Joe Stocks has come up with another gem here. Thanks for suppling this information.
Whitwood Colliery.
The two shafts were sunk between 1871-78 and are situated about 2 ½ miles west of that point at which coal measures dip under the Permian. The Beeston shaft, a downcast , is sunk to a depth of 501 yards and is 14 ft. in diameter. This shaft was not sunk beyond the Silkstone Seam until 1914 and the present coal winding operations are restricted to this deepened portion, the output being subsequently raised to the surface through the Silkstone shaft, which is 74 yards distant. The latter shaft, also a downcast, is 415 yards deep and is 18 ft. in diameter and draws the entire output from both seams. The fact that both these shafts are downcasts is due to the seams here being ventilated from other of the company's pits.
Winding equipment at the Beeston shaft consists of a 16 ft. diameter by 6 ft. wide drum driven by 26 in. diameter by 5 ft. stroke cylinders. Post-type brakes are fitted and Barclay overwind-prevention gear. The winding ropes are the Lang's lay type, 3½ in. in circumference, and have a breaking strain of 45 tons. There is a clearance of 12 in. between the single decked cages, which carry two tubs, and run in pitch-pine guides, two being provided for each cage.
The winding engine for the Silkstone shaft has 42 in. diameter by 7 ft. stroke cylinders and is fitted with drop inlet valves and piston exhausts. This is coupled to a semi-conical drum---something of a rarity at a British colliery---, which rises from 17½ ft. to 20 ft. in diameter. No balance ropes are fitted. A maximum cage speed of 60 ft. per second is attained at 40 miles per hour. Ferodo-lined post-type brakes are fitted and Barclay overwind-prevention gear. Flattened strand ropes, by Latch & Batchelor, are used, having a circumference of 6 ¾ in. and a breaking strain of 200 tons. Each cage has three decks and accommodates four tubs per deck; the weight of the cage alone is 10 tons, the tubs and coal weighing 3 tons and 7 tons respectively. Eight pitch-pine guides, 6 in. square, are provided, two at each end of the cages, this heavy construction being necessitated by the small clearance, 2 ½ in., between the cages. Simultaneous decking is employed and the cages are provided with a tilting arrangement to assist the tubs to run out. The decks are fed by gravity-controlled drop cages, both at the top and bottom of the shaft. A view of one of the cages at the pit eye is reproduced above, and shows the extremely convenient arrangements that have been made for storing the spare cage and enabling it to be changed when necessary. It is kept in an annexe and, being under cover, it is protected from the weather and can be repaired under the best of conditions.
Both the headgears are of lattice-girder construction, that for the Silkstone being 90 ft. high and provided with 18 ft. pulleys, while the Beeston is 75 ft. high and has 16 ft. pulleys. King's detaching hooks are used in conjunction with all cages.
Power Plant.
The power house was completed in 1926 and consists of a handsome red brick building measuring 45 ft. by about 90 ft. A view of the interior is reproduced in Fig. 11 and shows the turbo air compressor and the two turbo-alternators with which it is equipped. The mixed-pressure turbo-compressor is a 12-stage machine by Daniel Adamson & Co. Ltd., having a maximum capacity of 11,500 cu. Ft. of free air per minute against a pressure of 80 lb. Per sq. in. When working at this rate the speed is 4,150 revs. per min. and 1,920 h.p. is absorbed. A 26 in. diameter inlet pipe is provided and a 13 in. outlet, the air main, which is of cast-iron, being 10 in. in diameter and carried down the Beeston shaft. An Arkon recorder (Walker, Crosweller & Co.) is fitted to the suction side of the machine so that the quantity of air being compressed can be read off at any moment. An automatic oil relay valve is incorporated to close the suction when a predetermined pressure is reached in the receiver pipe, this causing the compressor blading to operate in partial vacuum during periods of no load. Also a variable-speed governor is fitted which, within certain limits, enables the speed of the turbine to adjust itself for the demand for air. When the demand diminishes and a consequent rise in pressure occurs, a double diaphragm closes an oil relay and alters the adjustment of the governor balls. A drop in pressure has, of course, the opposite effect and causes the turbine to increase its speed. Steam and air pressures are recorded by Cambridge instruments and the compressor water-jacket temperature is also recorded. The intake air is passed through a Visco filter and is derived from the outside atmosphere. Condensing plant of the manufacturers own design is fitted, air extraction being effected by a water jet.
Both the turbo-alternators are by the General Electric Co. Ltd., and are similar machines, apart from the fact that one is designed for mixed pressure and the other for high pressure only. The capacity is 1,500 kW. in each case, and 3,300 volt 3 phase 50 cycle current is generated, the speed of the sets being 3,00 r.p.m. As the high pressure unit has less condenser water to deal with, a smaller motor is fitted---55 h.p. against the 90 h.p. motor provided for the mixed-pressure machine. Cole, Marchant & Morley low-level jet condensers are fitted to both these sets, the air being extracted by Delas equipment in the basement.
The mixed-pressure turbo set obtains its low pressure steam from three accumulators, which are fed by the two winding engines and two pit haulages situated at the surface. The pressure in the accumulators is kept at about 18lb. Absolute and the steam passes through a 30-in. dryer before entering the turbine. A Brown Boveri automatic voltage regulator is fitted.
For the d.c. supply a 5oo kW. 230 volt self-synchronising 6-phase rotary converter of G.E.C. manufacture is in service and derives its supply from a transformer in the basement. As standby for this set there is a motor generator set of similar capacity.
The power station is coupled with the Yorkshire Electric Power Company's 11,000 volt overhead mains from which energy is drawn for week-ends and holidays. This supply joins the colliery company's own overhead lines---also arranged for 11,000 volt transmission---which interlink their Whitwood, Snydale, Methley Junction, Don Pedro and Saville pits, at Snydale. Eventually their Walter Haigh pit will also be interconnected. As yet, however, the 11,000 volt transmission scheme has not been put into commission and the present connections are operated at 3,300 volts.
Boiler Plant.
A battery of 12 Lancashire boilers raises the steam supply, three operating at 100 lb. Pressure and the remainder at 160 lb. Per sq. in. Surplus steam from the high-pressure units is passed through a 5-in. reducing valve to the low-pressure main, which is thus kept at a constant pressure. For experimental purposes a Triumph mechanical stoker has been fitted to one boiler, the remainder being hand-fired with self-cleaning Crosthwaite furnaces. Six of the high-pressure boilers are fitted with superheaters (four Unit and two McPhail), and two banks of Green's economisers, each containing 400 tubes, serve the battery. Induced draught is furnished by duplicate 55-in. Sirocco fans, one on each side of the chimney, driven by 55 h.p. motors. Dampers are arranged so that the fans and economisers can be by-passed if necessary. Before entering the economisers the feed water is raised to 130 degree F. by exhaust steam from the boiler feed pumps and from a small De Laval turbine operating the condenser air-extraction pump of the turbo-compressor. Ultimately the feed is delivered to the boilers at 300 degrees F. Make-up water is pumped from the river and is quite satisfactory without treatment.
Haulages and underground equipment.
Reference has already been made to the two steam-driven haulages in connection with the low-pressure steam supply for the mixed-pressure turbo-alternator. These are situated near the Beeston shaft top; the smaller one, which functions in the Beeston seam, has 13 in. dia. By 26 in. stroke cylinders geared to a 6 ft. drum. The drum accommodates five laps of 1 ¼ in. diam. Rope and drives a horizontal shaft underground, from which the various haulages are operated through friction clutches. The Silkstone haulage has 20 in. dia. By 4 ft. stroke cylinders and an 18 ft. dia. Drum, and operates a vertical shaft underground. From this three rope drums are driven to serve the different districts.
Naturally the days of these rather cumbersome machines are numbered and in the Silkstone seam an important section of the underground haulage work has now devolved upon electrically driven units. Two sets of Bradley & Craven gears, each fitted with two fleeting wheels and driven by 3,300 volt 125 h.p. motor, have now been put to work and eventually all the main haulage underground will be done electrically. For auxiliary work compressed air units are largely used, although a certain number of electrically driven gears are in service in the intakes. In the neighbourhood of the face, however, compressed air is used exclusively, in main-and-tail gears having cylinder sizes ranging from 5 in. dia. And 8 in. stroke to 12 in. dia. and 18 in. stroke; these were supplied variously by Bradley & Craven Limited and Andrew Barclay & Co. Ltd.
At the coalface ponies are used, but Sullivan hoists are installed where the gates are steep. The coal is won from continuous longwall faces which are machine cut to a depth of from 5 ft. 6 in. to 6 ft. All the cutters are of the chain type and are operated by compressed air; they are chiefly of Mavor & Coulson manufacture, but a number of Jeffrey-Diamond and Sullivan machines are also employed. The coal is filled off by hand directly into the tubs, which are taken across the face. For the most part the coal is shot down, but in an endeavour to promote safety by minimising the quantity of explosives used, a number of ripping picks have been introduced in recent years. Gates are mostly spaced 33 yards apart---a few are 44 yards---and the machine-cut faces are worked end on. A top ripping is taken in the gate roads which are supported by side packs 4 yards in width, middle packs being inserted where necessary.
Miscellaneous Plant.
It has already been mentioned that these pits are ventilated by fans situated at other of the company's shafts. At Savile pit, which serves as one upcast, a double-inlet Sirocco fan, 112 in. in diameter, is installed and is driven by a 400 h.p. Robey cross-compound engine. A rope is incorporated, and when driven at its normal speed of 22 r.p.m. the fan delivers 250,000 cu. Ft. of air per minute against a 4 ½ in. water gauge. The other side of the pit is ventilated by two single-inlet Capel fans, one of which acts as standby. The first of these is 15 ft. in diameter and 5 ft. 6 in. wide and runs at 180 r.p.m. It is driven by a 3,300 volt 200 h.p. Mather & Platt motor and produces 240,000 cu. Ft. of air per minute at 3 ½ in. water gauge. The second fan is 16 ft. in diameter and 4 ft. 6 in. wide and is directly coupled to a Crossley gas engine having a speed of 160 r.p.m., the capacity being the same as the first Capel fan.
There are times when a coal storage yard can be an invaluable adjunct to a colliery, and Whitwood is particularly well provided for in this respect. The bay illustrated in fig. 12 is capable of accommodating 22,000 tons, but represents only a small part of the total space available. Portable conveyor loaders are used to load coal into the wagons, the concrete floor affording excellent shovelling facilities and having proved well worth its expense. It also affords good drainage.
The company owns seven shunting locomotives, five being of the six wheel-coupled type having 16 in. by 22 in. cylinders, and two of the Mersey Tunnel (Airedale Foundry) type (six-wheel-coupled with back and front bogie wheels) the cylinders being 19 ½ in. by 26 in. All these are kept in a proper state of maintenance in the locomotive repair shop, which is fully equipped for this purpose. In addition to this shop there is the usual range of fitting, smiths' and wagon shops and a sawmill. The fitting shop is particularly well equipped and contains seven lathes, one of which has a break bed to enable wagon wheels, &c., to be machined. Other equipment includes two planing machines, one shaping machine, one radial drilling machine, two vertical drilling machines and one slotting machine. Normally this shop is driven by two 15 h.p. electric motors but at weekends and during holidays, or in case of failure of the electric supply, a gas engine can be brought into service. The smiths' shop contains ten hearths, two punching and shearing machines, two power hammers (one electrical and one compressed-air), a Sullivan pick sharpener, a screwing machining and a small air compressor for supplying pneumatic riveters.
The cages for the whole colliery group are manufactured in this shop. Also the company builds its own tubs from parts bought out and effects its own wagon repairs, the shop for the later purpose measuring 78 ft. by 42 ft. and accommodating eight wagons at a time. This large shop is necessitated by the fact that all of the company's 3,634 wagons are sent here for repairs. Wood-working for the group is also concentrated at Whitwood, the saw mill being equipped with a reciprocating log saw, two circular saws, a band saw, a planing machine, and a mortising machine. Power is provided by two 25 h.p. motors with gas engine as standby. The use of gas for colliery power purposes is perhaps unusual, but is explained by the fact that the company are the proprietors of the local gas works which supplies the surrounding district. This leads us to another interesting activity of Henry Briggs, Son & Co. Ltd., and concerns the use of town's gas in a new lorry that they have added to their fleet of road vehicles for distributing their landsale coal.
Gas-driven lorry.
Although pioneers were not wanting to point out the advantages of using town's gas for motor transport before the war, it was a war-time expedient that gas for this purpose received anything like adequate recognition. The return of cheap petrol, however, discouraged further developments, as the bag containers which were used to store the gas on the vehicle afforded a very limited radius of travel. Fortunately the advantages offered by this fuel induced a number of workers---prominent among whom was Dr. C.M. Walter, of the city of Birmingham Gas Department---to continue with experiments to place its use on a more practical basis. Assistance came in the shape of alloy-steel bottles capable of safely withstanding internal working pressures of 3,000 lb. Per sq. in. Although not heavy in relation to their capacity the weight of these vessels is still sufficient to preclude the use of gas propulsion to other than the heavier type of vehicle. A view of the new lorry is produced in fig. 13; it was manufactured by Leyland Motors Limited to the specified requirements of the colliery. The chassis is of the 6-ton "Beaver" type (unladen weight 5 tons 10 cwt.) and differs little from the standard petrol-driven design apart from the gas equipment. The pistons have, however, been modified to give a slightly higher compression ratio than is customary with an engine of this type run on petrol fuel. The engine has six- 4 ½ in. dia. by 5 ½ in. stroke cylinders and is coupled to the four-speed gear-box through a 16 ½ in. single dry-plate clutch. In top gear the ratio is 7.33 to 1, a speed of 30 m.p.h. being achieved at 2,000 r.p.m. First speed has a gear ratio of 35 to 1 and reverse 40.8 to 1.
The gas equipment consists of 4 alloy-steel containers, a double reducing valve, a mixing valve, and the necessary high-pressure piping. Apart from the reducing valve, which is of Belliss manufacture, this equipment was supplied by the Chesterfield Tube Company. The cylinders are about 8 in. outside diameter, 73 in. long and have a wall thickness of 0.22 in.' the weight when empty being 119 lb. As the internal volume is 1.76 cu. Ft. and the working pressure 3,000 lb. per sq. in. the volume of free gas contained is 352 cu. Ft. After being fed through the master stop valve the gas is passed to the double reducing valve at the rear of the cab, where it is reduced to sub-atmospheric pressure. It is then led to the mixing valve, the proportion of gas to air being controlled by a diaphragm. In this the gas is taken to the periphery in order to avoid stratification and so ensure correct distribution. Control is effected by the ordinary acceleration pedal which is coupled to the gas throttle. A pressure gauge is fitted in the driver's cab to give warning when the gas is running low. In order that the lorry can, in case of emergency, be operated on petrol, a fuel tank is mounted at the rear end of the cab, the change-over being effected by a Bowden control. This operates a sliding dog which, in turn, connects the foot accelerator with either the gas or petrol throttle.
A view of the charging station is given in fig. 14. The plant here is essentially of an experimental nature and has been so erected that it can easily be modified. It consists of a Peter Brotherhood 4-stage submarine-type compressor capable of confining 6,000 cu. Ft. of free gas per hour against a pressure of 3,000 lb. per sq. in., and three containers* each of 5 cu. Ft. capacity, so that each is able to store 1,000 cu. Ft. of free gas. The compressor is rope driven by a 35 h.p. motor, and the length of time taken to fill the lorry is about 3 minutes.
As yet the lorry has not been running for a sufficiently long period for extract costs to be established, but we were informed that when costing the gas at 2s. 2d. per 1,000 cu. Ft. compressed, it would be safe to say that the cost of operating on coal gas is equivalent to using petrol at 8d. per gallon. It is proposed to use the lorry over an area of 20 miles radius, this including Bradford, Leeds, Wakefield, and Pontefract. Actually the lorry is able to accomplish a journey of about 50 miles per charge of gas.
* Since our last visit the three vessels have been replaced by a single large container capable of storing 3,000 cu. Ft. of gas.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Note:-
Information obtained from Briggs advert in colliery engineering mag.34.
Letter re-supply of gas for Normanton.
Dear Sirs,
Your letter of September 16th 1884, and Normanton Gas Co.
I enclose Normanton Gas Act also agreement between Normanton Gas Co.and Henry Briggs Son and Co. Ltd.as to supply of Gas in Normanton, and shall want your advice as to the power of the Whitwood Chemical Co.Limited to supply Gas for fuel in the Township of Normanton.
The directors of the last mentioned Company desire to be assured of this point before entering into any contract for the supply of Gas.
All being well I shall be in Wakefield on Thursday morning next when I will call upon you.
Yours faithfully,
Mr H Phillips.
Sec.
Messrs Scanly Wilson & Leatham,
Wakefield,
Letter.
Copyright: all rights reserved.
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