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April, 1932
The Hartley Main Collieries Limited
At this Group of Collieries an Extensive Scheme of Reorganisation has been Undertaken ; New Shipping facilities are being Constructed, and Electric Equipment aggregating nearly 7,000 H.P. has been added to the Plant during the last year.
Seaton Delaval
The surface re-equipment at this colliery has been practically restricted to the screening plant. There are four coal-drawing shafts — the C & D, and E & F — and a gantry has been erected between the two pairs so that the whole of the coal can now be centralised on the E & F screens. These have been totally electrified and remodelled to prevent breakage, so that the coal may be marketed in the best possible condition.
Underground, an extensive system of machine mining has been applied, some of the faces, indeed, having been 100 per cent. mechanised. The seam worked is the Low Main, which is about 2 ft. 6 in. in thickness and lies at a depth of 102 fathoms. The longwall faces are arranged on the double-unit principle, each face being 100 yards in length and served by an Eickhoff M.T. 15 shaker conveyor. Both these conveyors discharge into a 26-in Clephan belt conveyor in the gate, which can be extended to a maximum limit of about 200 yards. To enable the trunk conveyor to be lengthened conveniently a set of belt lengths is kept handy in the gate road, graduated in multiples of the cut, it being a few minutes work to insert the make-up piece. To facilitate this operation a telescopic tail-trough is provided, which is expanded or contracted through a set of gears operated by a handle.
A Siemens-Schuckert rotary drill is employed on each face, the holes being placed at intervals of about 5 yards and bored 4 ft. 6 in. in depth. The number of holes actually charged, however, depends on the effectiveness of the shots, such being the rapidity and ease with which the holes are drilled that this system has proved to be the most economic. All drilling work is finished in the course of the shift. The drills are provided with Widia-tipped bits, the special qualities of which material were discussed in a recent article contributed to these columns by H. Muhlhaus. Briefly, however, the advantages of using these bits compared with those made of steel are that some 40 per cent, is saved in drilling time, due to the higher cutting rate, and no stops are necessary for bit-changing, since the bits, in this instance, are used nine weeks before they require to be reground.
Kirving is accomplished by British Jeffrey-Diamond chain machines fitted with 5-ft. jibs. The cut is 5 in. deep and is made in a band of coarse coal at the bottom of the seam. A team of three men is employed in making the cut — a first and second machine man and a clearer-out; in addition a timber man is engaged in taking down and resetting the S.F. steel props with which the faces are supported. These are set at intervals of 3 ft. 6 in. in the direction in which the face is travelling and 4 ft. between adjacent props.
The roadways at this colliery are for the main part supported by girders erected on wood props, but in the cross gates, where the timber props are apt to break, a trial is being made with Bromford steel props.
Dudley Colliery.
At this pit, which has been completely overhauled both above and below ground, the old gravity-type bar-screens have been demolished and a modern screening plant, formerly in operation at New Delaval, re-erected in its place. A view of this plant on its original site at New Delaval is reproduced in Fig. 21, and shows the portions, between the dotted lines, that were transported to Dudley. The steel headgear was also dismantled and re-erected at the No. 1 Pit at Dudley. Dismantling of the screens was commenced on January 5 last year and the plant was transferred to Dudley, re-erected, and two screening units placed in commission by June 20, 1931. The plant comprises four coal tipplers and one stone tippler, and four shakers and picking belts for handling best, trebles, double and single nuts. A cross belt is also provided for dealing with the smalls. Lowering jibs were added to the picking belts to prevent breakage of the coal, this being the only improvement necessary.
The headgear and heapstead replaced an old wooden erection which was demolished as soon as the newer equipment was placed in position, the whole change-over being made without any interruption to coal-drawing whatsoever. The planning of a substitution of this kind calls for the greatest care and ingenuity, due to the site being encumbered with so much material, and it speaks very highly for the proficiency of the engineering staff that the whole of this awkward piece of work was carried out without any hitch.
A new winder house was built to complete these improvements and furnished with a new winder by John Wood & Sons Ltd., of Wigan, the electrical portion having been supplied by the English Electric Co. Ltd. This equipment is of the double-drum clutch type, with 12-ft. diameter drums and 330-H.P. motors, and can be arranged to draw coal from any of the various seam offsets. A compressed-air engine is incorporated to operate the multiple-tooth clutch on the loose drum, and a very fine rope adjustment is possible — within one inch. For normal working, the brakes, which are also air operated, are so arranged that there is a pair of opposed brakes for each drum, all acting simultaneously. When it is required to change the winding level a further pair of brakes, operated by hand, is brought into use. These act on the loose drum, leaving the winding drum free to be wound to the new level. When this is accomplished the clutch is re-engaged, and, after the air brakes have been applied, the hand brakes are released and the winder is ready for use. The actual time required for this operation does not exceed one minute.
The engine house has been so designed that all the auxiliary gear the compressor, reversing switches, transformer, controller, &c — is housed in the basement. Figs. 15 and 16 indicate the old plant and the new from the same angle.
Miscellaneous Equipment.
Like most colliery pumping plants the drainage system at the Hartley Main group has necessarily been developed according to the dictates of expediency. A unit that has recently been added is a 1,000-g.p.m. 8-stage Drysdale pump installed at the Seaton Delaval pit. It is driven at 1,140 r.p.m. by a 325-H.P. motor and operates against a head of 750 ft. A new steel main has been provided, 8-in. in diameter, the joints being made by screwed-on and welded flanges. In all there are about a dozen main pumping units scattered through the colliery group, ranging from 450 to 1,000 g.p.m. capacity and working on heads varying from 500 to 800 ft. During the last year a number of electrically driven Drysdale self-priming pumps (Fig. 18) have been introduced for in-bye use. These can be allowed to pump the standage dry and automatically pick up their load again as the water accumulates. Considerable economy in pump attendance is thus effected, particularly with face conditions.
Above ground the completeness of the plant is illustrated by the particularly full range of equipment in the engineering shops. These have now been centralised at Seaton Delaval Colliery. The view reproduced in Fig. 23 indicates the excellent lines on which the central shops have been planned; the lighting is all that can be desired, and there is a general air of space and cleanliness — the wood-block floor contributing towards the latter effect.
In the laboratory, a view of which is reproduced in Fig. 22, analyses are made of the various seams, roadway dusts and pit gases, and a check is also kept on the quality of lubricating oils and greases, &c., supplied.
The company also owns a modern brickworks capable of producing 120,000 bricks per week. Quite recently a Bradley & Craven double-press machine, having a capacity of 2,000 common bricks per hour, has been added to the plant (Fig. 17). Wire-cut bricks can also be supplied.
Coal-Loading Plant.
Drawings of the new coal-loading plant under course of construction on the Tyne are shown in Fig. 24. Coal will be brought by private line to the hopper, from which it will be delivered, by a jig feed, to two 42-in, rubber belt conveyors. These connect with two further belts on the radial bridges, and the coal is delivered to the vessel holds through Hancock anti-breakage chutes. Each of the two plants is designed to handle 500 tons of coal per hour, a noteworthy feature being the extreme mobility of the loading points, which have a lateral range of 90 ft., a vertical range of 60 ft., and are capable of extending 60 ft. athwart the ship. This not only ensures rapidity of loading but eliminates to a great extent the necessity to move the vessel. When the anti-breakage chutes are not required at the end of the booms, the latter may be swivelled in a complete circle and retain the running angle of about 30° quite automatically. Awkwardly placed bunker hatches can thus be reached with great facility, and much time is saved in bunkering vessels. A photographic view of a model of the new shipping plant which has been constructed is shown in Fig. 25.
The scheme has been designed under the supervision of Mr. R. F. Hindmarsh, M.Inst.C.E., Chief Engineer to the Tyne Commissioners, and Mr. C. A. Nelson, M.I.M.E., to whom we have already referred; F. Turnbull & Company, of Heaton, who have specialised in this type of coal-loading plant, are carrying out the construction.
May 1932: WASHERY AT EAST CRAMLINGTON. — It has been brought to our notice in connection with our article on the Hartley Main Collieries Limited that the washery illustrated in the April issue was not of the Baum type as indicated in the caption. In point of fact, this plant was built by Campbell, Binnie, Reid & Company twenty-one years ago. Since that time it has been working double shifted, three shifts, indeed, being worked at the present time. The washery is now being modernised and extended by the original makers. The existing units are being fitted with Reid's patent air agitation plungers and a further washing unit is being added. Also a Reid's fines extracting plant is being incorporated to remove the fines before washing. This latter plant is claimed to be of unique design in that it cannot possibly choke up even when dealing with wet coal containing fines under 1/30 in.
Drawings and Photographs accompanying the article
Article reproduced from a copy of the magazine held at National Mining Museum Scotland, Newtongrange, Midlothian.
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