South Yorkshire Times November 30
A Remarkable Headgear
Notable Developments at Denaby and Cadeby
The new winding gear which is being erected at the Denaby Main Colliery and is in an advanced stage of construction, is one of the most interesting modern engineering features to be found in the coal industry. It has been visited and examined by many mining engineers and both the designs and the building itself have been much admired.
The headgear which replaces an old stone structure is intended to raise coal direct from the Parkgate seam which at this mine lies at a depth of 722 yards. Hitherto, the coal from this seam has been raised by underground electrical winder to the Barnsley level and transferred to the No. 1 (Barnsley) shaft, a cumbersome process which has the effect of restricting the output of both seams.
The lay-out and designs for the new headgear which is now in the stage of construction shown in the above photograph taken a few days ago are the work of Mr. W. H. Chambers, lately managing director of the collieries, and the Late Mr. Ralph Williamson, formerly chief engineer.
The construction has been carried out from its commencement, some three years ago under the supervision of the present chief engineer. Mr. E. T. Hardy. It is anticipated that the winding gear, together with certain necessary remodelling of the screening plant will be in full operation by the end of next year.
A Unique Feature
The headgear is constructed entirely of reinforced concrete. The most interesting and important feature of the design is that this ponderous structure is self-supporting. Neither back-legs nor stays are used, the building being so designed that all the stress and strain as well as the over load are transmitted vertically to the foundations. The concrete beams carrying the outer or hydraulic decking floor have had to be cantilevered mainly, which has excited so much interest and curiosity in the engineering world The British coal industry and a bold innovation upon conventional pit headgear construction.
The headgear being built over the upcast shaft, has been made air-tight by means of air-locks, so that the return air from the mine is diverted from the loading deck, and the men are able to work in pure air The headgear is completely enclosed, but has a sufficiency of windows to give natural light.
“Decking by Hydraulics”
Hydraulic cages and decking machinery are now being fixed in the headgear. This machinery forms another very interesting feature of the plant. The winding cages are each of three decks each deck accommodating two half-ton curves. The full curves are automatically discharged and the winding cage automatically loaded with empty curves, by one operation of the decking machinery which pushes the empty tube into the winding cage, and the full tubs out of the winding cage and into the hydraulic cage. The two sections of the shaft are each fitted with hydraulic cages on either side one to discharge empties into the winding cage and the other to receive the full curves. Each hydraulic cage on the full side is fitted with air-tight piston decks and is lifted through a cast-steel air-lock to the banking level, thirty-three feet above the ground level.
At the same time and by the same operation the hydraulic cage on the empty side is also brought to the banking level to be charged with empties against the next arrival of the winding cage. The decks of the hydraulic cages are placed to fit the air locks and are practically air tight. A corresponding decking system is being installed in the pit-bottom, and creepers are being constructed to convey the empties back into the workings. The screening plant is being re-modelled to deal with the increased output which the new winding gear is intended to achieve and the arrangements for conveying the full curves from the landing deck to the screens are now being designed.
The shaft is being equipped with rigid steel conductor rails carried in pairs on buntons fixed across the middle of the shaft.
The concrete headgear is the work of Messrs. Peter Lind and Co., London. The whole of the hydraulic decking arrangements and the steel pulley framework at the top of the concrete structure have been designed by the Colliery Company´s engineering staff. They pulleys are eighteen feet each in diameter, weigh five and a half tons each, and are 65 feet 9 inches above the ground level.
The Winding Plant
A new winding engine only the drum of which (shown in the photograph) is yet fixed, has been built by Messrs. Robey and Co., of Lincoln.
It is designed to lift the load of three tons of coal from a depth of 722 yards in fifty seconds, which is equal to the best performances of winding machinery in this country. The cylinders are thirty-four inches in diameter, with a six-foot stroke, and steam pressure at 120 lbs to the square inch.
The drum is very massive weighing about 65 tons and semi-conical in shape, being from fourteen feet to twenty-four feet in diameter. Careful attention has been given to a very important detail – the position of the engine. This is elevated considerably above the conventional position in order to minimise the wear and tear of ropes by widening the angle of contact with the pulleys.
As about 1700 yards of steel rope will be required to operate this shaft the economy is quite appreciable. The engine house is to be of concrete and is being built by Messrs Peter Lind and Company. The foundation pillars for the engine are placed on a re-inforced concrete raft 55 feet by 51 feet by 2 feet thick. This is a special precaution to ensure stability in view of the proximity of the river.
Increasing Output
The whole plant is designed to deal with an output of a thousand tons per shift of seven hours. Normally there are eleven winding shifts at this mine. The diversion of so large an amount of winding traffic from the No. 1 shaft will enable the management to improve the output from the Barnsley bed by a hundred tons or so per shift and it is confidently expected that when the new plant is in full operation the Denaby colliery will have no difficulty in maintaining a steady output of 14,000 tons a week, with plenty of reserve. The electrical winding plant which is displaced by the new machinery will be left in the mine as a standby.
The steam for the new winding gear will be generated from nine new Lancashire boilers, 30 feet by 8, which have been put down by Arnold and Company of Barnsley, all fitted with super-heaters. This brings the number of boilers at this colliery up to fourteen, and Denaby may be said to have one of the most modern seam generating plants in the industry. For its various operations, steam, electricity, hydraulic and pneumatic power are all employed.
The ventilation plant is being re-modelled as well as the screening plant. A powerful fan of the double-inlet Sirroco type, capable of exhausting air at the rate of 250,000 cubic feet per minute, and driven by means of a direct-coupled high-speed steam engine, is to replace the old fan.
More Power at Cadeby
Interesting and important developments are also taking place at the associated Cadeby colliery, a mile away. Recently the Parkgate seam was reached there by drifting from the Barnsley bed. This seam, which is of most excellent quality, will be opened almost at once and a small output from it will be obtainable in the course of the next month or two. Meanwhile, the air-compression plant at the colliery is being considerably extended and additional power required for underground haulage will shortly be available. So far, two compressors each of 3,000 cubic feet free-air capacity, have been installed. They are of the Bellis-Morcom vertical high-speed steam driven type, with a pressure of 100 lbs to the square inch. The steam engines are equipped with the surface type of condenser having kinetic air extractors, and are capable of maintaining a 26 inch vacuum. The compressors are self-governing, and are separately housed.
All these additions to the equipment and plant of these powerful a highly productive collieries augur well for their continued prosperity and that of the neighbourhood in which they are situated. At present about 4,000 men are employed at the two collieries, and this figure will be substantially increased by means of the exploiting power of the machinery described in this article.