation of the water at the depth giving a pressure of 1,200 lbs. to the square inch. Another plant for coal washing is to be erected for the purpose of dealing with nuts, and double nuts principally. This will have a capacity of 100 tons an hour, and will be constructed on Humboldt’s system, the present slack wash being, I may say, Luhrig’s patent. At some time in the future it is also intended to erect a headgear and engines over the upshaft, similar to those already in existence at No. 1 shaft, and after Mr. Chambers had informed me that the company possesses at Denaby and Cadeby nearly 30 miles of sidings, and nearly 5,000 waggons, he pointed out to me the pipes used for taking steam down the pit to the hauling engines. These are 14 inches in diameter, constructed all of steel and electrically welded.