Collieries Operated by
Broken Hill Proprietary Company Limited.
Situated six miles from Cessnock, and by rail 36 miles from Newcastle, Elrington Colliery is worked on modern lines. Surface structures are of brick or fabricated steel. The main pulley frame is 78 ft. high to the centre of the winding pulley, and the pulleys are 16 ft. in diameter. The area of the holding is 3,900 acres, including 1,520 acres freehold. It is well served by rail and road facilities, including a three-mile railway owned by the Company. The colliery is owned by B.H.P. Collieries Pty. Ltd., in which Hebburn Ltd. is a shareholder.
Coal production was started in 1930. Two shafts each 18ft. in diameter and lined with concrete throughout pierced the top Greta seam at a depth of 1,200ft. The seam, including bands, is 23ft. thick, but at the present time only the bottom portion, up to a thickness of 12 ft., is being worked. The first working is to a height of seven feet, the remaining five feet is taken as "tops."
No. 1 shaft, which is upcast, and which will ultimately be the main hauling shaft, has not yet been fitted up for coal drawing. No. 2 shaft by which the whole of the output is being raised, is provided with an electric winding engine with Ward Leonard control operated automatically from the top and bottom.
The workings are lime dusted throughout to obviate explosion and ignition of coal dust, and to improve the mine lighting. Main tracks are laid with 60-lb. rails. In working places 30-lb. rails are used, and to facilitate loading of the skip at the working face extension rails free to slide on ordinary rails are employed.
The bord-and-pillar system is used in working. Both bords and cut-throughs are six yards wide with pillars 29 yards by 40 yards.
The workings are laid out in panels to enable quick and efficient sealing off if necessary. Supplies of bricks, sand and water are kept in readiness at the entrance to each panel.
Underground haulage is done by 8-ton battery-operated electric locomotives. Five locomotives and seven batteries handle the whole of the output from the face to the pit bottom. The batteries are charged each shift, in well-lighted sub-stations underground.
The 3-ton skips are of all-steel construction. They operate on a 3 ft. 6 in. track. Their semi-automatic couplers act as buffers, and their ends are splayed so that when coupled a man may stand between them without being "squeezed." Trains of from 14 to 20 loaded skips are made up near the coal face, and hauled by locomotives to No. 2 shaft. The skips are hauled up the shaft at a speed of about 600ft. per minute.
On reaching the surface, the loaded skips gravitate from the shaft to a tumbler of the semi-rotary type. This transfers the coal to the conveyor, while from the tumbler a creeper elevates the empty skips to a point from which they gravitate back to the shaft.
As the coal travels over the conveyor, which is made up of wire screen cloths of 1¼ in. in mesh, the small coal falls through and is conveyed to the wagons. The large coal is delivered on to a rubber belt conveyor, where it is cleaned and delivered into 12-ton railway wagons for transport to the steel works.
Electric motive power and lighting are supplied to the colliery by the Hebburn Colliery. Underground employees are provided with electric cap-type safety lamps; examining officials carry flame-type safety lamps.
Compressed air pumps are used in the workings. These deliver water to a sump at No. 2 shaft bottom, where it is picked up by a 12-stage electrically-operated turbo pump running at 3,000 r.p.m., and delivering 100 gallons a minute against a head of 1,200ft. Ventilation is effected by an electrically-driven fan, capable of delivering 400,000 cubic feet of air a minute.
Elrington's present output is 1,100 tons of coal a day. Fully equipped the colliery will produce 3,000 tons a shift. The number of employees including staff officers is 300.
John Darling Colliery near Belmont, N.S.W.
John Darling Colliery is situated 12 miles south from Newcastle. The area of the holding is 10,000 acres, of which 4,320 acres are under the Pacific Ocean. The area extends for 9½ miles north and south of the shafts.
The sinking of the two shafts each of 22 ft. diameter was begun in 1925. With the exception of 20 ft. at the surface, the shafts are concrete lined. The Victoria Tunnel seam was bottomed on June 10, 1927, at a depth of 650ft., and of a thickness of 10ft. 3 in., of which 5ft. 9 in. is workable. The Borehole seam was bottomed on October 21, 1927, at a depth of 870 ft., with a thickness of 6 ft. 8½ in. and a working section of 5 ft. 8 in. In all, eight seams were proved, with a total thickness of 130ft.
The surface buildings and colliery headgear were fabricated from steel rolled at the Newcastle Steel Works. The headgears at both shafts rise to a height of 90 ft. to pulley-wheel centres. The downcast shaft is used for the Victoria seam, and the upcast shaft for the Borehole seam.
The ventilation fan is designed for 600,000 feet of air per minute at 4 in. water gauge. The mine is lime-dusted throughout. The six-stage centrifugal pump has a capacity of 25,000 gallons an hour at a head of 650ft.
The average daily output is 2,400 tons, the record being 2,560 tons. Of this tonnage, 2,150 tons are produced from the Victoria Seam, and 350 from the Borehole Seam. The whole of the coal is hand-mined at present.
Pillars are being worked simultaneously with bords, 50 per cent. of the output being pillar coal. Practically the whole of the seam is being extracted.
Haulage is by direct ropes of the endless type, and 8-ton battery locomotives. The total length of endless rope used in the mine at present is 5,940 yards.
The haulage plant is designed for a working load of 17 tons, the double deck cages carrying three skips on each deck. The skips, after being weighed, run on to a double strand creeper chain, fitted with tilting spurs. The skips are elevated to a point where they gravitate to any of four mechanically-operated tipplers. Shaking screens separate the large and the small coal. The large coal is delivered on to two picking belts each 4 ft. 6 in. wide and 80 ft. long. The clean coal passes through a chute into wagons for despatch to the Newcastle steel works.
Electric power is generated at the colliery, the total capacity being 1,355 k.v.a. Power is transmitted from John Darling Colliery to the Burwood Colliery, six miles distant, and to Lambton Colliery, three miles away. Employment represents 535 men.
Burwood Colliery near Belmont, N.S.W.
Burwood Colliery was taken over from the Scottish Australian Mining Co. on September 21, 1932. The area of the property is 3,360 acres, of which 1,462 acres underlie the Pacific Ocean. The main shaft goes down 600 ft. in the Borehole seam, which is the only seam yet worked. The thickness varies from 5 ft. 6 in. to 7 ft., including penny bands. The Victoria Tunnel seam is found at a depth of 320 ft., with a thickness of 7ft. 5in.
A scheme of modernisation, involving a change-over from steam to electrical operation, was planned when the colliery was taken over. The scheme, which has now been completed, has greatly increased the efficiency of the colliery operations.
The Burwood Colliery is equipped with a complete mechanical coal-cutting plant, 90 per cent. of the 1,450 tons mined per day being machine-cut. Eight machines of the short wall type are in use. In addition to under-cutting the whole of the coal, boring is done mechanically, leaving only the actual filling of the coal to be done by hand.
The electric power supplied by John Darling Colliery is stepped up to 11,000 volts, enabling the whole of the Burwood Colliery appliances, with the exception of winding engine, to be electrified.
The pit bottom is so designed that all full skips are handled on one side of the shaft, while the empties are dealt with on the other side, returning by gravity and mechanical creeper chains.
The pit bottom supports are 24 x 7½ R.S.J.'s on 10 x 8 R.S.J. columns, the whole being fireproof and concreted. The dimensions are 24 ft. wide by 20 ft. high.
The pumping plant comprises two pumps: one pump, which delivers water through an 8-inch borehole, has a 40,000 gal. capacity per hour; the pump delivering the water at the main shaft has a capacity of 25,000 gals. per hour. The Walker ventilating fan produces 190,000 cubic feet of air a minute, with a water gauge of three inches.
The fan speed is regulated by hydraulic coupling controlled by a hand-operated wheel, giving an economy in electric power.
The screening plant is operated by motors from a central control point, the various units being synchronised to suit the output. The coal is discharged from the skips on to a shaking screen for separation of the large coal from the small. The large coal is shaken on to two travelling belts, 80 ft. long by 4 ft. 6 in., rubbish being picked off by hand. The clean coal goes on by conveyor to the chute for delivery to the coal wagons. Small coal is received on the scraper conveyor below the shaking screen, which removes the fine coal or "duff." Under Burwood's system, all coal is treated as "large" for cleaning purposes. The screened small coal is mixed again on the scraper conveyor, which delivers to the wagons the unscreened coal. Thus the difficulty in cleaning unscreened coal owing to the mixture of large and small coal on the picking belts is overcome.
The underground haulage system is all of endless ropes, with a total length of 10 miles. Transport is by 7-ton battery locomotive. Bord and pillar working is employed. Under the ocean, bords are six yards and pillars eight yards wide. The output of coal is 1,100 tons a day. There are 390 employees at Burwood Colliery.
Lambton Colliery near Belmont, N.S.W.
Lambton Colliery, owned by The Broken Hill Proprietary Co. Ltd., is situated nine miles south of Newcastle. The colliery is connected by rail to the steel works. The area of the property is 5,400 acres, and holds two seams of coal — the virgin Victoria Tunnel or Burwood seam at a depth of 200 ft. in the main shaft, and the Borehole seam, found at a depth of 430 ft. from the surface.
Early in 1936, the development of the Victoria Tunnel seam was commenced on a basis of complete mechanisation. In the first ten months, 97,000 tons of coal were won solely from narrow working places incidental to the opening up of the new colliery.
The plant operating at present is three mechanical loaders, two coal-cutting machines, and three locomotives.
The electrically-operated coal-cutter is of the Arcwall type. The machine is worked from the track, and can be arranged to cut anywhere in the coal seam between the floor and roof. This type of machine can be rapidly transported from one working place to another, and can commence work as soon as it reaches the working place.
The machine weighs eight tons. The overall width is 70½ in., length (without cutter bar) is 13 ft. 1 in., gauge of track 42 in., and wheel base is 36 in. The cutting motor is of 50 h.p. The depth of the cut made by the machine is eight feet, the cut producing 40 tons of coal. Shot holes are drilled electrically; an eight-foot hole is completed in two minutes.
The track type loaders are composed of two units — the front or carrying conveyor and the rear or discharging conveyor. Under favourable conditions, they will load 300 tons per day. The machine is operated by two motors, each of 15 h.p.
Underground traction is by storage battery locomotives weighing 15,000 lbs.
The whole of the face tracks are 30lbs. to the yard rails, supported throughout on steel sleepers with special steel clips made up at the colliery. The points and crossings used throughout have been made on the job.
The skips used were designed and manufactured at the colliery. They are made of flat steel bodies on channel underframes, the whole being continuously welded throughout. The wheels and axles are fitted with Timken taper roller bearings. Their capacity is 2¾ tons nett.
The screening plant consists of a rotary dump which tips on a crawl feed which distributes the coal over a screen, the oversize going on to two steel picking belts 75ft. long, 4ft. 6 in. wide. These discharge on to a loading conveyor, which in turn discharges into the wagon through a chute. Oversize coal on this conveyor passes through a coal breaker into the wagon. The small coal, after passing through the screen, is discharged on to a steel flight cross conveyor, which in turn delivers on to a rubber belt and into a storage bin. Provision is made at the discharge end of the belt for the removal of any duff if necessary.
The electric power used at Lambton Colliery is supplied by John Darling Colliery, situated three miles south of Lambton. The power is transmitted at a pressure of 6,600 volts to a sub-station at Lambton Colliery, where it is stepped down to 2,200 volts for transmission underground. At a sub-station adjacent to the pit bottom, the voltage is further reduced to 415 volts.
These notes are reprinted from Shapes & Sections Handbook, Broken Hill Proprietary Company Limited, 1937
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