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Colliery Engineering

August, 1956

Manriding arrangements

After passing through the lamproom the workmen move out on to a covered railway-type platform which is the surface manriding terminus and, as can be seen from Fig. 21, adjoins the lamproom and other surface buildings. This arrangement ensures that underground men are completely under cover from the moment they enter the pithead baths until they leave again at the completion of their shift.

A single 2 ft. gauge track, on which manriding cars and supplies cars are carried, runs the whole length of the intake drift. The rails, which are laid on Tanalised sleepers set 30 in. apart, have a weight of 60 lb. per yard. On the surface, where a railway type turnout is fitted, the rails are secured to the sleepers by means of Elastic rail spikes, elsewhere ordinary dognails are used. Joints of the rails are opposite each other and the original burnt-ash ballast that the sleepers were set in is now being removed and the rails are being concreted in.

Cars traversing the drift are hauled by a direct rope haulage, the drive for which is a 200 h.p. Tinsley main-rope haulage gear. This is situated on the surface at the top of the drift in the same haulage-engine house as, and immediately behind, the cable-belt conveyor drive head.

The manriding cars are of Sheepbridge manufacture and they are open but have a protective high side next to the cable-belt conveyor. Each car has eight rows of backward and forward facing seats, each row of seats accommodating three men so that in a train of six cars a total complement of 141 men can be carried. The cars are fitted with an overspeed governor, the brakes operate on the rail tracks instead of the wheels, and there are manual brake controls at each end of the set. Maximum speed is 5½ m.p.h., and on the failure of any coupling the brakes are automatically applied.

Dewatering arrangements

Although there is no possibility of inundation, sufficient water has been encountered at Havannah to be of a nuisance value. At present, 15 pumps are employed keeping it under control, three in the Beaumont developing headings and 12 in the Low Main seam. Various types of pumps are employed including some of Mackley, Mono, Megator and Blagdon manufacture. All of these have been described in detail in previous issues of this journal and it should suffice to say that the Mackley is a centrifugal, the Mono a spiralled rotor in a spiralled stator, the Megator has eccentric cams in closed sliding shoes and the Blagdon is a centrifugal which can be driven by coalface drilling machines. The Mackley, which is the main pump, has a capacity of 300 g.p.m. with a 600 ft. head, the Mono deals with 25 to 80 g.p.m. at heads of 120 ft. to 350 ft., the Megator 50 g.p.m. at a 150 ft. head and the Blagdon is for dealing with nuisance face water.

The delivery range from the main pump is 6 in. in diameter, and the other pumps have steel pipelines of 2 in., 3 in. or 4 in. diameter. An interchangeable settling tank filters the water for the Mackley pump. The amount of water pumped appears to be fairly constant being only very slightly seasonal.

Ventilation

A Davidson & Co. Ltd. "Sirocco" fan is situated at right angles to the top of the return drift. A drawing of this fan can be seen in Fig. 26, and its position in relation to the drifts and other surface features can be seen in Fig. 21. The fan is of the two-stage, axial-flow type, being 92 in. in diameter and having a designed duty of 150,000 cu. ft. of air per min. at 6 in. water gauge and 360 r.p.m.

Electricity supply

Power for the mine is obtained from the North Eastern Electricity Board sub-station at Hazlerigg Colliery from a 20 kV feeder. It is supplied, through two power cables to the Havannah Colliery substation, where it is transformed to 3,300 V and then supplied at 3,300 V to surface and underground transformers where it is stepped down to 550 volts.

Results

At the present time, a total of 480 men are employed at Havannah and although the majority of the mine might be classed as still in the developing stage an average raised and weighed face O.M.S. is in the region of 1300 cwt. giving an overall O.M.S. of 522 cwt. As this productivity figure is well above twice the national average, success may justifiably be claimed for a venture which at inception was occasionally held to be overbold.

Acknowledgments

For permission to publish this article we are indebted to Mr. R. S. Pratt, M.C., Area General Manager, No. 1 Area, Northern (N & C.) Division, N.C.B., and we would very much like to express our thanks to Mr. J. Maughan, Manager of the colliery for his assistance in the preparation of this article.

Drawings and Photographs accompanying the article